0001193125-21-062279 | 10-K | XBRL Viewer

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Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	ZLAB
Entity Registrant Name	ZAI LAB LIMITED
Entity Central Index Key	0001704292
Entity Common Stock, Shares Outstanding		88,592,343
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Title of 12(b) Security	American Depositary Shares, each representing 1 Ordinary Share, par value $0.00006 per share
Security Exchange Name	NASDAQ
Entity File Number	001-38205
Entity Incorporation, State or Country Code	E9
Entity Address, Address Line One	4560 Jinke Road
Entity Address, Address Line Two	Bldg. 1, Fourth Floor Pudong
Entity Address, City or Town	Shanghai
Entity Address, Country	CN
Entity Address, Postal Zip Code	201210
Document Annual Report	true
Document Transition Report	false
Entity Tax Identification Number	98-1144595
Entity Small Business	false
Local Phone Number	6163 2588
City Area Code	86 21
Entity Public Float			$ 6.2
ICFR Auditor Attestation Flag	true

Consolidated balance sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 442,116	$ 75,932
Short-term investments	744,676	200,000
Accounts receivable (net of allowance of nil and $1 as of December 31, 2019 and 2020, respectively)	5,165	3,791
Inventories	13,144	6,005
Prepayments and other current assets	10,935	6,736
Total current assets	1,216,036	292,464
Restricted cash, non-current	743	510
Investments in equity investees	1,279	2,398
Prepayments for equipment	274	440
Property and equipment, net	29,162	21,353
Operating lease right-of-use assets	17,701	15,071
Land use rights, net	7,908	7,655
Intangible assets, net	1,532	1,148
Long term deposits	862	377
Value added tax recoverable	22,141	13,737
Total assets	1,297,638	355,153
Current liabilities:
Short-term borrowings		6,450
Accounts payable	62,641	22,660
Current operating lease liabilities	5,206	4,351
Other current liabilities	30,196	13,174
Total current liabilities	98,043	46,635
Deferred income	16,858	2,881
Non-current operating lease liabilities	13,392	10,977
Total liabilities	128,293	60,493
Commitments and contingencies (Note 22)
Shareholders' equity
Ordinary shares (par value of $0.00006 per share; 500,000,000 shares authorized, 68,237,247 and 87,811,026 shares issued and outstanding as of December 31, 2019 and 2020, respectively)	5	4
Additional paid-in capital	1,897,467	734,734
Accumulated deficit	(713,603)	(444,698)
Accumulated other comprehensive income (loss)	(14,524)	4,620
Total shareholders' equity	1,169,345	294,660
Total liabilities and shareholders' equity	$ 1,297,638	$ 355,153

Consolidated balance sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 1	$ 0
Ordinary shares, par value	$ 0.00006	$ 0.00006
Ordinary shares, shares authorized	500,000,000	500,000,000
Ordinary shares, shares issued	87,811,026	68,237,247
Ordinary shares, shares outstanding	87,811,026	68,237,247

Consolidated statements of operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 48,958	$ 12,985	$ 129
Expenses:
Cost of sales	(16,736)	(3,749)	(43)
Research and development	(222,711)	(142,221)	(120,278)
Selling, general and administrative	(111,312)	(70,211)	(21,576)
Loss from operations	(301,801)	(203,196)	(141,768)
Interest income	5,120	8,232	3,261
Interest expenses	(181)	(293)	(40)
Other income, net	29,076	938	59
Loss before income tax and share of loss from equity method investment	(267,786)	(194,319)	(138,488)
Income tax expense
Share of loss from equity method investment	(1,119)	(752)	(587)
Net loss	(268,905)	(195,071)	(139,075)
Net loss attributable to ordinary shareholders	$ (268,905)	$ (195,071)	$ (139,075)
Loss per share — basic and diluted	$ (3.46)	$ (3.03)	$ (2.64)
Weighted-average shares used in calculating net loss per ordinary share — basic and diluted	77,667,743	64,369,490	52,609,810

Consolidated statements of comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (268,905)	$ (195,071)	$ (139,075)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments	(19,144)	1,958	2,212
Comprehensive loss	$ (288,049)	$ (193,113)	$ (136,863)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Consolidated statements of comprehensive loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Other comprehensive income, tax	$ 0	$ 0	$ 0

- Definition

Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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+ Details

Consolidated statements of shareholders' (deficit) equity - USD ($) $ in Thousands	Total	Global Offering	Ordinary Shares	Ordinary Shares Global Offering	Additional Paid In Capital	Additional Paid In Capital Global Offering	Subscription Receivable	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Balance at Dec. 31, 2017	$ 235,171		$ 3		$ 345,270		$ 0	$ (110,552)	$ 450
Balance, Shares at Dec. 31, 2017			49,912,570
Issuance of ordinary shares upon vesting of restricted shares			$ 0		0		$ 0
Issuance of ordinary shares upon vesting of restricted shares, Shares			338,332
Exercise of shares option	$ 196		$ 0		196
Exercise of shares option, Shares	256,065		256,065
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost	$ 140,348		$ 0		140,348
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost, Shares			7,500,000
Share-based compensation	12,229				12,229
Net loss	(139,075)							(139,075)
Foreign currency translation	2,212								2,212
Balance at Dec. 31, 2018	251,081		$ 3		498,043			(249,627)	2,662
Balance, Shares at Dec. 31, 2018			58,006,967
Issuance of ordinary shares upon vesting of restricted shares			$ 0		0
Issuance of ordinary shares upon vesting of restricted shares, Shares			539,733
Exercise of shares option	$ 1,055		$ 0		1,055
Exercise of shares option, Shares	670,939		670,939
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost	$ 215,346		$ 1		215,345
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost, Shares			9,019,608
Share-based compensation	20,291				20,291
Net loss	(195,071)							(195,071)
Foreign currency translation	1,958								1,958
Balance at Dec. 31, 2019	$ 294,660		$ 4		734,734			(444,698)	4,620
Balance, Shares at Dec. 31, 2019	68,237,247		68,237,247
Issuance of ordinary shares upon vesting of restricted shares			$ 0		0
Issuance of ordinary shares upon vesting of restricted shares, Shares			225,768
Exercise of shares option	$ 6,664		$ 0		6,664
Exercise of shares option, Shares	899,361		899,361
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost	$ 280,549	$ 850,691	$ 0	$ 1	280,549	$ 850,690
Issuance of ordinary shares upon initial public offering/ follow-on public offering, net of issuance cost, Shares			6,300,000	12,148,650
Share-based compensation	24,830				24,830
Net loss	(268,905)							(268,905)
Foreign currency translation	(19,144)								(19,144)
Balance at Dec. 31, 2020	$ 1,169,345		$ 5		$ 1,897,467			$ (713,603)	$ (14,524)
Balance, Shares at Dec. 31, 2020	87,811,026		87,811,026

Consolidated statements of shareholders' (deficit) equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share issuance cost upon initial/follow-on public offering	$ 746	$ 854	$ 652
Global Offering
Share issuance cost upon initial/follow-on public offering	$ 5,698

Consolidated statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net loss	$ (268,905)	$ (195,071)	$ (139,075)
Adjustments to reconcile net loss to net cash used in operating activities:
Allowance for doubtful accounts	1
Inventory write-down	29	0	0
Depreciation and amortization expenses	4,640	3,766	1,650
Amortization of deferred income	(312)	(312)	(312)
Share-based compensation	24,830	20,291	12,229
Share of loss from equity method investment	1,119	752	587
Loss (gain) on disposal of property and equipment	(21)	15	1
Noncash lease expenses	4,318	2,831
Changes in operating assets and liabilities:
Accounts receivable	(1,375)	(3,701)	(90)
Inventories	(7,168)	(6,001)	(4)
Prepayments and other current assets	(4,199)	(1,125)	(4,794)
Long term deposits	(485)	180	(250)
Value added tax recoverable	(8,404)	(5,693)	(2,982)
Accounts payable	39,981	(14,772)	28,464
Other current liabilities	(10,977)	9,136	7,056
Operating lease liabilities	(3,416)	(2,436)
Deferred income	14,289	1,129	(18)
Net cash used in operating activities	(216,055)	(191,011)	(97,538)
Cash flows from investing activities:
Purchases of short-term investments	(949,161)	(277,640)	(200,350)
Proceeds from maturity of short-term investments	405,000	277,990
Purchase of equity method investment			(2,086)
Purchase of property and equipment	(10,130)	(6,035)	(10,015)
Purchase of land use rights		(7,836)
Purchase of intangible assets	(539)	(1,371)	(103)
Net cash used in investing activities	(554,830)	(14,892)	(212,554)
Cash flows from financing activities:
Proceeds from short-term borrowings		7,252	3,643
Repayment of short-term borrowings	(6,527)	(4,351)
Proceeds from exercises of stock options	6,664	1,055	196
Proceeds from issuance of ordinary shares upon public offerings	1,137,683	216,200	141,000
Payment of public offering costs	(5,380)	(854)	(692)
Net cash provided by financing activities	1,132,440	219,302	144,147
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	4,862	91	(763)
Net (decrease) increase in cash, cash equivalents and restricted cash	366,417	13,490	(166,708)
Cash, cash equivalents and restricted cash — beginning of the year	76,442	62,952	229,660
Cash, cash equivalents and restricted cash — end of the year	442,859	76,442	62,952
Supplemental disclosure on non-cash investing and financing activities:
Payables for purchase of property and equipment	788	416	1,709
Payables for intangible assets	70		225
Payables for public offering costs	1,063
Supplemental disclosure of cash flow information:
Total cash and cash equivalents and restricted cash	442,859	76,442	62,952
Interest paid	$ 189	$ 288	$ 36

Organization and principal activities

12 Months Ended

Dec. 31, 2020

Organization and principal activities

Organization and Principal Activities

1.	Organization and principal activities

Zai Lab Limited (the “Company”) was incorporated on March 28, 2013 in the Cayman Islan

s as an exempted company with limited liability under the Companies Law of the Cayman Islands. The Company and its subsidiaries (collectively referred to as the “Group”) are focused on developing and commercializing therapies that address medical conditions with unmet medical needs including, in particular, oncology, autoimmune disorders and infectious diseases.

The Group’s principal operations and geographic markets are in the People’s Republic of China (“PRC”). The Group has a substantial presence in China (refers to mainland China hereinafter), Hong Kong, Macau and Taiwan (collectively referred to as the “Greater China”) and the United States. The accompanying consolidated financial statements include the financial statements of the Company and its subsidiaries.

As of December 31, 2020, the Group’s significant operating subsidiaries are as follows:


Name of company	Place of incorporation	Date of incorporation	Percentage of ownership	Principal activities

Zai Lab (Hong Kong) Limited	Hong Kong	April 29, 2013	100%	Operating company for business development and R&D activities and commercialization of innovative medicines and device
Zai Lab (Shanghai) Co., Ltd.	PRC	January 6, 2014	100%	Development and commercialization of innovative medicines and devices
Zai Lab (AUST) Pty., Ltd.	Australia	December 10, 2014	100%	Clinical trial activities
Zai Lab (Suzhou) Co., Ltd.	PRC	November 30, 2015	100%	Development and commercialization of innovative medicines
Zai Biopharmaceutical (Suzhou) Co., Ltd.	PRC	June 15, 2017	100%	Development and commercialization of innovative medicines
Zai Lab (US) LLC	U.S.	April 21, 2017	100%	Operating company for business development and R&D activities
Zai Lab International Trading (Shanghai) Co., Ltd.	PRC	November 6, 2019	100%	Commercialization of innovative medicines and devices
Zai Auto Immune (Hong Kong) Limited	Hong Kong	November 4, 2020	100%	Operating company for business development and R&D activities

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Summary of significant accounting policies

2.	Summary of significant accounting policies

(a) Basis of presentation

The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). Significant accounting policies followed by the Group in the preparation of the accompanying consolidated financial statements are summarized below.

(b) Principles of consolidation

The consolidated financial statements include the financial statements of the Company and its subsidiaries. All intercompany transactions and balances among the Group and its subsidiaries are eliminated upon consolidation.

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the period. Areas where management uses subjective judgment include, but are not limited to, estimating the useful lives of long-lived assets, estimating the current expected credit losses for financial assets, assessing the impairment of long-lived assets, discount rate of operating lease liabilities, revenue recognition, allocation of the research and development service expenses to the appropriate financial reporting period based on the progress of the research and development projects, share-based compensation expenses, recoverability of deferred tax assets and the fair value of the financial instruments. Management bases the estimates on historical experience and various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ from these estimates.

(d) Foreign currency translation

The functional currency of Zai Lab Limited, Zai Lab (Hong Kong) Limited, Zai Lab (US) LLC and Zai Auto Immune (Hong Kong) Limited are the United States dollar (“$”). The Group’s PRC subsidiaries determined their functional currency to be Chinese Renminbi (“RMB”). The Group’s Australia subsidiary determined its functional currency to be Australian dollar (“A$”). The determination of the respective functional currency is based on the criteria of Accounting Standard Codification (“ASC”) 830,

Foreign Currency Matters

. The Group uses the United States dollar as its reporting currency.

Assets and liabilities are translated from each entity’s functional currency to the reporting currency at the exchange rate on the balance sheet date. Equity amounts are translated at historical exchange rates, and expenses, gains and losses are translated using the average rate for the year. Translation adjustments are reported as cumulative translation adjustments and are shown as a separate component of other comprehensive loss in the consolidated statements of changes in shareholders’ equity and comprehensive loss.

Monetary assets and liabilities denominated in currencies other than the applicable functional currencies are translated into the functional currencies at the prevailing rates of exchange at the balance sheet date.

Non-monetary

assets and liabilities are translated into the applicable functional currencies at historical exchange

rates. Transactions in currencies other than the applicable functional currencies during the year are converted into the functional currencies at the applicable rates of exchange prevailing at the transaction dates. Transaction gains and losses are recognized in the consolidated statements of operations.

(e) Cash, cash equivalents and restricted cash

Cash and cash equivalents

The Group considers all highly liquid investments purchased with original maturities of three months or less to be cash equivalents. Cash and cash equivalents consist primarily of cash on hand, demand deposits and highly liquid investments with maturity of less than three months and are stated at cost plus interests earned, which approximates fair value.

Restricted cash

Restricted cash mainly consists of the bank deposits held as collateral for issuance of letters of credit.

(f) Short-term investments

Short-term investments are time deposits with original maturities more than three months. Short-term investments are stated at cost, which approximates fair value. Interest earned is included in interest income.

(g) Accounts receivable

From January 1, 2020, the Group adopted the ASU

2016-13,

Credit Losses, Measurement of Credit Losses on Financial Instruments

. Accounts receivable are recorded at the amounts due from customers and net of allowances for credit losses. The allowance for credit losses reflects the Group’s current estimate of credit losses expected to be incurred over the life of the receivables. The Group considers various factors in establishing, monitoring, and adjusting its allowance for credit losses including the aging of receivables and aging trends, customer creditworthiness and specific exposures related to particular customers. The Group also monitors other risk factors and forward-looking information, such as country specific risks and economic factors that may affect a customer’s ability to pay in establishing and adjusting its allowance for credit losses. Accounts receivable are written off when deemed uncollectible.

(h) Inventories

Inventories are stated at the lower of cost or net realizable value, with cost determined on a weighted average basis. The Group periodically reviews the composition of inventory and shelf life of inventory in order to identify obsolete, slow-moving or otherwise

non-saleable

items. The Group will record a write-down to its net realizable value in cost of sales in the period that the decline in value is first identified. Nil and $29 inventory

write-downs were

recorded as of December 31, 2019 and 2020, respectively.

(i) Investments in equity investees

The Group uses the equity method to account for an equity investment over which it has significant influence but does not own a majority equity interest or otherwise control. The Group records equity method adjustments in

share of earnings and losses. Equity method adjustments include the Group’s proportionate share of investee income or loss, adjustments to recognize certain differences between the Group’s carrying value and its equity in net assets of the investee at the date of investment, impairments, and other adjustments required by the equity method. Dividends received are recorded as a reduction of carrying amount of the investment. Cumulative distributions that do not exceed the Group’s cumulative equity in earnings of the investee are considered as a return on investment and classified as cash inflows from operating activities. Cumulative distributions in excess of the Group’s cumulative equity in the investee’s earnings are considered as a return of investment and classified as cash inflows from investing activities.

