Mirati Therapeutics Reports Fourth Quarter And Full-Year 2017 Financial Results

SAN DIEGO, March 8, 2018

"We made significant progress in our key programs in 2017," said Charles M. Baum, M.D., Ph.D., President and Chief Executive Officer. "Promising data from the sitravatinib and KRAS programs encouraged us to pursue a more aggressive approach to accelerate development, supported by the successful financing we completed in November. In early 2018, we initiated a strategic regional partnership with BeiGene Ltd. that we anticipate will rapidly expand the development of sitravatinib in multiple tumor types. We expect to report multiple key catalysts in 2018, including a mid-year clinical update for our sitravatinib program. Our KRAS inhibitor program, an important yet elusive target, is growing and we remain on track for an IND filing in the fourth quarter of 2018."

Recent Corporate Highlights

• Sitravatinib clinical data presented at 2017 IASLC World Conference on Lung Cancer
• Combination of sitravatinib and nivolumab in non-small cell lung cancer (NSCLC) patients with documented progression following checkpoint inhibitor therapy demonstrated 3 confirmed Partial Responses in first 11 evaluable patients
• First evaluable NSCLC patient with CBL inactivating mutation treated with single agent sitravatinib demonstrated confirmed Partial Response with 77% tumor reduction
• KRAS G12C lead candidates selected and advanced into IND-enabling development activities
• Significant achievement in development of a direct inhibitor of KRAS, a well-known but previously undruggable cancer mutation
• A potentially transformational, first-in-class treatment for 14% of NSCLC and 5% of colorectal cancer patients
• Program is on track to advance to IND filing in the fourth quarter of 2018
• Exclusive license agreement initiated with BeiGene Ltd. for the development, manufacture and commercialization of sitravatinib in Asia (excluding Japan), Australia and New Zealand
• Expected to accelerate development of sitravatinib in NSCLC as well as other key indications including bladder, renal and hepatocellular cancer
• $86.7M public offering completed in November 2017; $150.8M of cash, cash equivalents and short-term investments as of December 31, 2017

Fourth Quarter and Full Year Financial Results

Cash, cash equivalents, and short-term investments were $150.8 million on December 31, 2017, as compared to $56.7 million on December 31, 2016.

Research and development expenses for the fourth quarter of 2017 were $15.2 million, compared to $16.0 million for the same period in 2016. Research and development expenses for the year ended December 31, 2017 were $58.1 million, compared to $68.5 million for the same period in 2016. The decrease in research and development expenses for both periods is primarily due to a reduction in glesatinib expenses and a reduction in share-based compensation expense.  These decreases are partially offset by increases in expenses associated with our ongoing sitravatinib clinical trials.

General and administrative expenses for the fourth quarter of 2017 were $3.0 million, compared to $3.9 million for the same period in 2016. General and administrative expenses for the year ended December 31, 2017 were $13.5 million, compared to $15.3 million for the same period in 2016. The decrease in general and administrative expense for both periods is primarily due to a decrease in share-based compensation expense.