Press Release

SAN DIEGO, Jan. 21, 2022 /PRNewswire/ -- Mirati Therapeutics, Inc. (NASDAQ: MRTX), a clinical-stage targeted oncology company, today announced positive results from a Phase 2 cohort of the KRYSTAL-1 study evaluating adagrasib at the 600mg BID dose in patients with pretreated pancreatic ductal adenocarcinoma and other gastrointestinal (GI) tumors harboring a KRAS^G12C mutation, including cancers of the biliary tract, appendix, small bowel, gastro-esophageal junction, and esophagus. Results showed that adagrasib demonstrated significant clinical activity and broad disease control. The findings (Abstract # 519) will be presented today at 10:00 a.m. ET during a rapid abstract session at the 2022 American Society for Clinical Oncology (ASCO) Gastrointestinal (GI) Cancers Symposium.

Dr. Tanios S. Bekaii-Saab, an investigator of the KRYSTAL-1 study, commented, "Gastrointestinal cancers are some of the most common cancers and continue to be associated with poor survival outcomes despite recent advances, especially in patients with GI tumors harboring a KRAS^G12C mutation. New clinical data presented at ASCO GI show that adagrasib, an inhibitor of KRAS^G12C, demonstrated promising clinical activity in patients with pancreatic cancer and other GI tumors. These findings build on the previously reported positive adagrasib clinical data in colorectal and pancreatic cancers, and are highly encouraging, warranting further investigation of adagrasib in this setting."

Summary of Clinical Results

• As of September 10, 2021, the subset of patients with GI cancers harboring a KRAS^G12C mutation enrolled in the adagrasib monotherapy arm (n=30) received at least two prior lines of systemic anticancer therapies, and had a median follow up of 6.3 months.
   
• Of the evaluable patients (n=27), the objective response rate (ORR) was 41% and the disease control rate (DCR) was 100%. In evaluable patients with pancreatic cancer (n=10), the response rate (RR) was 50%, including 1 unconfirmed partial response (PR); the median duration of response (mDOR) was 7.0 months, with a median follow up of 8.1 months. In patients with other GI tumors (n=17), the RR was 35%, with two unconfirmed PRs; the mDOR was 7.9 months in these patients, with a median follow up of 6.3 months.
   
• The median progression free survival (mPFS) in patients with pancreatic cancer was 6.6 months (95% Confidence Interval, CI: 1.0, 9.7), and in patients with the other GI tumors, the mPFS was 7.9 months (95% CI 6.90–11.30).
   
• In the overall subset of patients with KRAS^G12C-mutated GI cancers evaluated in this cohort, adagrasib was well-tolerated, with a manageable safety profile. Grade 3/4 treatment-related adverse events (TRAEs) were observed in 27% of patients treated with adagrasib, with no TRAEs leading to treatment discontinuation, and no Grade 5 TRAEs observed.

"We believe adagrasib has a differentiated molecular profile, and the data presented at ASCO GI further support its potential best-in-class profile," said Charles M. Baum, M.D., Ph.D., founder, president and head of research and development, Mirati Therapeutics, Inc. "The results demonstrated positive clinical activity in patients with KRAS^G12C-mutated GI cancers treated with single agent adagrasib, particularly in those with pancreatic cancer where options are limited. We continue to aggressively evaluate adagrasib as a single agent and in combination with other cancer medicines in a broad development plan to help more people living with cancer."

About Adagrasib (MRTX849)

Adagrasib is an investigational, highly selective, and potent oral small-molecule inhibitor of KRAS^G12C that is optimized to sustain target inhibition, an attribute that could be important to treat KRAS^G12C-mutated cancers, as the KRAS^G12C protein regenerates every 24−48 hours. Adagrasib is a being evaluated as monotherapy and in combination with other anti-cancer therapies in patients with advanced KRAS^G12C-mutated solid tumors, including non-small cell lung cancer (NSCLC), colorectal cancer and pancreatic cancer. For more information visit Mirati.com/science.

About Mirati Therapeutics, Inc.

Mirati Therapeutics, Inc. is a clinical-stage biotechnology company whose mission is to discover, design and deliver breakthrough therapies to transform the lives of patients with cancer and their loved ones. The company is relentlessly focused on bringing forward therapies that address areas of high unmet need, including lung cancer, and advancing a pipeline of novel therapeutics targeting the genetic and immunological drivers of cancer. Mirati is using its scientific expertise to develop novel solutions in two registration-enabling programs: adagrasib (MRTX849), an investigational small molecule, potent and selective KRAS^G12C inhibitor, as monotherapy and in combination with other agents, and sitravatinib, an investigational spectrum-selective inhibitor of receptor tyrosine kinases in combination with checkpoint inhibitor therapies. Mirati is also advancing its differentiated preclinical portfolio, including MRTX1133, an investigational KRAS^G12D inhibitor, MRTX1719, an investigational PRMT5 inhibitor, and other oncology discovery programs. Unified for patients, Mirati's vision is to unlock the science behind the promise of a life beyond cancer.

For more information about Mirati Therapeutics, visit us at Mirati.com or follow us on Twitter and LinkedIn.  

Forward Looking Statements

This press release contains forward-looking statements regarding the business of Mirati Therapeutics, Inc. ("Mirati"). Any statement describing Mirati's goals, expectations, financial or other projections, intentions or beliefs, development plans and the commercial potential of Mirati's drug development pipeline, including without limitation adagrasib (MRTX849), sitravatinib, MRTX1719 and MRTX1133, is a forward-looking statement and should be considered an at-risk statement. Such statements are subject to risks and uncertainties, particularly those challenges inherent in the process of discovering, developing and commercialization of new drug products that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such drugs.

Mirati's forward-looking statements also involve assumptions that, if they never materialize or prove correct, could cause its results to differ materially from those expressed or implied by such forward-looking statements. Although Mirati's forward-looking statements reflect the good faith judgment of its management, these statements are based only on facts and factors currently known by Mirati. As a result, you are cautioned not to rely on these forward-looking statements. These and other risks concerning Mirati's programs are described in additional detail in Mirati's quarterly reports on Form 10-Q and annual reports on Form 10-K, which are on file with the U.S. Securities and Exchange Commission (the "SEC") available at the SEC's Internet site (www.sec.gov). These forward-looking statements are made as of the date of this press release, and Mirati assumes no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those projected in the forward-looking statements, except as required by law. 

Mirati Contacts

Investor Relations: Temre Johnson | 858-332-3562 | ir@mirati.com 

Media Relations: Priyanka Shah | 908-447-6134 | media@mirati.com