The Group is required to perform an impairment assessment of its investments whenever events or changes in business circumstances indicate that the carrying value of the investment may not be fully recoverable. An impairment loss is recorded when there has been a loss in value of the investment that is other than temporary. No impairment was recorded for the years ended December 31, 2018, 2019 and 2020.

(j) Prepayments for equipment

The prepayments for equipment purchase are recorded in long term prepayments considering the prepayments are all related to property and equipment.

(k) Property and equipment

Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets as follows:


		Useful life
Office equipment		3 years
Electronic equipment		1.25-3 years
Vehicles		4 years
Laboratory equipment		5 years
Manufacturing equipment		10 years
Leasehold improvements		lesser of useful life or lease term

Construction in progress represents property and equipment under construction and pending installation and is stated at cost less impairment losses if any.

(l) Lease

From January 1, 2019, the Group adopted the ASC Topic 842,

Leases

(“ASC 842”). The Group adopted the new guidance using the modified retrospective transition approach by applying the new standard to all leases existing at the date of initial application and not restating comparative periods.

The Group determines if an arrangement is a lease at inception. The Group classifies the lease as a finance lease if it meets certain criteria or as an operating lease when it does not. The Group has lease agreements with lease and

non-lease

components, which the Group has elected to account for the components as a single lease component. The Group leases facilities for office, research and development center, and manufacturing facilities in China, Hong Kong, and the United States, which are all classified as operating leases with fixed lease payments, or minimum payments, as contractually stated in the lease agreements. The Group’s leases do not contain any material residual value guarantees or material restrictive covenants.

At the commencement date of a lease, the Group recognizes a lease liability for future fixed lease payments and a

right-of-use

(“ROU”) asset representing the right to use the underlying asset during the lease term. The lease liability is initially measured as the present value of the future fixed lease payments that will be made over the lease term. The lease term includes periods for which it’s reasonably certain that the renewal options will be exercised and periods for which it’s reasonably certain that the termination options will not be exercised. The future fixed lease payments are discounted using the rate implicit in the lease, if available, or the incremental borrowing rate (“IBR”). Upon adoption of ASU

2016-02,

the Group elected to use the remaining lease term as of January 1, 2019 in the Group’s estimation of the applicable discount rate for leases that were in place at adoption. For the initial measurement of the lease liability for leases commencing after January 1, 2019, the Group uses the discount rate as of the commencement date of the lease, incorporating the entire lease term. Additionally, the Group elected not to recognize leases with lease terms of 12 months or less at the commencement date in the consolidated balance sheets.

The ROU asset is measured at the amount of the lease liability with adjustments, if applicable, for lease prepayments made prior to or at lease commencement, initial direct costs incurred by the Group and lease incentives. Under ASC 842, land use rights agreements are also considered to be operating lease contracts. The Group will evaluate the carrying value of ROU assets if there are indicators of impairment and review the recoverability of the related asset group. If the carrying value of the asset group is determined to not be recoverable and is in excess of the estimated fair value, the Group will record an impairment loss in other expenses in the consolidated statements of operations. ROU assets for operating leases are included in operating lease

right-of-use

assets in the consolidated balance sheets.

Operating leases are included in operating lease

right-of-use

assets and operating lease liabilities in the consolidated balance sheets. Operating lease liabilities that become due within one year of the balance sheet date are classified as current operating lease liabilities.

Lease expense is recognized on a straight-line basis over the lease term.

(m) Land use rights

All land in the PRC is owned by the PRC government. The PRC government may sell land use rights for a specified period of time. The purchase price of land use rights represents the operating lease prepayments for the rights to use the land in the PRC under ASC 842 and is recorded as land use rights on the balance sheet, which is amortized over the remaining lease term.

In 2019, the Group acquired land use rights from the local Bureau of Land and Resources in Suzhou for the purpose of constructing and operating the research center and biologics manufacturing facility in Suzhou. The land use rights are being amortized over the respective lease terms, which are 30 years.

(n) Long term deposits

Long term deposits represent amounts paid in connection with the Group’s long-term lease agreements.

(o) Value added tax recoverable

Value added tax recoverable represent amounts paid by the Group for purchases. The amounts were recorded as long-term assets considering they are expected to be deducted from future value added tax payables arising on the Group’s future revenues.

(p) Intangible assets

Intangible assets mainly consist of externally purchased software which are amortized over one to five years on a straight-line basis. Amortization expenses for the years ended December 31, 2018, 2019 and 2020 were $15, $305 and $307, respectively. Amortization expenses of the Group’s intangible assets are expected to be approximately $402, $399, $386, $270 and $55 for the years ended December 31, 2021, 2022, 2023, 2024, and 2025 and thereafter, respectively.

(q) Impairment of long-lived assets

Long-lived assets are reviewed for impairment in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. Long-lived assets are reported at the lower of carrying amount or fair value less cost to sell. For the years ended December 31, 2018, 2019 and 2020, there was no impairment of the value of the Group’s long-lived assets.

(r) Fair value measurements

The Group applies ASC topic 820 (“ASC 820”),

Fair Value Measurements and Disclosures

, in measuring fair value. ASC 820 defines fair value, establishes a framework for measuring fair value and requires disclosures to be provided on fair value measurement.

ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2 — Include other inputs that are directly or indirectly observable in the marketplace.

Level 3 — Unobservable inputs which are supported by little or no market activity.

ASC 820 describes three main approaches

to measuring the fair value of assets and liabilities: (i) market approach; (ii) income approach; and (iii) cost approach. The market approach uses prices and other relevant information generated from market transactions involving identical or comparable assets or liabilities. The income approach uses valuation techniques to convert future amounts to a single present value amount. The measurement is based on the value indicated by current market expectations about those future amounts. The cost approach is based on the amount that would currently be required to replace an asset.

Financial instruments of the Group primarily include cash, cash equivalents and restricted cash, short-term investments, accounts receivable, prepayments and other current assets, short-term borrowings, accounts payable and other current liabilities. As of December 31, 2019 and 2020, the carrying values of cash and cash equivalents, short-term investments, accounts receivable, prepayments and other current assets, short-term borrowings, accounts payable and other current liabilities approximated their fair values due to the short-term maturity of these instruments, and the carrying value of restricted cash approximates its fair value based on the nature and the assessment of the ability to recover these amounts.

(s) Revenue recognition

In 2018, the Group adopted of ASC Topic 606 (“ASC 606”),

Revenue from Contracts with Customers,

in recognition of revenue

Under ASC 606, the Group recognizes revenue when its customer obtains control of promised goods or services, in an a

ount that reflects the consideration expected to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Group determines are within the scope of ASC 606, the Group performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Group satisfies a performance obligation. The Group only applies the five-step model to contracts when it is probable that the Group will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. Once a contract is determined to be within the scope of ASC 606 at contract inception, the Group reviews the contract to determine which performance obligations it must deliver and which of these performance obligations are distinct. The Group recognizes as revenue the amount of the transaction price that is allocated to each performance obligation when that performance obligation is satisfied or as it is satisfied.

The Group’s revenue is all from product sales. The Group recognizes revenue from product sales when the Group has satisfied the performance obligation by transferring control of the product to the customers. Control of the product generally transfers to the customers when the delivery is made and when title and risk of loss transfers to the consumers. Cost of sales mainly consists of the acquisition cost of products and royalty fee.

The Group has applied the practical expedients under ASC 606 with regard to assessment of financing component and concluded that there is no significant financing component given that the period between delivery of goods and payment is generally one year or less. The Group started to generate product sales revenue since 2018. For the year ended December 31, 2019 and 2020, the Group’s product revenues were mainly generated from the sale of ZEJULA

(niraparib) and Optune (Tumor Treating Fields) to customers.

In China, the Group sells the products to distributors, who ultimately sell the products to health care providers. Based on the nature of the arrangements, the performance obligations are satisfied upon the products delivery to distributors. Rebates are offered to distributors, consistent with pharmaceutical industry practices. The estimated amount of unpaid or unbilled rebates are recorded as a reduction of revenue if any. Estimated rebates are determined based on contracted rates, sales volumes and distributor inventories. The Group regularly reviews the information related to these estimates and adjusts the amount accordingly.

In Hong Kong, the Group sells the products to customers, which are typically healthcare providers such as oncology centers. The Group utilizes a third party for warehousing services. Based on the nature of the arrangement, the Group has determined that it is a principal in the transaction since the Group is primarily responsible for fulfilling the promise to provide the products to the customers, maintains inventory risk until delivery to the customers and has latitude in establishing the price. Revenue was recognized at the amount to which the Group expected to be entitled in exchange for the sale of the products, which is the sales price agreed with the customers. Consideration paid to the third party is recognized in operating expenses.

The Group didn’t recognize any contract assets and contract liabilities as of December 31, 2019 and 2020.

(t) Research and development expenses

Elements of research and development expenses primarily include (i) payroll and other related costs of personnel engaged in research and development activities;

(ii) in-licensed

patent rights fees of exclusive development rights of products granted to the Group; (iii) costs related to

pre-clinical

testing of the Group’s technologies under development and clinical trials such as payments to contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), investigators and clinical trial sites that conduct our clinical studies; (iv) costs to develop the product candidates, including raw materials and supplies, product testing, depreciation, and facility related expenses; and (v) other research and development expenses. Research and development expenses are charged to expense as incurred when these expenditures relate to the Group’s research and development services and have no alternative future uses.

The Group has acquired rights to develop and commercialize product candidates. Upfront payments that relate to the acquisition of a new product compound, as well as

pre-commercial

milestone payments, are immediately expensed as acquired

in-process

research and development in the period in which they are incurred, provided that the new product compound did not also include processes or activities that would constitute a “business” as defined under U.S. GAAP, and the product candidate has

not achieved regulatory approval for marketing and, absent obtaining such approval, has no established alternative future use. Milestone payments made to third parties subsequent to regulatory approval which meet the capitalization criteria would be capitalized as intangible assets and amortized over the estimated remaining useful life of the related product. If the conditions enabling capitalization of development costs as an asset have not yet been met, all development expenditures are recognized in profit or loss when incurred.

(u) Deferred income

Deferred income mainly consists of deferred income from government grants, American Depositary Receipts (the “ADR”) Program Agreement with ADR depositary bank (the “DB”) in July 2017 and the upfront payments received from Huizheng (Shanghai) Pharmaceutical Technology Co., Ltd. (“Hanhui”).

Government grants consist of cash subsidies received by the Group’s subsidiaries in the PRC from local governments. Grants received as incentives for conducting business in certain local districts with no performance obligation or other restriction as to the use are recognized when cash is received. Cash grants of $1,332, $2,151 and $7,289 were included in other income for the years ended December 31, 2018, 2019 and 2020, respectively. Grants received with government specified performance obligations are recognized when all the obligations have been fulfilled. If such obligations are not satisfied, the Group may be required to refund the subsidy. Cash grants of $2,023 and $2,519 were recorded in deferred income as of December 31, 2019 and 2020 respectively, which will be recognized when the government specified performance obligation is satisfied.

According to the ADR program agreement, the Group has the right to receive reimbursements for using DB’s services, subject to the compliance by the Group with the terms of the agreement. The Group performed a detail assessment of the requirements and recognizes the reimbursements it expects to be entitled to over the five-year contract term as other income. For the years ended December 31, 2018, 2019 and 2020, $312, $312 and $312 were recorded in other income, respectively. $858 and $546 were recorded in deferred income as of December 31, 2019 and 2020, respectively.

In March 2020, the Group entered into an exclusive promotion agreement with Hanhui. Under the terms of the agreement, the Group will leverage Hanhui’s existing infrastructure to optimize an anticipated future commercial

launch of omadacycline in China given that omadacycline is a broad-spectrum antibiotic in both the hospital and community care facilities. In exchange for the exclusive promotion rights in China, Hanhui has agreed to pay the Group a non-creditable, upfront payment in the amount of

RMB230,000,

which RMB90,000 was received in April 2020. The Group assessed and determined that the income recognition criteria was not met and recorded the upfront payment as deferred income. As of December 31, 2020, a total amount of RMB

90,000

($13,793) was recorded in deferred income.

(v) Comprehensive loss

Comprehensive loss is defined as the changes in equity of the Group during a period from transactions and o

her events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Among other disclosures, ASC 220,

Comprehensive Income

, requires that all items that are required to be recognized under current accounting standards as components of comprehensive loss be reported in a financial statement that is displayed with the same prominence as other financial statements. For each of the periods presented, the Group’s comprehensive loss includes net loss and foreign currency translation adjustments, which are presented in the consolidated statements of comprehensive loss.

(w) Share-based compensation

The Group grants share options and

non-vested

restricted shares to eligible employees, management and directors and accounts for these share-based awards in accordance with ASC 718,

Compensation-Stock Compensation.

Employees’ share-based awards are measured at the grant date fair value of the awards and recognized as expenses (i) immediately at grant date if no vesting conditions are required; or (ii) using graded vesting method over the requisite service period, which is the vesting period.

All transactions in which goods or services are received in exchange for equity instruments are accounted for based on the fair value of the consideration received or the fair value of the equity instrument issued, whichever is more reliably measurable.

To the extent the required vesting conditions are not met resulting in the forfeiture of the share-based awards, previously recognized compensation expense relating to those awards are reversed.

The Group determined the fair value of the stock options granted to employees using the Black-Scholes option valuation model.

Awards Granted to

Non-Employees

The Group grants share options to eligible

Non-Employees

and accounts for these share-based awards in accordance with ASC 718,

Compensation-Stock Compensation.

Non-Employees’

share-based awards are measured at the grant date fair value of the awards and recognized as expenses (i) immediately at grant date if no vesting conditions are required; or (ii) using graded vesting method over the requisite service period, which is the vesting period. All transactions in which goods or services are received in exchange for equity instruments are accounted for based on the fair value of the consideration received or the fair value of the equity instrument

issued, whichever is more reliably measurable. To the extent the required vesting conditions are not met resulting in the forfeiture of the share-based awards, previously recognized compensation expense relating to those awards are reversed. The Group determined the fair value of the stock options granted to

Non-Employees

using the Black-Scholes option valuation model.

(x) Income taxes

Income tax expense includes (i) deferred tax expense, which generally represents the net change in the deferred tax asset or liability balance during the year plus any change in valuation allowances; (ii) current tax expense, which represents the amount of tax currently payable to or receivable from a taxing authority; and

(iii) non-current

tax expense, which represents the increases and decreases in amounts related to uncertain tax positions from prior periods and not settled with cash or other tax attributes.

The Group recognizes deferred tax assets and liabilities for temporary differences between the financial statement and income tax bases of assets and liabilities, which are measured using enacted tax rates and laws that will be in effect when the differences are expected to reverse. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized.

The Group evaluates its uncertain tax positions using the provisions of ASC 740,

Income Taxes

, which requires that realization of an uncertain income tax position be recognized in the financial statements. The benefit to be recorded in the financial statements is the amount most likely to be realized assuming a review by tax authorities having all relevant information and applying current conventions. It is the Group’s policy to recognize interest and penalties related to unrecognized tax benefits, if any, as a component of income tax expense. No unrecognized tax benefits and related interest and penalties were recorded in any of the periods presented.

(y) Earnings (loss) per share

Basic earnings (loss) per ordinary share is computed by dividing net income (loss) attributable to ordinary shareholders by weighted average number of ordinary shares outstanding during the period.

Diluted earnings (loss) per ordinary share reflects the potential dilution that could occur if securities were exercised or converted into ordinary shares. The Group had stock options and

non-vested

restricted shares, which could potentially dilute basic earnings (loss) per share in the future. To calculate the number of shares for diluted earnings (loss) per share, the effect of the stock options and

non-vested

restricted shares is computed using the treasury stock method. The computation of diluted earnings (loss) per share does not assume exercise or conversion of securities that would have an anti-dilutive effect.

(z) Segment information

In accordance with ASC 280,

Segment Reportin

g, the Group’s chief operating decision maker, the Chief Executive Officer, reviews the consolidated results when making decisions about allocating resources and assessing performance of the Group as a whole and hence, the Group has only one reportable segment. The Group does not distinguish between markets or segments for the purpose of internal reporting. As the Group’s long-lived assets are substantially located in and derived from China, no geographical segments are presented.

