SAN DIEGO,/ -- Mirati Therapeutics, Inc. (NASDAQ: MRTX), a clinical stage targeted oncology company, announced today that it has submitted an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) to initiate a Phase 1/2 trial with the initial goal to evaluate safety, tolerability and pharmacokinetics of the Company's KRAS G12C inhibitor, MRTX849, in patients with advanced solid tumors. The trial will utilize an accelerated titration design with single patient cohorts and intra-patient dose escalation to rapidly achieve an active dose level for MRTX849. Phase 2 expansion cohorts will enroll patients whose tumors are driven by KRAS G12C positive mutations. The Phase 2 portion of the trial in patients with non-small cell lung cancer (NSCLC) or colorectal cancer (CRC) may provide proof of concept and the basis for accelerated approval. "MRTX849, is a potent, highly selective inhibitor of G12C positive mutations. These mutations occur in large patient populations with NSCLC and CRC tumors, and are also present in patients with other solid tumors, such as pancreatic cancer. We submitted the IND on October 29^th, 2018 and plan to begin enrolling patients soon after FDA approval is received. The trial is designed to enable early clinical efficacy data in 2019," said Charles Baum, M.D., Ph.D., President and Chief Executive Officer, Mirati Therapeutics, Inc. "KRAS has long been one of the most difficult targets in all of oncology and this program has the potential to be a breakthrough for patients with G12C positive mutations." "KRAS has been an elusive target for researchers for more than 30 years. It's exciting to see an IND filing that would potentially provide a therapy for patients with G12C mutations, which were once considered undruggable and who have had no viable treatment options," said Channing J. Der, Ph.D., the Sarah Graham Kenan Professor of Pharmacology at the University of North Carolina at Chapel Hill Lineberger Comprehensive Cancer Center. About MRTX849 MRTX849 is an orally-available small molecule that potently and selectively inhibits a form of KRAS which harbors a substitution mutation (G12C). KRAS G12C mutations are present in approximately 14% of NSCLC adenocarcinoma patients and 5% of colorectal cancer patients.?Tumors characterized by KRAS G12C mutations are commonly associated with poor prognosis and resistance to therapy, and patients with these mutations have few treatment options. MTRX849 has demonstrated broad-spectrum tumor regression in a large cohort of KRAS G12C-positive pre-clinical in-vivo human tumor models. MRTX849 demonstrated complete regression of tumors in a subset of models at well-tolerated dose levels. Early proof-of-concept clinical data is anticipated in 2019. About Mirati Therapeutics Mirati Therapeutics, Inc. is a clinical-stage oncology company developing product candidates to address the genetic, epigenetic and immunological promoters of cancer. Our precision oncology clinical programs utilize next-generation genomic testing to identify and select cancer patients who we believe would be most likely to benefit from targeted drug treatment. In immuno-oncology, we are advancing clinical programs where our product candidates have the potential to improve the immune environment of tumor cells and may enhance and expand the efficacy of existing cancer immunotherapy medicines when given in combination. Our pre-clinical programs include potentially first-in-class and best-in-class product candidates specifically designed to address mutations and tumors where few treatment options exist. We approach each of our discovery and development programs with a singular focus: to translate our deep understanding of the molecular drivers of cancer into better therapies and better outcomes for patients. For more information, visit www.mirati.com. Forward Looking Statements This press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Any statements in this press release regarding the business of Mirati Therapeutics, Inc. ("Mirati") that are not historical facts may be considered "forward-looking statements," including without limitation statements regarding Mirati's development plans and timelines, potential regulatory actions, expected use of cash resources, the timing and results of clinical trials, and the potential benefits of and markets for Mirati's product candidates. Forward-looking statements are typically, but not always, identified by the use of words such as "may," "will," "would," "believe," "intend," "plan," "anticipate," "estimate," "expect," and other similar terminology indicating future results. Forward-looking statements are based on current expectations of management and on what management believes to be reasonable assumptions based on information currently available to them, and are subject to risks and uncertainties. Such risks and uncertainties may cause actual results to differ materially from those anticipated in the forward-looking statements. Such risks and uncertainties include without limitation potential delays in development timelines, negative clinical trial results, reliance on third parties for development efforts, changes in the competitive landscape, changes in the standard of care, as well as other risks detailed in Mirati's recent filings on Forms 10-K and 10-Q with the U.S. Securities and Exchange Commission. Except as required by law, Mirati undertakes no obligation to update any forward-looking statements to reflect new information, events or circumstances, or to reflect the occurrence of unanticipated events.