(aa) Concentration of risks

Concentration of customers

The following customers accounted for 10% or more of revenue for the years en

ed December 31, 2018, 2019 and 2020:


	Year ended December 31,
	2018		2019		2020
	$		$		$
A		51		5,397		*
B		34		*		*
C		14		*		*
D		*		4,682		*
E		*		*		15,774

*	Represents less than 10% of revenue for the years ended December 31, 2018, 2019 and 2020.

Concentration of suppliers

The following suppliers accounted for 10% or more of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020:

Year ended December 31,

2018

2019

2020

25,515

14,664

27,966

18,362

33,564

26,710

*	Represents less than 10% of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020.

Concentration of credit risk

Financial instruments that are potentially subject to significant concentration of credit risk consist of cash and cash equivalents, and short-term investments. The carrying amounts of cash and cash equivalents and short-term investments represent the maximum amount of loss due to credit risk. As of December 31, 2019 and 2020, all of the Group’s cash and cash equivalents and short-term investments were held by major financial institutions located in the PRC and international financial institutions outside of the PRC which management believes are of high credit quality and continually monitors the credit worthiness of these financial institutions.

Foreign currency risk

RMB is not a freely convertible currency. The State Administration of Foreign Exchange, under the authority of the People’s Bank of China, controls the conversion of RMB into foreign currencies. The value of RMB is

subject to changes in central government policies and to international economic and political developments affecting supply and demand in the China Foreign Exchange Trading System market. The cash and cash equivalents of the Group included aggregated amounts of RMB47,168 and RMB155,934, which were denominated in RMB, as of December 31, 2019 and 2020, respectively, representing 9% and 5% of the cash and cash equivalents as of December 31, 2019 and 2020, respectively.

(ab) Recent accounting pronouncements

Adopted Accounting Standards

In June 2016, the FASB issued ASU

2016-13,

Credit Losses, Measurement of Credit Losses on Financial Instruments

, which has subsequently been amended by ASU

2018-19,

ASU

2019-04,

ASU

2019-05,

ASU

2019-10,

ASU

2019-11

and ASU

2020-03.

This ASU significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The standard has replaced incurred loss approach with an expected loss model for instruments measured at amortized cost. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The standards are to be applied using a modified retrospective approach and are effective for interim periods and fiscal years beginning after December 15, 2019, with early adoption permitted.

The Group adopted the standard on January 1, 2020. Based on the composition of the Group’s trade receivables and investment portfolio, the adoption of this standard did not have a material impact on the Group’s financial position or results of operations upon adoption. The Group has updated its accounting policy for accounts receivable and is providing additional disclosure about its allowance for credit losses, as required by the standard, upon adoption. The impact of other financial instrument is not material.

In August 2018, the FASB issued ASU

2018-13,

Fair Value Measurement (Topic 820):

Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement

. This guidance removes certain disclosure requirements related to the fair value hierarchy, modifies existing disclosure requirements related to measurement uncertainty and adds new disclosure requirements. The new disclosure requirements include disclosing the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. Certain disclosures required by this guidance must be applied on a retrospective basis and others on a prospective basis. The guidance is effective for interim periods and fiscal years beginning after December 15, 2019, with early adoption permitted. The Group adopted this standard on January 1, 2020. There was no impact to the Group’s financial position or results of operations upon adoption as the Group did not have any financial instruments that are measured as level 3.

In November 2018, the FASB issued ASU

2018-18,

Collaborative Arrangements (Topic 808)

: Clarifying the Interaction between Topic 808 and Topic 606. This update clarifies that certain transactions between participants in a collaborative arrangement should be accounted for under ASC 606 when the counterparty is a customer and precludes an entity from presenting consideration from a transaction in a collaborative arrangement as revenue from contracts with customers if the counterparty is not a customer for that transaction. The update is effective in fiscal years beginning after December 15, 2019, and interim periods therein, and early adoption is permitted for entities that have adopted ASC 606. The Group adopted this standard on January 1, 2020. There was no material impact to the Group’s financial position or results of operations upon adoption.

Future Adoption of Accounting Standards

In December 2019, the FASB issued ASU

2019-12,

Income Taxes (Topic 740):

Simplifying the Accounting for Income Taxes

. This update simplifies the accounting for income taxes as part of the FASB’s overall initiative to reduce complexity in accounting standards. The amendments include removal of certain exceptions to the general principles of ASC 740,

Income taxes

, and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The update is effective in fiscal years beginning after Dec

mber 15, 2020, and interim periods therein, and early adoption is permitted. Certain amendments in this update should be applied retrospectively or modified retrospectively, all other amendments should be applied prospectively. The Group is currently evaluating the impact on its financial statements of adopting this guidance.

Cash and ash equivalents

12 Months Ended

Dec. 31, 2020

Cash and Cash Equivalents [Abstract]

Cash and cash equivalents

3.	Cash and cash equivalents


	As of December 31,
	2019		2020
	$		$
Cash at bank and in hand		75,111		441,283
Cash equivalents		821		833

		75,932		442,116

Denominated in:
US$		62,478		297,813
RMB (note (i))		6,761		23,898
Hong Kong dollar (“HK$”)		5,948		119,695
Australian dollar (“A$”)		745		710

		75,932		442,116

Note:

(i)	Certain cash and bank balances denominated in RMB were deposited with banks in the PRC. The conversion of these RMB denominated balances into foreign currencies is subject to the rules and regulations of foreign exchange control promulgated by the PRC government.

Restricted cash, non-current

12 Months Ended

Dec. 31, 2020

Restricted Cash [Abstract]

Restricted cash, non-current

4.	Restricted cash, non-current

The Group’s restricted cash balance of $510 and $743 as of December 31, 2019 and 2020 was long-term bank deposits held as collateral for issuance of letters of credit. These deposits will be released when the related letters of credit are settled by the Group.

Short-term investments

12 Months Ended

Dec. 31, 2020

Short-term investments

Short-term investments

5.	Short-term investments

Short-term investments are primarily comprised of

time deposits with original maturities between three months and one year. For the years ended December 31, 2018, 2019 and 2020, the Group recorded the interest income of $2,359, $7,778 and $4,860

, respectively, from the short-term investments in the consolidated statements of operations.

As of December 31, 2020, the Group’s short-term investments consisted entirely of short-term held to maturity debt instruments with

high credit ratings,

which were determined to have

risk of expected credit loss. Accordingly,

allowance for credit loss was recorded as of December 31, 2019 and 2020.

Accounts receivable

12 Months Ended

Dec. 31, 2020

Receivables [Abstract]

Accounts receivable

6.	Accounts receivable

The roll-forward of the allowance for credit losses related to accounts receivable for the year ended December 31, 2020 consists of the following activity:


	Allowance for Credit Losses
	$
Balance as of December 31, 2019		—
Current period provision for expected credit losses		1
Amounts written-off		—
Recoveries of amounts previously written-off		—

Balance as of December 31, 2020		1

The Group did not have any allowance for credit losses for the years ended December 31, 2018 and 2019.

Inventories

12 Months Ended

Dec. 31, 2020

Inventories

Inventories

7.	Inventories

The Group’s inventory balance of $6,005 and $13,144 as of December 31, 2019 and 2020,

respectively, mainly consisted of finished goods purchased from Tesaro Inc., now GlaxoSmithK

ine (GSK) and NovoCure Limited (“NovoCure”) for distribution in Hong Kong, as well as finish goods and certain raw materials for ZEJULA commercialization in China.


	As of December 31,
	2019		2020
	$		$
Finished goods		593		3,041
Raw materials		5,412		10,103

Inventories		6,005		13,144

The Group write-down inventory for any excess or obsolete inventories or when the Group believe that the net realizable value of inventories is less than the carrying value. During the years ended December 31, 2018, 2019 and 2020, the Group recorded write-downs of $

Nil

$Nil and $

, respectively, in cost of revenues.

Investments in Equity Investees

12 Months Ended

Dec. 31, 2020

Investments in equity investees

Investments in equity investees

8.	Investments in equity investees

In June 2017, the Group entered into an agreement with three third-parties to launch JING Medicine Technology (Shanghai) Ltd. (“JING”), an entity which provides services for

product

discovery and development, consultation and transfer of pharmaceutical technology. The capital contribution by the Group was RMB26,250 in cash,

representing 20% of the equity interest of JING, which was paid by the Group in 2017 and 2018. The Group accounts for this investment using the equity method of accounting due to the fact that the Group can exercise significant influence on the investee and recorded its share of loss in this investee of $587, $752 and $1,119 for the years ended December 31, 2018, 2019 and 2020, respectively.

Property and Equipment, net

12 Months Ended

Dec. 31, 2020

Property and equipment, net

Property and equipment, net

9.	Property and equipment, net

Property and equipment consist of the following:


	As of December 31,
	2019			2020
	$			$
Office equipment		397			430
Electronic equipment		1,482			2,646
Vehicle		76			143
Laboratory equipment		5,854			11,933
Manufacturing equipment		11,049			12,198
Leasehold improvements		7,528			9,641
Construction in progress		428			2,423

		26,814			39,414
Less: accumulated depreciation		(5,461	)		(10,252	)

Property and equipment, net		21,353			29,162

Depreciation expenses for the years ended December 31, 2018, 2019 and 2020 were $1,634, $3,372 and $4,324, respectively.

Lease

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Lease

10.

Lease

The Group leases facilities for office, research and development and manufacturing facilities in China, Hong Kong,

and the United States.

Lease terms vary based on the nature of operations and the market dynamics, however, all leased facilities are classified as operating leases with remaining lease terms between

one

and seven years.

Total lease expense related to short-term leases was insignificant for the year ended December 31, 2019 and 2020.

Supplemental information related to leases was as follows:


	Year ended December 31,
	2019		2020
	$		$
Operating fixed lease cost		3,245		4,539

Supplemental cash flow information related to leases was as follows:


	Year ended December 31,
	2019		2020
	$		$
Cash paid for amounts included in measurement of lease liabilities		2,778		4,056
Non-cash operating lease liabilities arising from obtaining operating right-of-use assets		10,876		6,393

The maturities of lease liabilities in accordance with

Leases (Topic 842)

in each of the next five years and thereafter as of December 31, 2020 were as follows:


	Year ended December 31
	$
2021		5,434
2022		4,362
2023		2,401
2024		2,238
2025		2,192
Thereafter		2,610
Total lease payments		19,237
Less: imputed interest		(639	)

Present value of minimum operating lease payments		18,598

Weighted-average remaining lease terms and discount rates are as follows:


	Year ended December 31,
	2019			2020
Weighted-average remaining lease term		4.4 years			5.0 years
Weighted-average discount rate		3.1	%		2.3	%

Revenue

12 Months Ended

Dec. 31, 2020

Revenue

Revenue

11.

Revenue

The Group’s revenue is primarily derived from the sale of ZEJULA and Optune in China and Hong Kong. The table below presents the Group’s net product sales for the years ended December 31, 2018, 2019 and 2020.


	Year ended December 31,
	2018		2019		2020
	$		$		$
Product revenue — gross		129		12,985		57,355
Less: Rebate and sales return		—		—		(8,397	)

Product revenue — net		129		12,985		48,958

Sales rebates are offered to distributors in China and the amounts are recorded as a reduction of revenue. Estimated rebates are determined based on contracted rates, sales volumes and distributor inventories.

The following table disaggregates net revenue by product for the years ended December 31, 2018, 2019 and 2020:


	Year ended December 31,
	2018		2019		2020
	$		$		$
ZEJULA		129		6,625		32,138
Optune		—		6,360		16,418
Others		—		—		402

Total product revenue — net		129		12,985		48,958

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130550-203045

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

+ Details

Income Tax

12 Months Ended

Dec. 31, 2020

Income tax

Income tax

12.	Income Tax

Cayman Islands (“Cayman”)

Zai Lab Limited, ZLIP Holding Limited, Zai Auto Immune Limited, and Zai Anti Infectives Limited are incorporated in the Cayman Islands. Under the current laws of the Cayman Islands, Zai Lab Limited, ZLIP Holding Limited, Zai Auto Immune Limited, and Zai Anti Infectives Limited are not subject to tax on income or capital gain. Additionally, the Cayman Islands does not impose a withholding tax on payments of dividends to shareholders.

British Virgin Islands Taxation (“BVI”)

ZL Capital Limited is incorporated in the British Virgin Islands. Under the current laws of the British Virgin Islands, ZL Capital Limited is not subject to income tax.

Australia (“AUST”)

Zai Lab (AUST) Pty., Ltd. is incorporated in Australia and is subject to corporate income tax at a rate of 30%. Zai Lab (AUST) Pty., Ltd. has no taxable income for all periods presented, therefore, no provision for income taxes is required.

United States. (“U.S.”)

Zai Lab (US) LLC is incorporated

in U.S. and is subject to U.S. federal corporate income tax at a rate of 21%. Zai Lab (US) LLC is also subject to state income tax in Delaware. Zai Lab (US) LLC has no taxable income for all periods presented, therefore, no provision for income taxes is required.

Hong Kong (“HK”)

Zai Lab (Hong Kong) Limited, ZL China Holding Two Limited, Zai Auto Immune (Hong Kong) Limited, and Zai Anti Infectives (Hong Kong) Limited are incorporated in Hong Kong. Companies registered in Hong Kong

are subject to Hong Kong profits tax on the taxable income as reported in their respective statutory financial statements adjusted in accordance with relevant Hong Kong tax laws. Under the

two-tiered

profits tax rates regime in Hong Kong, the first HK$2 million of profits of the qualifying group entity will be taxed at 8.25%, and profits above HK$2 million will be taxed at 16.5%. For the years ended December 31, 2018, 2019 and 2020, Zai Lab (Hong Kong) Limited, ZL China Holding Two Limited, Zai Auto Immune (Hong Kong) Limited, and Zai Anti Infectives (Hong Kong) Limited did not make any provisions for Hong Kong profit tax as there were no assessable profits derived from or earned in Hong Kong for any of the periods presented. Under the Hong Kong tax law, Zai Lab (Hong Kong) Limited, ZL China Holding Two Limited, Zai Auto Immune (Hong Kong) Limited, and Zai Anti Infectives (Hong Kong) Limited are exempted from income tax on its foreign-derived income and there are no withholding taxes in Hong Kong on remittance of dividends.

PRC

Under PRC’s Enterprise Income Tax Law (“EIT Law”), the statutory income tax rate is 25%, and the EIT rate

will

be reduced to 15% for state-encouraged High and New Technology Enterprises (“HNTE”). Zai Lab (Shanghai) Co., Ltd., first obtained a HNTE certificate in 2018 and began to enjoy the preferential tax rate of 15% from 2018 to 2020. Zai Lab International Trading (Shanghai) Co., Ltd., Zai Lab (Suzhou) Co., Ltd., Zai Biopharmaceutical (Suzhou) Co., Ltd., and Zai Lab Trading (Suzhou) Co., Ltd. are subject to the statutory rate of 25%.

No provision for income taxes has been required to be accrued because the Company and all of its subsidiaries are in cumulative loss positions for all the periods presented.

Loss (income) before income taxes consists of:


	Year ended December 31,
	2018		2019			2020
	$		$			$
Cayman		1,218		(3,241	)		2,612
BVI		2		2			3
PRC		127,711		185,239			220,813
HK		7,778		3,271			20,022
US		2,351		9,786			24,616
AUST		15		14			839

		139,075		195,071			268,905

Reconciliations of the differences between the PRC statutory income tax rate and the Group’s effective income tax rate for the years ended December 31, 2018, 2019 and 2020 are as follows:


	Year ended December 31,
	2018			2019			2020
Statutory income tax rate		25	%		25	%		25	%
Share-based compensations		(1.93	%)		(1.51	%)		(1.36	%)
Non-deductible expenses		(0.38	%)		(0.39	%)		(1.17	%)
Prior year tax filing adjustment		1.55	%		1.93	%		1.78	%
Effect of different tax rate of subsidiary operation in other jurisdictions		(0.76	%)		0.07	%		(1.04	%)
Preferential tax rate		—			(9.14	%)		(7.48	%)
Effect of change in tax rate		—			(9.15	%)		—
Changes in valuation allowance		(23.48	%)		(6.81	%)		(15.73	%)

Effective income tax rate		—			—			—

The principal components of the deferred tax assets and liabilities are as follows:


	Year ended December 31,
	2018			2019			2020
	$			$			$
Deferred tax assets:
Depreciation of property and equipment, net		15			57			84
Government grants		187			325			400
Deferred revenue		—			—			2,069
Public welfare donations		—			—			7,627
Net operating loss carry forwards		49,726			62,833			94,954
Less: valuation allowance		(49,928	)		(63,215	)		(105,134	)

Deferred tax assets, net		—			—			—

The Group considers positive and negative evidence to determine whether some portion or all of the deferred tax assets will be more likely than not realized. This assessment considers, among other matters, the nature, frequency and severity of recent losses and forecasts of future profitability. These assumptions require significant judgment and the forecasts of future taxable income are consistent with the plans and estimates the Group is using to manage the underlying businesses. Valuation allowances are established for deferred tax assets based on a more likely than not threshold. The Group’s ability to realize deferred tax assets depends on its ability to generate sufficient taxable income within the carry forward periods provided for in the tax law. In 2019 and 2020, the Group has determined that the deferred tax assets on temporary differences and net operating loss carry forwards are related to certain subsidiaries, for which the Group is not able to conclude that the future realization of those net operating loss carry forwards and other deferred tax assets are more likely than not. As such, it has fully provided valuation allowance for the deferred tax assets as of December 31, 2019 and 2020. Amounts of operating loss carry forwards were $204,693, $403,460 and $605,226 for the years ended December 31, 2018, 2019 and 2020, respectively, which are expected to expire from 2021 to 2030.

Movement of the valuation allowance is as follows:


	2019			2020
	$			$
Balance as of January 1,		(49,928	)		(63,215	)
Additions		(13,287	)		(41,919	)

Balance as of December 31,		(63,215	)		(105,134	)

Uncertainties exist with respect to how the current income tax law in the PRC applies to the Group’s overall operations, and more specifically, with regard to tax residency status. The EIT Law includes a provision specifying that legal entities organized outside of the PRC will be considered residents for Chinese income tax purposes if the place of effective management or control is within the PRC. The implementation rules to the EIT Law provide that

non-resident

legal entities will be considered PRC residents if substantial and overall management and control over the manufacturing and business operations, personnel, accounting and properties, occurs within the PRC. Despite the present uncertainties resulting from the limited PRC tax guidance on the issue, the Group does not believe that the legal entities organized outside of the PRC within the Group should be treated as residents for EIT Law purposes. If the PRC tax authorities subsequently determine that the Company and its subsidiaries registered outside the PRC should be deemed resident enterprises, the Company and its subsidiaries registered outside the PRC will be subject to the PRC income taxes, at a rate of 25%. The Group is not subject to any other uncertain tax position.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Short-term borrowings

12 Months Ended

Dec. 31, 2020

Short-term borrowings

Short-term borrowings

13.	Short-term borrowings

On June 25, 2018, Zai Lab (Suzhou) Co. Ltd. entered into a three-year facility agreement for RMB25,000 with a local commercial bank, and the outstanding borrowing under this agreement was nil as of December 31, 2020. The borrowing is guaranteed by Zai Lab (Shanghai) Co. Ltd., with an average interest rate of 4.785%. For the year ended December 31, 2020, Zai Lab (Suzhou) Co. Ltd. repaid the outstanding principal of RMB25, 000. For the year ended December 31, 2019, Zai Lab (Suzhou) Co. Ltd. drawn down an aggregate of RMB

30, 000

of this loan and repaid the outstanding principal of RMB 25,000. For the year ended December 31, 2018, Zai Lab (Suzhou) Co. Ltd. drawn down an aggregate of RMB

20, 000

of this loan.

On December 12, 2018, Zai Biopharmaceutical (Suzhou) Co. Ltd. entered into a three-year facility agreement for RMB40,000 with a local commercial bank, the outstanding borrowing under this agreement was nil as of December 31, 2020. The borrowing is guaranteed by Zai Lab (Shanghai) Co., Ltd., with average interest rate of 4.785%. For the year ended December 31, 2020, Zai Biopharmaceutical (Suzhou) Co. Ltd. repaid the outstanding principal RMB20, 000. For the year ended December 31, 2019, Zai Biopharmaceutical (Suzhou) Co. Ltd.

drew

down an aggregate of RMB

20, 000

of this loan and repaid the outstanding principal of RMB5,000. For the year ended December 31, 2018, Zai Biopharmaceutical (Suzhou) Co. Ltd.

drew

down an aggregate of RMB

5, 000

of this loan.

Other current liabilities

12 Months Ended

Dec. 31, 2020

Other current liabilities

Other current liabilities

14.	Other current liabilities

Other current liabilities consist of followings:


	As of December 31,
	2019		2020
	$		$
Payroll		9,590		13,694
Professional service fee		774		3,128
Payables for purchase of property and equipment		416		788
Payables for purchase of intangible assets		—		70
Accrued rebate to distributors		—		7,067
Others (note (i))		2,394		5,449

Total		13,174		30,196

Note:

(i)	Others are mainly payments from employees for exercising the share-based compensations, tax payables, and payables related to travel and business entertainment expenses and conference fee.

Loss per share

12 Months Ended

Dec. 31, 2020

Loss per share

Loss per share

15.	Loss per share

Basic and diluted net loss per share for each of the years presented are calculated as follow:


	For the years ended December 31,
	2018			2019			2020
Numerator:
Net loss attributable to ordinary shareholders		(139,075	)		(195,071	)		(268,905	)
Denominator:
Weighted average number of ordinary shares- basic and diluted		52,609,810			64,369,490			77,667,743

Net loss per share-basic and diluted		(2.64	)		(3.03	)		(3.46	)

As a result of the Group’s net loss for the three years ended December 31, 2018, 2019 and 2020, share options and

non-vested

restricted shares outstanding in the respective periods were excluded from the calculation of diluted loss per share as their inclusion would have been anti-dilutive.


	As of December 31,
	2018		2019		2020
Share options		8,761,735		9,122,980		8,755,920
Non-vested restricted shares		1,112,001		743,268		541,750

Related Party Transactions

12 Months Ended

Dec. 31, 2020

Related party transactions

Related party transactions

16.	Related party transactions

The table below sets forth the major related party and the relationship with the Group as of December 31, 2020:


Company Name		Relationship with the Group
MEDx (Suzhou) Translational Medicine Co., Ltd. (Formerly known as Qiagen (Suzhou) translational medicine Co., Ltd)		Significant influence held by Samantha (Ying) Du’s (Director, Chairwoman and Chief Executive Officer of the Company) immediate family

For the years ended December 31, 2018, 2019 and 2020, the Group incurred $126, $234 and $678 research and development expense with MEDx (Suzhou) Translational Medicine Co., Ltd. for

product

research and development services, respectively. All of the transactions are carried out with normal business terms and are on arms’ length basis.

Share-based compensation

12 Months Ended

Dec. 31, 2020

Share-based compensation

Share-based compensation

17.	Share-based compensation

Share options

On March 5, 2015, the Board of Directors of the Company approved an Equity Incentive Plan (the “2015 Plan”) which is administered by the Board of Directors. Under the 2015 Plan, the Board of Directors may grant options to purchase ordinary shares to management including officers, directors, employees and individual advisors who render services to the Group to purchase an aggregate of no more than 4,140,945 ordinary shares of the Group (“Option Pool”). Subsequently, the Board of Directors approved the increase in the Option Pool to 7,369,767 ordinary shares.

In connection with the completion of the initial public offering (the “IPO”), the Board of Directors has approved the 2017 Equity Incentive Plan (the “2017 Plan”) and all equity-based awards subsequent to the IPO would be granted under the 2017 Plan.

In 2018, the Group granted 2,759,750 share options to certain management and employees of the Group at the exercise price ranging from $17.60 to $24.58 per share under the 2017 Plan. These options granted have a contractual term of 10 years and generally vest over a five-year period, with 20% of the awards vesting beginning on the anniversary date one year after the grant date.

In 2019, the Group granted 1,067,385 share options to certain management, employees and individual advisors of the Group at the exercise price ranging from $27.23 to $41.59 per share under the 2017 Plan. These options granted have a contractual term of

ten years

and generally vest over a five or three-year period, with 20% or 33.3% of the awards vesting beginning on the anniversary date one year after the grant date.

In 2020, the Group granted 1,220,177 share options to certain management, employees and individual advisors of the Group at the exercise price ranging from $44.94 to $128.72 per share under the 2017 Plan. These options granted have a contractual term of ten years and generally vest over a five or three-year period, with 20% or 33.3% of the awards vesting beginning on the anniversary date one year after the grant date.

The following table presents the assumptions used to estimate the fair values of the share options granted in the years presented:


	2018	2019	2020

Risk-free rate of return	2.7%-3.2 %	1.6%-2.5 %	0.4%-0.8 %
Contractual life of option	10 years	10 years	10 years
Expected term	6.5 years	6 or 6.5 years	6 or 6.5 years
Estimated volatility rate	70%	70%	70%
Expected dividend yield	0%	0%	0%
Fair value of underlying ordinary shares	$17.60-$24.58	$27.23-$41.59	$44.94-$128.72

A summary of option activity under the 2015 Plan and 2017 Plan during the years ended December 31, 2018, 2019 and 2020 is presented below:


	Number of options			Weighted average exercise price		Weighted average remaining contractual term		Aggregate intrinsic value
				$		Years		$
Outstanding at January 1, 2018		6,548,377			1.28		8.06		130,669
Granted		2,759,750			21.15		—		—
Exercised		(256,065	)		0.76		—		—
Forfeited		(290,327	)		3.73		—		—
Outstanding at December 31, 2018		8,761,735			7.47		7.80		138,010
Granted		1,067,385			32.22		—		—
Exercised		(670,939	)		1.57		—		—
Forfeited		(35,201	)		25.99		—		—
Outstanding at December 31, 2019		9,122,980			10.73		7.16		281,562
Granted		1,220,177			63.98		—		—
Exercised		(899,361	)		7.41		—		—
Forfeited		(687,876	)		26.37		—		—
Outstanding at December 31, 2020		8,755,920			17.26		6.53		1,033,899

Vested and exercisable as of December 31, 2020		5,073,001			4.90		5.47		661,708
Vested or expected to vest as of December 31, 2020		8,755,920			17.26		6.53		1,033,899

The weighted-average grant-date fair value of the options granted in 2018, 2019 and 2020 were $14.03, $20.98 and $40.60 per share, respectively. The Group recorded compensation expense related to the options of $9,403, $14,925 and $18,695 for the years ended December 31, 2018, 2019 and 2020, respectively, which were classified in the accompanying consolidated statements of operations as follows:


	Year ended December 31,
	2018		2019		2020
	$		$		$
Selling, general and administrative		4,428		6,931		11,492
Research and development		4,975		7,994		7,203
Total		9,403		14,925		18,695

As of December 31, 2020, there was $71,909 of total unrecognized compensation expense related to unvested share options granted. That cost is expected to be recognized over a weighted-average period of 1.58 years.

Non-vested

restricted shares

In 2018, 62,500 ordinary shares were authorized for grant to the independent directors, respectively. The restricted shares shall vest and be released from the restrictions in full on the first anniversary from the date of the agreement.

Upon termination of an independent director’s service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

In 2018, 694,500 ordinary shares were authorized for grant to certain management.

One fifth

of the restricted shares shall vest and be released from the restrictions on each yearly anniversary from the date of the agreement. Upon termination of the certain management’s service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

In 2019, 50,000 ordinary shares were authorized for grant to the independent directors, respectively. The restricted shares shall vest and be released from the restrictions in full on the first anniversary from the date of the agreement.

Upon termination of an independent director’s service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

In 2019, 121,000 ordinary shares were authorized for grant to certain management.

One fifth

of the restricted shares will vest and be released from the restrictions on each yearly anniversary from the date of the agreement. Upon termination of the certain management’s service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

In 2020, 50,000 ordinary shares were authorized for grant to the independent directors. The restricted shares

will

vest and be released from the restrictions in full on the first anniversary from the date of the agreement. Upon termination of the independent directors’ service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

In 2020, 109,250 ordinary shares were authorized for grant to certain management. One fifth of the restricted shares

will

vest and be released from the restrictions on each yearly anniversary from the date of the agreement. Upon termination of the certain management’s service with the Group for any reason, any shares that are outstanding and not yet vested will be immediately forfeited.

The Group measured the fair value of the

non-vested

restricted shares as of respective grant dates and recognized the amount as compensation expense over the deemed service period using a graded vesting attribution model on a straight-line basis.

The following table summarized the Group’s

non-vested

restricted share activity in 2020:


	Numbers of non-vested restricted shares			Weighted average grant date fair value
				$
Non-vested as of January 1, 2019		1,112,001			15.13
Granted		171,000			27.55
Vested		(539,733	)		8.97
Non-vested as of December 31, 2019		743,268			22.45
Granted		159,250			74.55
Vested		(225,768	)		22.98
Forfeited		(135,000	)		23.20

Non-vested as of December 31, 2020		541,750			37.36

As of December 31, 2020, there was $16,335 of total unrecognized compensation expense related to

non-vested

restricted shares. The Group recorded compensation expense related to the restricted shares of $2,826, $5,366 and $6,135 for the years ended December 31, 2018, 2019 and 2020, respectively, which were classified in the accompanying consolidated statements of operations as follows:


	Year ended December 31,
	2018		2019		2020
	$		$		$
Selling, general and administrative		2,206		3,643		4,226
Research and development		620		1,723		1,909

Total		2,826		5,366		6,135

Accumulated Other Comprehensive (Loss) Income

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Accumulated Other Comprehensive (Loss) Income

18.	Accumulated other comprehensive income (loss)

The movement of accumulated other comprehensive income (loss) is as follows:


	Foreign currency translation adjustments
	$
Balance as of January 1, 2018		450
Other comprehensive income		2,212
Balance as of December 31, 2018		2,662
Other comprehensive income		1,958
Balance as of December 31, 2019		4,620
Other comprehensive loss		(19,144	)

Balance as of December 31, 2020		(14,524	)

Licenses and collaborative arrangement

12 Months Ended

Dec. 31, 2020

Licenses And Collaborative Arrangement [Abstract]

Licenses and collaborative arrangement

19.	Licenses and collaborative arrangement

The following is a description of the Group’s significant ongoing collaboration agreements for the years ended December 31, 2020.

License and collaboration agreement with GSK

In September 2016,

the Group entered into a collaboration, development and license agreement with Tesaro, Inc, a company later acquired by GSK, pursuant to which it obtained an exclusive sublicense under certain patents and know-how of GSK (including such patents and know-how licensed from Merck, Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., and AstraZeneca UK Limited) to develop, manufacture and commercialize GSK’s proprietary PARP inhibitor, niraparib, in China, Hong Kong and Macau for the diagnosis and prevention of any human diseases or conditions (other than prostate cancer). We also obtained the right of first negotiation to obtain a license to develop and commercialize certain follow-on compounds of niraparib being developed by GSK in the licensed territory. Under the agreement, the Group agreed not to research, develop or commercialize certain competing products, and we also granted GSK the right of first refusal to license certain immuno-oncology assets developed by us.

In February 2018,

the Group entered into an amendment with GSK that eliminated GSK’s option to co-market niraparib in the licensed territory.

Under the terms of the agreement, the Group made an upfront payment of $15,000 and accrued two development milestone payments

totaling

$4,500 to

GSK

. On top of those, if the Group achieves other specified regulatory, development and commercialization milestones, the Group may be additionally required to pay further milestone payments up to $36,000 to

GSK

. In addition, if the Group successfully develops and commercializes the licensed products, the Group will pay

GSK

tiered royalties on the net sales of the licensed products, until the later of the expiration of the

last-to-expire

licensed patent covering the licensed product, the expiration of regulatory exclusivity for the licensed product, or the tenth anniversary of the first commercial sale of the licensed product, in each case on a

product-by-product

and

region-by-region

basis.

The Group has the right to terminate this agreement at any time by providing written notice of termination.

License and collaboration agreement with Paratek Bermuda Ltd. (“Paratek”)

In April 2017,

the Group entered into a license and collaboration agreement with Paratek Bermuda Ltd., a subsidiary of Paratek Pharmaceuticals, Inc., pursuant to which it obtained both an exclusive license under certain patents and know-how of Paratek and an exclusive sub-license under certain intellectual property that Paratek licensed from Tufts University to develop, manufacture and commercialize products containing omadacycline (ZL-2401) as an active ingredient in Greater China in the field of all human therapeutic and preventative uses other than biodefense. Under certain circumstances, the exclusive sub-license to certain intellectual property Paratek licensed from Tufts University may be converted to a non-exclusive license if Paratek’s exclusive license from Tufts University is converted to a non-exclusive license under the Tufts Agreement. The Group also obtained the right of first negotiation to be Paratek’s partner to develop certain derivatives or modifications of omadacycline in our licensed territory. Paratek retains the right to manufacture the licensed product in our licensed territory to support development and commercialization of the same outside our licensed territory. The Group also granted to Paratek a non-exclusive license to certain of our intellectual property. Under the agreement, the Group agreed not to commercialize certain competing products in our licensed territory.

Under the terms of the agreement, the Group made an upfront payment of $7,500 to Paratek and two milestone payments totaling $8,000 to Paratek and the Group may be required to pay further milestone payments of up to an aggregate of $46,500 to Paratek for the achievement of certain development and sales milestone events. In addition, the Group will pay to Paratek tiered royalties on the net sales of licensed products, until the later of the abandonment, expiration or invalidation of the

last-to-expire

licensed patent covering the licensed product, or the eleventh anniversary of the first commercial sale of the licensed product, in each case on a

product-by-product

and

region-by-region

basis.The Group has the right to terminate this agreement at any time by providing written notice of termination to Paratek.

License and collaboration agreement with Five Prime Therapeutics, Inc. (“Five Prime”)

In December 2017,

the Group entered into a license and collaboration agreement with Five Prime, pursuant to which it obtained an exclusive license under certain patents and know-how of Five Prime to develop and commercialize products containing Five Prime’s proprietary afucosylated FGFR2b antibody known as bemarituzumab (FPA144) as an active ingredient in the treatment or prevention of any disease or condition in humans in Greater China.

Under the terms of the agreement, the Group made an upfront payment of $5,000 and a milestone payment of $2,000 to Five Prime. Additionally, the Group may be required to pay further development and regulatory milestone payments of up to an aggregate of $37,000 to Five Prime. The Group is also be obligated to pay Five Prime a royalty, on a licensed

product-by-licensed

product and

region-by-region

basis, depending on the number of patients the Group enrolls in the bemarituzumab study, subject to reduction in certain circumstances, on net sales of each licensed product in the licensed territory until the latest of (i) the 11th anniversary of the first commercial sale of such licensed product in such region, (ii) the expiration of certain patents covering such licensed product in such region, and (iii) the date on which any applicable regulatory, pediatric, orphan

product

or data exclusivity with respect to such licensed product expires in such region.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Five Prime.

License and collaboration agreement with Entasis Therapeutics Holdings Inc.(“Entasis”)

In April 2018,

the Group entered into a license and collaboration agreement with Entasis, pursuant to which it obtained an exclusive license under certain patents and know-how of Entasis to develop and commercialize products containing Entasis’ proprietary compounds known as durlobactam (ETX2514) and Sulbactam (ETX2514SUL) as an active ingredient with the possibility of developing and commercializing a combination of such compounds with Imipenem in all human diagnostic, prophylactic and therapeutic uses in Greater China, Korea, Vietnam, Thailand, Cambodia, Laos, Malaysia, Indonesia, the Philippines, Singapore, Australia, New Zealand and Japan. The Group’s rights to develop and commercialize the licensed products are limited to the lead product (Sulbactam) until such lead product receives initial FDA approval in the United States.

Under the terms of the agreement, the Group made an upfront payment of $5,000 and two development milestone payments totaling $7,000 to Entasis. Additionally, the Group may be required to pay Entasis development,

regulatory and research milestone payments (other than existing ones) and commercial milestone payments of up to an aggregate of $91,600. The Group is also responsible for a portion of the costs of the global pivotal Phase III clinical trial of

SUL-DUR

outside of the territory. The Group is also obligated to pay Entasis a royalty based on a percentage of net sales of licensed products, depending on the amount of net sales of licensed products in the territory, subject to reduction in certain circumstances, until, with respect to a licensed product in a region in the territory, the latest of (i) the 10th anniversary of the first commercial sale of such licensed product in such region, (ii) the expiration of certain patents covering such licensed product in such region, and (iii) the date on which any applicable regulatory, pediatric, orphan product or data exclusivity with respect to such licensed product expires in such region.The Group has the right to terminate this agreement at any time by providing written notice of termination to Entasis.License and collaboration agreement with Crescendo Biologics Ltd. (“Crescendo”)

In May 2018, the Group and Crescendo entered into an exclusive, worldwide licensing agreement, under which the Group will develop, commercialize, and manufacture a topical, innovative antibody VH domain therapeutic for potential application in inflammatory indications.

Under the terms of the agreement, Crescendo granted to the Group a worldwide exclusive license to develop and commercialize its

product

candidate for all indications. The Group will be responsible for conducting all regulatory filings, clinical studies, and commercialization activities, with both companies participating in a Joint Development Committee.

In October 2020, the Group and Crescendo entered into a supplemental license agreement, under which Crescendo granted to the Group a

non-exclusive,

worldwide license to use the Crescendo VH HLEs in connection with the development, commercialization, manufacture and other exploitation of VH HLE licensed products.

Under the terms of these two

agreements, the Group paid two upfront fe

$4,500 and two milestone payments of $2,000

, to Crescendo, and the Group will provide development, regulatory, and commercial milestones for multiple indications up to an aggregate of

$302,075. Crescendo will also be eligible to receive tiered royalties on global sales.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Crescendo.

License and collaboration agreement with NovoCure Limited (“NovoCure”)

In September 2018,

the Group entered into a license and collaboration agreement with NovoCure, pursuant to which it obtained an exclusive license under certain patents and know-how of NovoCure to develop and commercialize Tumor Treating Fields products in all human therapeutic and preventative uses in the field of oncology in Greater China.

Under the terms of the agreement, the Group paid an upfront license fee in the amount of $15,000 and two milestone payments of $10,000 to Novocure. The Group also agreed to pay certain development, regulatory and

commercial milestone payments up to an aggregate of $68,000, and tiered royalties at percentage rates on the net sales of the Licensed Products in the Territory. The Group will purchase licensed products exclusively from Novocure at Novocure’s fully burdened manufacturing cost.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Novocure.

License and collaboration agreement with MacroGenics Inc. (“MacroGenics”)

In November 2018, The Group entered into a collaboration agreement with MacroGenics, pursuant to which it obtained an exclusive license under certain patents and know-how of MacroGenics to develop and commercialize margetuximab, tebotelimab (MGD-013) and an undisclosed multi-specific TRIDENT molecule in

pre-clinical

development, each as an active ingredient in all human fields of use, except to the extent limited by any applicable third party agreement of MacroGenics in Greater China.

Under the terms of the agreement, the Group paid an upfront license fee of $25,000 and two milestone payments in total of $4,000 to MacroGenics. The Group also agreed to pay certain development and regulatory-based milestone payments up to an aggregate of $136,000, and tiered royalties at percentage rates for net sales of Margetuximab, tebotelimab and TRIDENT molecule in the territory.

The Group has the right to terminate this agreement at any time by providing written notice of termination to MacroGenics.

License and collaboration agreement with Deciphera Pharmaceuticals, LLC (“Deciphera”)

In June 2019,

the Group entered into a license agreement with Deciphera, pursuant to which it obtained an exclusive license under certain patents and know-how of Deciphera to develop and commercialize products containing ripretinib in the field of the prevention, prophylaxis, treatment, cure or amelioration of any disease or medical condition in humans in Greater China.

Under the terms of the agreement, the Group paid Deciphera an upfront license fee of $20,000 and two milestone

payments

of $7,000. The Group also agreed to pay certain additional development, regulatory and commercial milestone payments up to an aggregate of $178,000, and tiered royalties on the net sales of the licensed products in the territory.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Deciphera.

License and collaboration agreement with Incyte Corporation (“Incyte”)

In July 2019,

the Group entered into a collaboration and license Agreement with Incyte, pursuant to which it obtained an exclusive license under certain patents and know-how of Incyte to develop, and commercialize products containing retifanlimab (INCMGA012) as an active ingredient in the treatment, palliation, diagnosis or prevention of diseases in the fields of hematology or oncology in humans in Greater China.

Under the terms of agreement, the Group paid Incyte an upfront license fee of $17,500. The Group also agreed to pay certain development, regulatory and commercial milestone payments of up to an aggregate of $60,000, and tiered royalties at percentage rates on the net sales of retifanlimab in Greater China

The Group has the right to terminate this agreement at any time by providing written notice of termination to Incyte.

Collaboration agreement with Regeneron Pharmaceuticals, Inc (“Regeneron”)

In April 2020,

the Group entered into a collaboration agreement with Regeneron Ireland Designated Activity Company, an affiliate of Regeneron pursuant to which it obtained for Greater China the oncology development and exclusive commercialization rights for products containing odronextamab as the sole active ingredient.

The Group will make payments to Regeneron based on net sales, such that Regeneron shares in a significant portion of any potential profits. Regeneron will be responsible for the manufacture and supply of odronextamab for the Group’s development and commercialization in the region.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Regeneron.

License agreement with Turning Point Therapeutics Inc (“Turning Point”)

In July 2020

the Group entered into an exclusive license agreement with Turning Point pursuant to which Turning Point exclusively licensed to the Group the rights to develop and commercialize products containing repotrectinib as an active ingredient in all human therapeutic indications, in Greater China.

Under the terms of the agreements, the Group paid an upfront payment of $25,000 to Turning Point. Turning Point is also eligible to receive up to $151,000 in development, regulatory and sales milestones. Turning Point will also be eligible to receive

mid-to-high

teen royalties based on annual net sales of repotrectinib in mainland China, Hong Kong, Macau and Taiwan.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Turning Point.

License agreement with Cullinan Pearl Corp. (“Cullinan”)

In December 2020,

the Group entered into a license agreement with Cullinan Pearl, a subsidiary of Cullinan Management, Inc., formerly Cullinan Oncology, LLC, or Cullinan, pursuant to which it obtained an exclusive license under certain patents and know-how of Cullinan to develop, manufacture and commercialize products containing CLN-081 as an active ingredient in all uses in humans and animals in Greater China.

Under the terms of the agreement, the Group accrued an upfront payment of $20,000 to Cullinan. Cullinan is also eligible to receive up to $211,000 in development, regulatory and sales-based milestone payments. Cullinan is also eligible to receive high-single-digit to

low-teen

tiered royalties based on annual net sales of

CLN-081

in Greater China.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Cullinan.

License agreement with Takeda Pharmaceutical Company Limited (“Takeda”)

In December 2020, the Group entered into an exclusive license agreement with Takeda. Under the terms of the license agreement, Takeda exclusively licensed to the Group the right to exploit products in the licensed field during the term.

Under the terms of the agreement, the Group accrued an upfront payment of $6,000 to Takeda. Takeda is also eligible to receive up to $481,500 in development, regulatory and sales-based milestone payments. Takeda is also eligible to receive high-single-digit to

low-teen

tiered royalties based on net sales of each product sold by selling party during each year of the applicable royalty term.

The Group has the right to terminate this agreement at any time by providing written notice of termination to Takeda.

As noted above, the Group has entered into various license and collaboration agreements with third party licensors to develop and commercialize product candidates. Based on the terms of these agreements the Group is contingently obligated to make additional material payments upon the achievement of certain contractually defined milestones. Based on management’s evaluation of the progress of each project noted above, the licensors will be eligible to receive from the Group up to an aggregate of approximately $2,514,147 in future milestone payments upon the achievement of contractually specified development milestones, such as regulatory approval for the product candidates, which may be before the Group has commercialized the product or received any revenue from sales of such product candidate, which may never occur.

Restricted Net Assets

12 Months Ended

Dec. 31, 2022

Restricted net assets

Restricted net assets

20.	Restricted net assets

The Group’s ability to pay dividends may depend on the Group receiving distributions of funds from its PRC subsidiary. Relevant PRC statutory laws and regulations permit payments of dividends by the Group’s PRC subsidiary only out of its retained earnings, if any, as determined in accordance with PRC accounting standards and regulations. The results of operations reflected in the consolidated financial statements prepared in accordance with U.S. GAAP differ from those reflected in the statutory financial statements of the Group’s PRC subsidiary.

In accordance with the Company law of the PRC, a domestic enterprise is required to provide statutory reserves of at least 10% of its annual

after-tax

profit until such reserve has reached 50% of its respective registered capital based on the enterprise’s PRC statutory accounts. A domestic enterprise is also required to provide discretionary surplus reserve, at the discretion of the Board of Directors, from the profits determined in accordance with the enterprise’s PRC statutory accounts. The aforementioned reserves can only be used for specific purposes and are not distributable as cash dividends. The Group’s PRC subsidiary was established as domestic invested enterprise and therefore is subject to the above

mentioned restrictions on distributable profits.

During the years ended December 31, 2018, 2019 and 2020, no appropriation to statutory reserves was made because the PRC subsidiary had substantial losses during such periods.

As a result of these PRC laws and regulations subject to the limit discussed above that require annual appropriations of

% of

after-tax

income to be set aside, prior to payment of dividends, as general reserve fund, the Group’s PRC subsidiary is restricted in their ability to transfer a portion of their net assets to the Group.

Foreign exchange and other regulation in the PRC may further restrict the Group’s PRC subsidiary from transferring funds to the Group in the form of dividends, loans and advances. As of December 31, 2019, and 2020, amounts restricted are the

paid-in

capital of the Group’s PRC subsidiaries, which amounted to $

155,858

and $

255,858

respectively.

Employee defined contribution plan

12 Months Ended

Dec. 31, 2020

Retirement Benefits [Abstract]

Employee defined contribution plan

21.	Employee defined contribution plan

Full time employees of the Group in the PRC participate in a government mandated defined contribution plan, pursuant to which certain pension benefits, medical care, employee housing fund and other welfare benefits are provided to employees. Chinese labor regulations require that the Group’s PRC subsidiary make contributions to the government for these benefits based on certain percentages of the employees’ salaries. The Group has no legal obligation for the benefits beyond the contributions made. The total amounts for such employee benefits, which were expensed as incurred, were $1,425, $5,406 and $4,373 for the years ended December 31, 2018, 2019 and 2020, respectively.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

22.	Commitments and Contingencies

(a)	Purchase commitments

As of December 31, 2020, the Group’s commitments related to purchase of property and equipment contracted but not yet reflected in the consolidated financial statement were $4,143 and $362 which are expected to be incurred in the years ended December 31, 2021 and 2022, respectively.

(b)	Contingencies

The Group is a party to or assignee of license and collaboration agreements that may require it to make future payments relating to milestone fees and royalties on future sales of licensed products (Note 19).

Subsequent Events

12 Months Ended

Dec. 31, 2020

Subsequent Events [Abstract]

Subsequent Events

23.	Subsequent events

In January 2021, the Group entered into a collaboration and license agreement with argenx BV

(“argenx”), pursuant to which the Group obtained an exclusive license under certain patents and know-how of argenx to develop and commercialize products containing efgartigimod as an active ingredient in all human and animal uses for any preventative or therapeutic indications in Greater China.

Under the terms of the agreement,

the Group will be responsible for recruiting patients in China to argenx’s global registrational trials for the development of efgartigimod. A

$75,000 upfront payment had been made to

argenx

through the issuance by the Group of 568,182 ordinary shares calculated at a price of $132.00 per share, with par value $0.00006 per share. In addition, the Group will make a guaranteed

non-creditable,

non-refundable

development cost-sharing payment of $75,000 to

argenx

, and a cash payment of $25,000 upon the first regulatory approval of a licensed product by the U.S. Food and Drug Administration for Myasthenia Gravis.

Additionally, the Group will have the right to commercialize such licensed product in the territory, during which

argenx

is eligible to receive tiered royalties based on annual net sales of all licensed product in the territory.

In January 2021

the Group entered into a license agreement with Turning Point pursuant to which the Group received an exclusive license under certain patents and know-how to develop and commercialize products containing Turning Point’s product candidate, TPX-0022, as an active ingredient in all human therapeutic indications in Greater China. The Group may, at its election and expense, subject to specified exceptions, participate in future global clinical studies of the licensed products through clinical trial sites in the licensed territory. In addition, the Group granted Turning Point a first right to negotiate a license outside the original licensed territory to a potential product candidate from one of the Group’s pipeline programs if the Group file an investigational new product application for the product candidate. The Group paid an upfront license fee in the amount of $

25,000

to Turning Point. The Group also agreed to pay certain development, regulatory and commercial milestone payments up to an aggregate of $336,000. Turning Point will also be eligible to receive

mid-teen

low-twenty-percent

basis and subject to certain reduction royalties based on annual net sales of

TPX-0022

in Greater China.

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Basis of presentation

(a) Basis of presentation

Principles of consolidation

(b) Principles of consolidation

Use of estimates

Foreign currency translation

(d) Foreign currency translation

Foreign Currency Matters

. The Group uses the United States dollar as its reporting currency.

Non-monetary

assets and liabilities are translated into the applicable functional currencies at historical exchange

Cash, cash equivalents and restricted cash

(e) Cash, cash equivalents and restricted cash

Cash and cash equivalents

Restricted cash

Restricted cash mainly consists of the bank deposits held as collateral for issuance of letters of credit.

Short-term investments

(f) Short-term investments

Accounts receivable

(g) Accounts receivable

From January 1, 2020, the Group adopted the ASU

2016-13,

Credit Losses, Measurement of Credit Losses on Financial Instruments

Inventories

(h) Inventories

non-saleable

items. The Group will record a write-down to its net realizable value in cost of sales in the period that the decline in value is first identified. Nil and $29 inventory

write-downs were

recorded as of December 31, 2019 and 2020, respectively.

Investments in equity investees

(i) Investments in equity investees

Prepayments for equipment

(j) Prepayments for equipment

The prepayments for equipment purchase are recorded in long term prepayments considering the prepayments are all related to property and equipment.

Property and equipment

(k) Property and equipment


		Useful life
Office equipment		3 years
Electronic equipment		1.25-3 years
Vehicles		4 years
Laboratory equipment		5 years
Manufacturing equipment		10 years
Leasehold improvements		lesser of useful life or lease term

Construction in progress represents property and equipment under construction and pending installation and is stated at cost less impairment losses if any.

Lease

(l) Lease

From January 1, 2019, the Group adopted the ASC Topic 842,

Leases

non-lease

At the commencement date of a lease, the Group recognizes a lease liability for future fixed lease payments and a

right-of-use

2016-02,

right-of-use

assets in the consolidated balance sheets.

Operating leases are included in operating lease

right-of-use

Lease expense is recognized on a straight-line basis over the lease term.

Land use rights

(m) Land use rights

Long term deposits

(n) Long term deposits

Long term deposits represent amounts paid in connection with the Group’s long-term lease agreements.

Value added tax recoverable

(o) Value added tax recoverable

Intangible assets

(p) Intangible assets

Impairment of long-lived assets

(q) Impairment of long-lived assets

Fair value measurements

(r) Fair value measurements

The Group applies ASC topic 820 (“ASC 820”),

Fair Value Measurements and Disclosures

, in measuring fair value. ASC 820 defines fair value, establishes a framework for measuring fair value and requires disclosures to be provided on fair value measurement.

ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2 — Include other inputs that are directly or indirectly observable in the marketplace.

Level 3 — Unobservable inputs which are supported by little or no market activity.

ASC 820 describes three main approaches

Revenue recognition

(s) Revenue recognition

In 2018, the Group adopted of ASC Topic 606 (“ASC 606”),

Revenue from Contracts with Customers,

in recognition of revenue

Under ASC 606, the Group recognizes revenue when its customer obtains control of promised goods or services, in an a

(niraparib) and Optune (Tumor Treating Fields) to customers.

The Group didn’t recognize any contract assets and contract liabilities as of December 31, 2019 and 2020.

Research and development expenses

(t) Research and development expenses

Elements of research and development expenses primarily include (i) payroll and other related costs of personnel engaged in research and development activities;

(ii) in-licensed

patent rights fees of exclusive development rights of products granted to the Group; (iii) costs related to

pre-clinical

The Group has acquired rights to develop and commercialize product candidates. Upfront payments that relate to the acquisition of a new product compound, as well as

pre-commercial

milestone payments, are immediately expensed as acquired

in-process

Deferred Income

(u) Deferred income

RMB230,000,

90,000

($13,793) was recorded in deferred income.

Comprehensive loss

(v) Comprehensive loss

Comprehensive loss is defined as the changes in equity of the Group during a period from transactions and o

her events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Among other disclosures, ASC 220,

Comprehensive Income

Stock-based compensation

(w) Share-based compensation

The Group grants share options and

non-vested

restricted shares to eligible employees, management and directors and accounts for these share-based awards in accordance with ASC 718,

Compensation-Stock Compensation.

To the extent the required vesting conditions are not met resulting in the forfeiture of the share-based awards, previously recognized compensation expense relating to those awards are reversed.

The Group determined the fair value of the stock options granted to employees using the Black-Scholes option valuation model.

Awards Granted to

Non-Employees

The Group grants share options to eligible

Non-Employees

and accounts for these share-based awards in accordance with ASC 718,

Compensation-Stock Compensation.

Non-Employees’

Non-Employees

using the Black-Scholes option valuation model.

Income taxes

(x) Income taxes

(iii) non-current

tax expense, which represents the increases and decreases in amounts related to uncertain tax positions from prior periods and not settled with cash or other tax attributes.

The Group evaluates its uncertain tax positions using the provisions of ASC 740,

Income Taxes

Earnings (Loss) per share

(y) Earnings (loss) per share

Basic earnings (loss) per ordinary share is computed by dividing net income (loss) attributable to ordinary shareholders by weighted average number of ordinary shares outstanding during the period.

Diluted earnings (loss) per ordinary share reflects the potential dilution that could occur if securities were exercised or converted into ordinary shares. The Group had stock options and

non-vested

Segment information

(z) Segment information

In accordance with ASC 280,

Segment Reportin

Concentration of risks

(aa) Concentration of risks

Concentration of customers

The following customers accounted for 10% or more of revenue for the years en

ed December 31, 2018, 2019 and 2020:


	Year ended December 31,
	2018		2019		2020
	$		$		$
A		51		5,397		*
B		34		*		*
C		14		*		*
D		*		4,682		*
E		*		*		15,774

*	Represents less than 10% of revenue for the years ended December 31, 2018, 2019 and 2020.

Concentration of suppliers

The following suppliers accounted for 10% or more of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020:

Year ended December 31,

2018

2019

2020

25,515

14,664

27,966

18,362

33,564

26,710

*	Represents less than 10% of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020.

Concentration of credit risk

Foreign currency risk

Recent accounting pronouncements

(ab) Recent accounting pronouncements

Adopted Accounting Standards

In June 2016, the FASB issued ASU

2016-13,

Credit Losses, Measurement of Credit Losses on Financial Instruments

, which has subsequently been amended by ASU

2018-19,

ASU

2019-04,

ASU

2019-05,

ASU

2019-10,

ASU

2019-11

and ASU

2020-03.

In August 2018, the FASB issued ASU

2018-13,

Fair Value Measurement (Topic 820):

Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement

In November 2018, the FASB issued ASU

2018-18,

Collaborative Arrangements (Topic 808)

Future Adoption of Accounting Standards

In December 2019, the FASB issued ASU

2019-12,

Income Taxes (Topic 740):

Simplifying the Accounting for Income Taxes

Income taxes

, and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The update is effective in fiscal years beginning after Dec

Organization and principal activities (Tables)

12 Months Ended

Dec. 31, 2020

Organization and principal activities

Schedule of Significant Operating Subsidiaries

As of December 31, 2020, the Group’s significant operating subsidiaries are as follows:


Name of company	Place of incorporation	Date of incorporation	Percentage of ownership	Principal activities

Zai Lab (Hong Kong) Limited	Hong Kong	April 29, 2013	100%	Operating company for business development and R&D activities and commercialization of innovative medicines and device
Zai Lab (Shanghai) Co., Ltd.	PRC	January 6, 2014	100%	Development and commercialization of innovative medicines and devices
Zai Lab (AUST) Pty., Ltd.	Australia	December 10, 2014	100%	Clinical trial activities
Zai Lab (Suzhou) Co., Ltd.	PRC	November 30, 2015	100%	Development and commercialization of innovative medicines
Zai Biopharmaceutical (Suzhou) Co., Ltd.	PRC	June 15, 2017	100%	Development and commercialization of innovative medicines
Zai Lab (US) LLC	U.S.	April 21, 2017	100%	Operating company for business development and R&D activities
Zai Lab International Trading (Shanghai) Co., Ltd.	PRC	November 6, 2019	100%	Commercialization of innovative medicines and devices
Zai Auto Immune (Hong Kong) Limited	Hong Kong	November 4, 2020	100%	Operating company for business development and R&D activities

Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2020

Significant Accounting Policies

Schedule of concentration of risks

Concentration of customers

The following customers accounted for 10% or more of revenue for the years en

ed December 31, 2018, 2019 and 2020:


	Year ended December 31,
	2018		2019		2020
	$		$		$
A		51		5,397		*
B		34		*		*
C		14		*		*
D		*		4,682		*
E		*		*		15,774

*	Represents less than 10% of revenue for the years ended December 31, 2018, 2019 and 2020.

Concentration of suppliers

The following suppliers accounted for 10% or more of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020:

Year ended December 31,

2018

2019

2020

25,515

14,664

27,966

18,362

33,564

26,710

*	Represents less than 10% of research and development expenses and the inventory purchases for the years ended December 31, 2018, 2019 and 2020.

Summary of Estimated Useful Lives of Property and Equipment


		Useful life
Office equipment		3 years
Electronic equipment		1.25-3 years
Vehicles		4 years
Laboratory equipment		5 years
Manufacturing equipment		10 years
Leasehold improvements		lesser of useful life or lease term

Cash and cash equivalents (Tables)

12 Months Ended

Dec. 31, 2020

Cash and Cash Equivalents [Abstract]

Summary of cash and cash equivalents


	As of December 31,
	2019		2020
	$		$
Cash at bank and in hand		75,111		441,283
Cash equivalents		821		833

		75,932		442,116

Denominated in:
US$		62,478		297,813
RMB (note (i))		6,761		23,898
Hong Kong dollar (“HK$”)		5,948		119,695
Australian dollar (“A$”)		745		710

		75,932		442,116

Note:

(i)	Certain cash and bank balances denominated in RMB were deposited with banks in the PRC. The conversion of these RMB denominated balances into foreign currencies is subject to the rules and regulations of foreign exchange control promulgated by the PRC government.

Accounts receivable (Tables)

12 Months Ended

Dec. 31, 2020

Receivables [Abstract]

Schedule of allowance for credit losses related to accounts receivable

The roll-forward of the allowance for credit losses related to accounts receivable for the year ended December 31, 2020 consists of the following activity:


	Allowance for Credit Losses
	$
Balance as of December 31, 2019		—
Current period provision for expected credit losses		1
Amounts written-off		—
Recoveries of amounts previously written-off		—

Balance as of December 31, 2020		1

Inventories (Tables)

12 Months Ended

Dec. 31, 2020

Inventories

Schedule of inventory


	As of December 31,
	2019		2020
	$		$
Finished goods		593		3,041
Raw materials		5,412		10,103

Inventories		6,005		13,144

Property and Equipment, net (Tables)

12 Months Ended

Dec. 31, 2020

Property and equipment, net

Schedule of property and equipment

Property and equipment consist of the following:


	As of December 31,
	2019			2020
	$			$
Office equipment		397			430
Electronic equipment		1,482			2,646
Vehicle		76			143
Laboratory equipment		5,854			11,933
Manufacturing equipment		11,049			12,198
Leasehold improvements		7,528			9,641
Construction in progress		428			2,423

		26,814			39,414
Less: accumulated depreciation		(5,461	)		(10,252	)

Property and equipment, net		21,353			29,162

Lease (Tables)

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Summary of supplemental information related to leases

Supplemental information related to leases was as follows:


	Year ended December 31,
	2019		2020
	$		$
Operating fixed lease cost		3,245		4,539

Summary of supplemental cash flow information related to leases

Supplemental cash flow information related to leases was as follows:


	Year ended December 31,
	2019		2020
	$		$
Cash paid for amounts included in measurement of lease liabilities		2,778		4,056
Non-cash operating lease liabilities arising from obtaining operating right-of-use assets		10,876		6,393

Summary of maturities of lease liabilities

The maturities of lease liabilities in accordance with

Leases (Topic 842)

in each of the next five years and thereafter as of December 31, 2020 were as follows:


	Year ended December 31
	$
2021		5,434
2022		4,362
2023		2,401
2024		2,238
2025		2,192
Thereafter		2,610
Total lease payments		19,237
Less: imputed interest		(639	)

Present value of minimum operating lease payments		18,598

Summary of weighted-average remaining lease terms and discount rates

Weighted-average remaining lease terms and discount rates are as follows:


	Year ended December 31,
	2019			2020
Weighted-average remaining lease term		4.4 years			5.0 years
Weighted-average discount rate		3.1	%		2.3	%

Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Revenue

Schedule of net product sales


	Year ended December 31,
	2018		2019		2020
	$		$		$
Product revenue — gross		129		12,985		57,355
Less: Rebate and sales return		—		—		(8,397	)

Product revenue — net		129		12,985		48,958

Schedule of disaggregation of net revenue


	Year ended December 31,
	2018		2019		2020
	$		$		$
ZEJULA		129		6,625		32,138
Optune		—		6,360		16,418
Others		—		—		402

Total product revenue — net		129		12,985		48,958

Income Tax (Tables)

12 Months Ended

Dec. 31, 2020

Income tax

Schedule of Loss (Income) Before Income Taxes

Loss (income) before income taxes consists of:


	Year ended December 31,
	2018		2019			2020
	$		$			$
Cayman		1,218		(3,241	)		2,612
BVI		2		2			3
PRC		127,711		185,239			220,813
HK		7,778		3,271			20,022
US		2,351		9,786			24,616
AUST		15		14			839

		139,075		195,071			268,905

Schedule of Reconciliations of PRC Statutory Income Tax Rate and Group's Effective Income Tax Rate

Reconciliations of the differences between the PRC statutory income tax rate and the Group’s effective income tax rate for the years ended December 31, 2018, 2019 and 2020 are as follows:


	Year ended December 31,
	2018			2019			2020
Statutory income tax rate		25	%		25	%		25	%
Share-based compensations		(1.93	%)		(1.51	%)		(1.36	%)
Non-deductible expenses		(0.38	%)		(0.39	%)		(1.17	%)
Prior year tax filing adjustment		1.55	%		1.93	%		1.78	%
Effect of different tax rate of subsidiary operation in other jurisdictions		(0.76	%)		0.07	%		(1.04	%)
Preferential tax rate		—			(9.14	%)		(7.48	%)
Effect of change in tax rate		—			(9.15	%)		—
Changes in valuation allowance		(23.48	%)		(6.81	%)		(15.73	%)

Effective income tax rate		—			—			—

Schedule of Components of Deferred Tax Assets and Liabilities

The principal components of the deferred tax assets and liabilities are as follows:


	Year ended December 31,
	2018			2019			2020
	$			$			$
Deferred tax assets:
Depreciation of property and equipment, net		15			57			84
Government grants		187			325			400
Deferred revenue		—			—			2,069
Public welfare donations		—			—			7,627
Net operating loss carry forwards		49,726			62,833			94,954
Less: valuation allowance		(49,928	)		(63,215	)		(105,134	)

Deferred tax assets, net		—			—			—

Schedule of Movement of Valuation Allowance

Movement of the valuation allowance is as follows:


	2019			2020
	$			$
Balance as of January 1,		(49,928	)		(63,215	)
Additions		(13,287	)		(41,919	)

Balance as of December 31,		(63,215	)		(105,134	)

Other current liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Other current liabilities

Schedule of other current liabilities

Other current liabilities consist of followings:


	As of December 31,
	2019		2020
	$		$
Payroll		9,590		13,694
Professional service fee		774		3,128
Payables for purchase of property and equipment		416		788
Payables for purchase of intangible assets		—		70
Accrued rebate to distributors		—		7,067
Others (note (i))		2,394		5,449

Total		13,174		30,196

Note:

(i)	Others are mainly payments from employees for exercising the share-based compensations, tax payables, and payables related to travel and business entertainment expenses and conference fee.

Loss per share (Tables)

12 Months Ended

Dec. 31, 2020

Loss per share

Summary of basic and diluted net loss per share

Basic and diluted net loss per share for each of the years presented are calculated as follow:


	For the years ended December 31,
	2018			2019			2020
Numerator:
Net loss attributable to ordinary shareholders		(139,075	)		(195,071	)		(268,905	)
Denominator:
Weighted average number of ordinary shares- basic and diluted		52,609,810			64,369,490			77,667,743

Net loss per share-basic and diluted		(2.64	)		(3.03	)		(3.46	)

Summary of anti-dilutive excluded from the calculation of diluted loss per share

As a result of the Group’s net loss for the three years ended December 31, 2018, 2019 and 2020, share options and

non-vested

restricted shares outstanding in the respective periods were excluded from the calculation of diluted loss per share as their inclusion would have been anti-dilutive.


	As of December 31,
	2018		2019		2020
Share options		8,761,735		9,122,980		8,755,920
Non-vested restricted shares		1,112,001		743,268		541,750

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2020

Related party transactions

Schedule of Major Related Party and Relationship

The table below sets forth the major related party and the relationship with the Group as of December 31, 2020:


Company Name		Relationship with the Group
MEDx (Suzhou) Translational Medicine Co., Ltd. (Formerly known as Qiagen (Suzhou) translational medicine Co., Ltd)		Significant influence held by Samantha (Ying) Du’s (Director, Chairwoman and Chief Executive Officer of the Company) immediate family

Share-based compensation (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of assumptions used to estimate the fair values of share options granted

The following table presents the assumptions used to estimate the fair values of the share options granted in the years presented:


	2018	2019	2020

Risk-free rate of return	2.7%-3.2 %	1.6%-2.5 %	0.4%-0.8 %
Contractual life of option	10 years	10 years	10 years
Expected term	6.5 years	6 or 6.5 years	6 or 6.5 years
Estimated volatility rate	70%	70%	70%
Expected dividend yield	0%	0%	0%
Fair value of underlying ordinary shares	$17.60-$24.58	$27.23-$41.59	$44.94-$128.72

Summary of option activity

A summary of option activity under the 2015 Plan and 2017 Plan during the years ended December 31, 2018, 2019 and 2020 is presented below:


	Number of options			Weighted average exercise price		Weighted average remaining contractual term		Aggregate intrinsic value
				$		Years		$
Outstanding at January 1, 2018		6,548,377			1.28		8.06		130,669
Granted		2,759,750			21.15		—		—
Exercised		(256,065	)		0.76		—		—
Forfeited		(290,327	)		3.73		—		—
Outstanding at December 31, 2018		8,761,735			7.47		7.80		138,010
Granted		1,067,385			32.22		—		—
Exercised		(670,939	)		1.57		—		—
Forfeited		(35,201	)		25.99		—		—
Outstanding at December 31, 2019		9,122,980			10.73		7.16		281,562
Granted		1,220,177			63.98		—		—
Exercised		(899,361	)		7.41		—		—
Forfeited		(687,876	)		26.37		—		—
Outstanding at December 31, 2020		8,755,920			17.26		6.53		1,033,899

Vested and exercisable as of December 31, 2020		5,073,001			4.90		5.47		661,708
Vested or expected to vest as of December 31, 2020		8,755,920			17.26		6.53		1,033,899

Summary of non-vested restricted share activity

The following table summarized the Group’s

non-vested

restricted share activity in 2020:


	Numbers of non-vested restricted shares			Weighted average grant date fair value
				$
Non-vested as of January 1, 2019		1,112,001			15.13
Granted		171,000			27.55
Vested		(539,733	)		8.97
Non-vested as of December 31, 2019		743,268			22.45
Granted		159,250			74.55
Vested		(225,768	)		22.98
Forfeited		(135,000	)		23.20

Non-vested as of December 31, 2020		541,750			37.36

Options [Member]

Allocation of compensation expense related to restricted shares


	Year ended December 31,
	2018		2019		2020
	$		$		$
Selling, general and administrative		4,428		6,931		11,492
Research and development		4,975		7,994		7,203
Total		9,403		14,925		18,695

Restricted Shares [Member]

Allocation of compensation expense related to restricted shares

As of December 31, 2020, there was $16,335 of total unrecognized compensation expense related to

non-vested


	Year ended December 31,
	2018		2019		2020
	$		$		$
Selling, general and administrative		2,206		3,643		4,226
Research and development		620		1,723		1,909

Total		2,826		5,366		6,135

Accumulated Other Comprehensive (Loss) Income (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Summary of Accumulated Other Comprehensive (Loss) Income

The movement of accumulated other comprehensive income (loss) is as follows:


	Foreign currency translation adjustments
	$
Balance as of January 1, 2018		450
Other comprehensive income		2,212
Balance as of December 31, 2018		2,662
Other comprehensive income		1,958
Balance as of December 31, 2019		4,620
Other comprehensive loss		(19,144	)

Balance as of December 31, 2020		(14,524	)

Organization and principal activities - Schedule of Significant Operating Subsidiaries (Details)	12 Months Ended
	Dec. 31, 2020
Zai Lab (Hong Kong) Limited
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	Hong Kong
Date of incorporation	Apr. 29, 2013
Percentage of ownership	100.00%
Principal activities	Operating company for business development and R&D activities and commercialization of innovative medicines and device
Zai Lab (Shanghai) Co., Ltd
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	PRC
Date of incorporation	Jan. 06, 2014
Percentage of ownership	100.00%
Principal activities	Development and commercialization of innovative medicines and devices
Zai Lab (AUST) Pty., Ltd
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	Australia
Date of incorporation	Dec. 10, 2014
Percentage of ownership	100.00%
Principal activities	Clinical trial activities
Zai Lab (Suzhou) Co., Ltd
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	PRC
Date of incorporation	Nov. 30, 2015
Percentage of ownership	100.00%
Principal activities	Development and commercialization of innovative medicines
Zai Biopharmaceutical (Suzhou) Co., Ltd
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	PRC
Date of incorporation	Jun. 15, 2017
Percentage of ownership	100.00%
Principal activities	Development and commercialization of innovative medicines
Zai Lab (US) LLC
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	U.S.
Date of incorporation	Apr. 21, 2017
Percentage of ownership	100.00%
Principal activities	Operating company for business development and R&D activities
Zai Lab International Trading (Shanghai) Co., Ltd
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	PRC
Date of incorporation	Nov. 06, 2019
Percentage of ownership	100.00%
Principal activities	Commercialization of innovative medicines and devices
Zai Auto Immune Hong Kong Limited
Subsidiary Of Limited Liability Company Or Limited Partnership [Line Items]
Place of incorporation	Hong Kong
Date of incorporation	Nov. 04, 2020
Percentage of ownership	100.00%
Principal activities	Operating company for business development and R&D activities

Summary of significant accounting policies - Additional Information (Details) ¥ in Thousands, $ in Thousands	1 Months Ended		12 Months Ended
	May 31, 2020 CNY (¥)	Apr. 30, 2020 CNY (¥)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 CNY (¥)	Dec. 31, 2019 CNY (¥)
Significant Accounting Policies
Inventory write-down			$ 29	$ 0	$ 0
Impairment of investments			0	$ 0	0
Land use rights lease term				30 years
Amortization expenses			307	$ 305	15
Finite-lived intangible assets, Amortization expense, 2021			402
Finite-lived intangible assets, Amortization expense, 2022			399
Finite-lived intangible assets, Amortization expense, 2023			386
Finite-lived intangible assets, Amortization expense, 2024			270
Finite-lived intangible assets, Amortization expense, after year five			55
Impairment of long-lived assets			$ 0	0	0
Revenue, Practical Expedient, Financing Component [true false]			true
Cash grants recorded in other income			$ 7,289	2,151	1,332
Cash grants recorded in deferred income			$ 2,519	2,023
Reimbursement recognized period			5 years
Unrecognized tax benefits and related interest and penalties			$ 0	0	0
Number of reportable segments \| segment			1
Aggregate amount of cash and cash equivalents			$ 442,116	$ 75,932	62,952
Foreign Currency Risk \| Cash and Cash Equivalents
Significant Accounting Policies
Concentration risk percentage			5.00%	9.00%
Aggregate amount of cash and cash equivalents \| ¥						¥ 155,934	¥ 47,168
Deferred Income
Significant Accounting Policies
Reimbursements recognized			$ 546	$ 858
Other Income
Significant Accounting Policies
Reimbursements recognized			$ 312	$ 312	$ 312
Minimum
Significant Accounting Policies
Intangible assets amortization period			1 year
Maximum
Significant Accounting Policies
Intangible assets amortization period			5 years
Exclusive Promotion Agreement \| Hanhui [Member]
Significant Accounting Policies
Payment of upfront fees \| ¥	¥ 230,000	¥ 90,000
Upfront payment recorded in deferred income			$ 13,793			¥ 90,000

Summary of significant accounting policies - Summary of Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Office Equipment
Property Plant And Equipment
Estimated useful lives of property and equipment	3 years
Electronic Equipment \| Minimum
Property Plant And Equipment
Estimated useful lives of property and equipment	1 year 3 months
Electronic Equipment \| Maximum
Property Plant And Equipment
Estimated useful lives of property and equipment	3 years
Vehicles
Property Plant And Equipment
Estimated useful lives of property and equipment	4 years
Laboratory Equipment
Property Plant And Equipment
Estimated useful lives of property and equipment	5 years
Manufacturing Equipment
Property Plant And Equipment
Estimated useful lives of property and equipment	10 years
Leasehold Improvements
Property Plant And Equipment
Estimated useful lives of property and equipment	lesser of useful life or lease term

Summary of significant accounting policies - Concentration of customers and concentration of suppliers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Significant Accounting Policies
Revenue	$ 48,958	$ 12,985	$ 129
Research and development expenses	222,711	142,221	120,278
Revenue \| Concentration of customers \| A
Significant Accounting Policies
Revenue		5,397	51
Revenue \| Concentration of customers \| B
Significant Accounting Policies
Revenue			34
Revenue \| Concentration of customers \| C
Significant Accounting Policies
Revenue			14
Revenue \| Concentration of customers \| D
Significant Accounting Policies
Revenue		4,682
Revenue \| Concentration of customers \| E
Significant Accounting Policies
Revenue	15,774
Research and Development Expenses \| Concentration of suppliers \| A
Significant Accounting Policies
Research and development expenses			25,515
Research and Development Expenses \| Concentration of suppliers \| B
Significant Accounting Policies
Research and development expenses			$ 14,664
Research and Development Expenses \| Concentration of suppliers \| C
Significant Accounting Policies
Research and development expenses		27,966
Research and Development Expenses \| Concentration of suppliers \| D
Significant Accounting Policies
Research and development expenses		$ 18,362
Research and Development Expenses \| Concentration of suppliers \| E
Significant Accounting Policies
Research and development expenses	33,564
Research and Development Expenses \| Concentration of suppliers \| F
Significant Accounting Policies
Research and development expenses	$ 26,710

Summary of significant accounting policies - Concentration of customers and concentration of suppliers (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue \| Concentration of customers
Significant Accounting Policies
Concentration risk percentage	10.00%	10.00%	10.00%
Research and Development Expenses \| Concentration of suppliers
Significant Accounting Policies
Concentration risk percentage	10.00%	10.00%	10.00%

Cash and cash equivalents - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash And Cash Equivalents [Line Items]
Cash at bank and in hand	$ 441,283	$ 75,111
Cash equivalents	833	821
Cash and cash equivalents	442,116	75,932	$ 62,952
Denominated in US$
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	297,813	62,478
Denominated in RMB
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	23,898	6,761
Denominated in Hong Kong dollar
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	119,695	5,948
Denominated in Australia dollar
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 710	$ 745

Restricted cash, non-current - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Restricted Cash [Abstract]
Restricted cash, non-current	$ 743	$ 510

Short-term investments (Details) - USD ($) $ in Thousands	12 Months Ended
Short-term investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Maturities of Time Deposits, Description	time deposits with original maturities between three months and one year
Time deposits, Interest income	$ 4,860	$ 7,778	$ 2,359
Minimum
Schedule Of Available For Sale Securities [Line Items]
Time deposits, Maturity period	3 months
Maximum
Schedule Of Available For Sale Securities [Line Items]
Time deposits, Maturity period	1 year

Accounts receivable (Details) $ in Thousands	12 Months Ended
Accounts receivable (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 31, 2019	$ 0
Current period provision for expected credit losses	1
Balance as of December 31, 2020	$ 1

Inventories - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Inventory write-down	$ 29	$ 0	$ 0
Inventory balance	$ 13,144	$ 6,005

Inventories - Schedule of inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventories
Finished goods	$ 3,041	$ 593
Raw materials	10,103	5,412
Inventories	$ 13,144	$ 6,005

Investments in Equity Investees - Additional Information (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2017 CNY (¥) item
Equity And Cost Method Investments
Share of loss from equity method investment	$ (1,119)	$ (752)	$ (587)
JING
Equity And Cost Method Investments
Share of loss from equity method investment	$ 1,119	$ 752	$ 587
Number of third-parties \| item				3
Capital contribution commitment \| ¥				¥ 26,250
Percentage of equity interest			20.00%	20.00%

Property and Equipment, net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment
Property and equipment, gross	$ 39,414	$ 26,814
Less: accumulated depreciation	(10,252)	(5,461)
Property and equipment, net	29,162	21,353
Office Equipment
Property Plant And Equipment
Property and equipment, gross	430	397
Electronic Equipment
Property Plant And Equipment
Property and equipment, gross	2,646	1,482
Vehicle
Property Plant And Equipment
Property and equipment, gross	143	76
Laboratory Equipment
Property Plant And Equipment
Property and equipment, gross	11,933	5,854
Manufacturing Equipment
Property Plant And Equipment
Property and equipment, gross	12,198	11,049
Leasehold Improvements
Property Plant And Equipment
Property and equipment, gross	9,641	7,528
Construction in Progress
Property Plant And Equipment
Property and equipment, gross	$ 2,423	$ 428

Property and Equipment, net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property and equipment, net
Depreciation expenses	$ 1,634	$ 3,372	$ 4,324

Lease - Additional Information (Details)	Dec. 31, 2020
Minimum
Lease
Operating lease remaining lease term	1 year
Maximum
Lease
Operating lease remaining lease term	7 years

Lease - Summary of Supplemental Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating fixed lease cost	$ 4,539	$ 3,245

Lease - Summary of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Cash paid for amounts included in measurement of lease liabilities	$ 4,056	$ 2,778
Non-cash operating lease liabilities arising from obtaining operating right-of-use assets	$ 6,393	$ 10,876

Lease - Summary of Maturities of Lease Liabilities (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Maturities of lease liabilities
2021	$ 5,434
2022	4,362
2023	2,401
2024	2,238
2025	2,192
Thereafter	2,610
Total lease payments	19,237
Less: imputed interest	(639)
Present value of minimum operating lease payments	$ 18,598

Lease - Summary of Weighted-Average Remaining Lease Terms and Discount Rates (Details)	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Weighted-average remaining lease term	5 years	4 years 4 months 24 days
Weighted-average discount rate	2.30%	3.10%

Revenue - (Details) - USD ($) $ in Thousands	12 Months Ended
Revenue - (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue
Product revenue - gross	$ 57,355	$ 12,985	$ 129
Less: Rebate and sales return	(8,397)
Product revenue - net	$ 48,958	$ 12,985	$ 129

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Revenue - Disaggregation of net revenue by product (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue
Total product revenue - net	$ 48,958	$ 12,985	$ 129
ZEJULA
Disaggregation of Revenue
Total product revenue - net	32,138	6,625	$ 129
Optune
Disaggregation of Revenue
Total product revenue - net	16,418	$ 6,360
Other
Disaggregation of Revenue
Total product revenue - net	$ 402

- Definition

+ References

+ Details

Income Tax - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Taxable income	$ (268,905)	$ (195,071)	$ (139,075)
Provision for income taxes
Amounts of operating loss carry forwards	$ 605,226	$ 403,460	$ 204,693
Earliest Tax Year
Income Tax Disclosure [Line Items]
Operating loss carry forwards expiration	Dec. 31, 2021
Latest Tax Year
Income Tax Disclosure [Line Items]
Operating loss carry forwards expiration	Dec. 31, 2030
PRC
Income Tax Disclosure [Line Items]
Statutory income tax rate	25.00%	25.00%	25.00%
Taxable income	$ (220,813)	$ (185,239)	$ (127,711)
Preferential tax rate	15.00%		15.00%
Zai Lab (AUST) Pty., Ltd
Income Tax Disclosure [Line Items]
Statutory income tax rate	30.00%
Taxable income	$ 0	0	$ 0
Provision for income taxes	$ 0	0	0
Zai Lab (US) LLC
Income Tax Disclosure [Line Items]
Statutory income tax rate	21.00%
Taxable income	$ 0	0	0
Provision for income taxes	0	0	0
Zai Lab (Hong Kong) Limited
Income Tax Disclosure [Line Items]
Provision for income taxes	0	0	0
Withholding taxes on remittance of dividends	$ 0	$ 0	$ 0
Zai Lab (Hong Kong) Limited \| First two million
Income Tax Disclosure [Line Items]
Statutory income tax rate	8.25%
Zai Lab (Hong Kong) Limited \| Above two million
Income Tax Disclosure [Line Items]
Statutory income tax rate	16.50%
Zai Lab International Trading (Shanghai) Co., Ltd
Income Tax Disclosure [Line Items]
Statutory income tax rate	25.00%
Zai Lab (Suzhou) Co., Ltd
Income Tax Disclosure [Line Items]
Statutory income tax rate	25.00%
Zai Lab (Shanghai) Co., Ltd
Income Tax Disclosure [Line Items]
Preferential tax rate	15.00%
Zai Biopharmaceutical (Suzhou) Co., Ltd
Income Tax Disclosure [Line Items]
Statutory income tax rate	25.00%

Income Tax - Schedule of Loss (income) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	$ 268,905	$ 195,071	$ 139,075
Cayman
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	2,612	(3,241)	1,218
BVI
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	3	2	2
PRC
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	220,813	185,239	127,711
HK
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	20,022	3,271	7,778
US
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	24,616	9,786	2,351
AUST
Income Tax Disclosure [Line Items]
Loss (income) before income taxes	$ 839	$ 14	$ 15

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Income Tax - Schedule of Reconciliations of PRC Statutory Income Tax Rate and Group's Effective Income Tax Rate (Details) - PRC	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Statutory income tax rate	25.00%	25.00%	25.00%
Share-based compensations	(1.36%)	(1.51%)	(1.93%)
Non-deductible expenses	(1.17%)	(0.39%)	(0.38%)
Prior year tax filing adjustment	1.78%	1.93%	1.55%
Effect of different tax rate of subsidiary operation in other jurisdictions	(1.04%)	0.07%	(0.76%)
Preferential tax rate	(7.48%)	(9.14%)
Effect of change in tax rate		(9.15%)
Changes in valuation allowance	(15.73%)	(6.81%)	(23.48%)
Effective income tax rate	0.00%	0.00%	0.00%

Income Tax - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Depreciation of property and equipment, net	$ 84	$ 57	$ 15
Government grants	400	325	187
Deferred revenue	2,069
Public welfare donations	7,627
Net operating loss carry forwards	94,954	62,833	49,726
Less: valuation allowance	(105,134)	(63,215)	(49,928)
Deferred tax assets, net	$ 0	$ 0	$ 0

Income Tax - Schedule of Movement of Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income tax
Beginning Balance	$ (63,215)	$ (49,928)
Additions	(41,919)	(13,287)
Ending Balance	$ (105,134)	$ (63,215)

Short-term borrowings - Additional Information (Details) - CNY (¥) ¥ in Thousands			12 Months Ended
	Dec. 12, 2018	Jun. 25, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Zai Lab (Suzhou) Co., Ltd
Line Of Credit Facility [Line Items]
Facility agreement expiration period		3 years
Facility agreement amount		¥ 25,000
Facility agreement, Outstanding amount			¥ 0
Short-term borrowing, average interest rate		4.785%
Facility agreement, loan drawn down amount				¥ 30,000	¥ 20,000
Facility agreement, Repayment of outstanding amount			25,000	25,000
Zai Biopharmaceutical (Suzhou) Co., Ltd
Line Of Credit Facility [Line Items]
Facility agreement expiration period	3 years
Facility agreement amount	¥ 40,000
Facility agreement, Outstanding amount			0
Short-term borrowing, average interest rate	4.785%
Facility agreement, loan drawn down amount				20,000	¥ 5,000
Facility agreement, Repayment of outstanding amount			¥ 20,000	¥ 5,000

Other current liabilities - Schedule of Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other current liabilities
Payroll	$ 13,694	$ 9,590
Professional service fee	3,128	774
Payables for purchase of property and equipment	788	416
Payables for purchase of intangible assets	70
Accrued rebate to distributors	7,067
Others	5,449	2,394
Total	$ 30,196	$ 13,174

Loss per share - Summary of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss attributable to ordinary shareholders	$ (268,905)	$ (195,071)	$ (139,075)
Denominator:
Weighted average number of ordinary shares- basic and diluted	77,667,743	64,369,490	52,609,810
Net loss per share-basic and diluted	$ (3.46)	$ (3.03)	$ (2.64)

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details

Loss per share - Summary of Anti-Dilutive Shares Excluded from Calculation of Diluted Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted loss per share	8,755,920	9,122,980	8,761,735
Non-Vested Restricted Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive shares excluded from calculation of diluted loss per share	541,750	743,268	1,112,001

Related party transactions - Schedule of Major Related Party and Relationship (Details)	12 Months Ended
	Dec. 31, 2020
MEDx (Suzhou) Translational Medicine Co., Ltd. (Formerly known as Qiagen (Suzhou) translational medicine Co., Ltd)
Related Party Transaction [Line Items]
Relationship with the Group	Significant influence held by Samantha (Ying) Du’s (Director, Chairwoman and Chief Executive Officer of the Company) immediate family

- Definition

A description of the related party transaction, including transactions to which no amounts or nominal amounts were ascribed and such other information deemed necessary to an understanding of the effects of the transactions on the financial statements. Examples of common related party transactions are, sales, purchases and transfers of realty and personal property, services received or furnished, loans and leases to and from top management and affiliates.

+ References + Details

Related party transactions - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Research and development \| MEDx (Suzhou) Translational Medicine Co., Ltd. (Formerly known as Qiagen (Suzhou) translational medicine Co., Ltd)
Related Party Transaction [Line Items]
Transactions between its related party	$ 678	$ 234	$ 126

Share-based compensation - Share Options - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 05, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares authorized	7,369,767			4,140,945
Options granted	1,220,177	1,067,385	2,759,750
Exercise price of options	$ 63.98	$ 32.22	$ 21.15
Weighted-average grant-date fair value of options granted	$ 40.60	$ 20.98	$ 14.03
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense	$ 18,695	$ 14,925	$ 9,403
Unrecognized compensation expense related to unvested share options granted	$ 71,909
Recognized over a weighted-average period	1 year 6 months 29 days
Management, Employees and Individual Advisors \| Two Thousand Seventeen Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted	1,220,177	1,067,385	2,759,750
Options granted contractual term	10 years	10 years	10 years
Vesting period			5 years
Management, Employees and Individual Advisors \| Minimum \| Two Thousand Seventeen Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price of options	$ 44.94	$ 27.23	$ 17.60
Vesting period		3 years
Management, Employees and Individual Advisors \| Minimum \| Vesting anniversary year after the grant date \| Two Thousand Seventeen Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option vesting percentage	20.00%	20.00%
Management, Employees and Individual Advisors \| Maximum \| Two Thousand Seventeen Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price of options	$ 128.72	$ 41.59	$ 24.58
Vesting period	3 years	5 years
Management, Employees and Individual Advisors \| Maximum \| Vesting anniversary year after the grant date \| Two Thousand Seventeen Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option vesting percentage	33.30%	33.30%	20.00%

Share-based compensation - Schedule of Assumptions Used to Estimate Fair Values of Share Options Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free rate of return	0.40%	1.60%	2.70%
Risk-free rate of return	0.80%	2.50%	3.20%
Contractual life of option	10 years	10 years	10 years
Estimated volatility rate	70.00%	70.00%	70.00%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	6 years	6 years
Fair value of underlying ordinary shares	$ 44.94	$ 27.23	$ 17.60
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	6 years 6 months	6 years 6 months	6 years 6 months
Fair value of underlying ordinary shares	$ 128.72	$ 41.59	$ 24.58

Share-based compensation - Summary of Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Share-based compensation
Number of options, Outstanding, Beginning Balance	9,122,980	8,761,735	6,548,377
Number of options, Granted	1,220,177	1,067,385	2,759,750
Number of options, Exercised	(899,361)	(670,939)	(256,065)
Number of options, Forfeited	(687,876)	(35,201)	(290,327)
Number of options, Outstanding, Ending Balance	8,755,920	9,122,980	8,761,735	6,548,377
Number of options, Vested and Exercisable as of December 31, 2020	5,073,001
Number of options, Vested or expected to vest as of December 31, 2020	8,755,920
Weighted average exercise price, Outstanding, Beginning Balance	$ 10.73	$ 7.47	$ 1.28
Weighted average exercise price, Granted	63.98	32.22	21.15
Weighted average exercise price, Exercised	7.41	1.57	0.76
Weighted average exercise price, Forfeited	26.37	25.99	3.73
Weighted average exercise price, Outstanding, Ending Balance	17.26	$ 10.73	$ 7.47	$ 1.28
Weighted average exercise price, Vested and Exercisable as of December 31, 2020	4.90
Weighted average exercise price, Vested or expected to vest as of December 31, 2020	$ 17.26
Weighted average remaining contractual term, Outstanding	6 years 6 months 10 days	7 years 1 month 28 days	7 years 9 months 18 days	8 years 21 days
Weighted average remaining contractual term, Vested and Exercisable as of December 31, 2020	5 years 5 months 19 days
Weighted average remaining contractual term, Vested or expected to vest as of December 31, 2020	6 years 6 months 10 days
Aggregate intrinsic value, Outstanding	$ 1,033,899	$ 281,562	$ 138,010		$ 130,669
Aggregate intrinsic value, Vested and Exercisable as of December 31, 2020	661,708
Aggregate intrinsic value, Vested or expected to vest as of December 31, 2020	$ 1,033,899

Share-based compensation - Allocation of Compensation Expense Related to Option (Details) - Stock Options - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	$ 18,695	$ 14,925	$ 9,403
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	11,492	6,931	4,428
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	$ 7,203	$ 7,994	$ 4,975

Share-based compensation - Non-vested Restricted Shares - Additional Information (Details) - Non-Vested Restricted Shares - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation	$ 16,335
Compensation expense	$ 6,135	$ 5,366	$ 2,826
Independent Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted	50,000	50,000	62,500
Management
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted	109,250	121,000	694,500
Management \| Each yearly anniversary from the date of the agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option vesting percentage	20.00%	20.00%	20.00%

Share-based compensation - Summary of Non-vested Restricted Share Activity (Details) - Non-Vested Restricted Shares - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Numbers of non-vested restricted shares, Beginning Balance	743,268	1,112,001
Numbers of non-vested restricted shares, Granted	159,250	171,000
Numbers of non-vested restricted shares, Vested	(225,768)	(539,733)
Numbers of non-vested restricted shares, Forfeited	135,000
Numbers of non-vested restricted shares, Ending Balance	541,750	743,268
Weighted average grant date fair value, Beginning Balance	$ 22.45	$ 15.13
Weighted average grant date fair value, Granted	74.55	27.55
Weighted average grant date fair value, Vested	22.98	8.97
Weighted average grant date fair value, Forfeited	23.20
Weighted average grant date fair value, Ending Balance	$ 37.36	$ 22.45

Share-based compensation - Allocation of Compensation Expense Related to Restricted Shares (Details) - Non-Vested Restricted Shares - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	$ 6,135	$ 5,366	$ 2,826
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	4,226	3,643	2,206
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expense	$ 1,909	$ 1,723	$ 620

Accumulated Other Comprehensive (Loss) Income - Summary of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 294,660	$ 251,081	$ 235,171
Balance	1,169,345	294,660	251,081
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	4,620	2,662	450
Other comprehensive income	(19,144)	1,958	2,212
Balance	$ (14,524)	$ 4,620	$ 2,662

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References + Details

Licenses and collaborative arrangement (Details) $ in Thousands	1 Months Ended											12 Months Ended
	Dec. 31, 2020	Apr. 30, 2020	Jul. 31, 2019 USD ($)	Jun. 30, 2019 USD ($) Milestone	Nov. 30, 2018 USD ($) Milestone	Sep. 30, 2018 USD ($) Milestone	May 31, 2018 USD ($) Milestone	Apr. 30, 2018 USD ($) Milestone	Dec. 31, 2017 USD ($) Milestone	Apr. 30, 2017 USD ($) Milestone	Sep. 30, 2016 USD ($) Milestone	Dec. 31, 2020 USD ($)
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future milestone payments to be made upon achievement												$ 2,514,147
Tesaro
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date											2016-09
Payment of upfront fees											$ 15,000
Number of milestone payments \| Milestone											2
Milestone payments											$ 4,500
Tesaro \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments											$ 36,000
Paratek
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date										2017-04
Payment of upfront fees										$ 7,500
Number of milestone payments \| Milestone										2
Milestone payments										$ 8,000
Paratek \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments										$ 46,500
Five Prime
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date									2017-12
Payment of upfront fees									$ 5,000
Number of milestone payments \| Milestone									1
Milestone payments									$ 2,000
Five Prime \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments									$ 37,000
Entasis
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date								2018-04
Payment of upfront fees								$ 5,000
Number of milestone payments \| Milestone								2
Milestone payments								$ 7,000
Entasis \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments								$ 91,600
Deciphera Pharmaceuticals LLC
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date				2019-06
Payment of upfront fees				$ 20,000
Number of milestone payments \| Milestone				2
Milestone payments				$ 7,000
Deciphera Pharmaceuticals LLC \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments				$ 178,000
Crescendo
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date							2018-05
Payment of upfront fees							$ 4,500
Number of up front payments							2
Number of milestone payments \| Milestone							2
Milestone payments							$ 2,000
Crescendo \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments							$ 302,075
Novocure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date						2018-09
Payment of upfront fees						$ 15,000
Number of milestone payments \| Milestone						2
Milestone payments						$ 10,000
Novocure \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments						$ 68,000
MacroGenics
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date					2018-11
Payment of upfront fees					$ 25,000
Number of milestone payments \| Milestone					2
Milestone payments					$ 4,000
MacroGenics \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments					$ 136,000
Incyte Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date			2019-07
Payment of upfront fees			$ 17,500
Incyte Corporation \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payments			$ 60,000
Regeneron
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date		2020-04
Turning Point Therapeutics Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date												2020-07
Payment of upfront fees												$ 25,000
Turning Point Therapeutics Inc \| Potential Development Regulatory and Sales Based Milestone
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future milestone payments to be made upon achievement												151,000
Cullinan Pearl Corp
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date	2020-12
Payment of upfront fees												20,000
Cullinan Pearl Corp \| Potential Development Regulatory and Sales Based Milestone
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future milestone payments to be made upon achievement												211,000
Takeda Pharmaceutical Company Limited
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement date	2020-12
Payment of upfront fees												6,000
Takeda Pharmaceutical Company Limited \| Potential Development Regulatory and Sales Based Milestone
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future milestone payments to be made upon achievement												$ 481,500

Restricted Net Assets (Details) - PRC - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted net assets
Minimum required percentage of statutory reserves	10.00%
Percentage of statutory reserves to respective registered capital	50.00%
Statutory reserves	$ 0	$ 0	$ 0
Restricted amount by subsidiaries	$ 255,858	$ 155,858

Employee defined contribution plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee benefits, expense	$ 4,373	$ 5,406	$ 1,425

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property and Equipment
Loss Contingencies [Line Items]
Purchase obligation	$ 362	$ 4,143

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Par value per share		$ 0.00006	$ 0.00006
Subsequent Event \| Turning Point Therapeutics Inc
Subsequent Event [Line Items]
Payment of upfront fees	$ 25,000
Future milestone payments to be made upon achievement	$ 336,000
License agreement date	2021-01
Subsequent Event \| Argenx BV
Subsequent Event [Line Items]
Payment of upfront fees	$ 75,000
No of shares Issued	568,182
Sale of stock price per share	$ 132.00
Par value per share	$ 0.00006
Future milestone payments to be made upon achievement	$ 25,000
License agreement date	2021-01
Subsequent Event \| Argenx BV \| Potential Development Regulatory and Sales Based Milestone
Subsequent Event [Line Items]
Future milestone payments to be made upon achievement	$ 75,000