Mirati Therapeutics Presents Interim Clinical Data From Ongoing MGCD516 Phase 1 Dose Escalation Study In Patients With Advanced Solid Tumors

Mirati Therapeutics, Inc. ("Mirati")

, an oncology company focusing on genetic and epigenetic drivers of cancer, today announced it presented data from the study titled, "A First-in-Human Phase 1/1b Study of Receptor Tyrosine Kinase (RTK) Inhibitor, MGCD516, in Patients with Advanced Solid Tumors" at the 2015 European Cancer Congress (ECC) in Vienna, Austria. "The data we presented this weekend provide initial clinical evidence of MGCD516's safety and tolerability," said Charles M. Baum, president and CEO, Mirati. "MGCD516 is a potent, orally bioavailable inhibitor of certain RTKs reported to be key drivers of tumor growth. The favorable pharmacokinetics and tolerability of MGCD516 is encouraging and we look forward to starting the expansion cohort of the study in selected patients this year." MGCD516 is a potent RTK inhibitor that targets the RET, DDR and Trk tyrosine kinase signaling pathways, which are reported oncogenic drivers, as well as other signaling pathways that may play a role in tumor growth. This ongoing Phase 1, open label, single agent study is designed to evaluate the safety, pharmacokinetics/pharmacodynamics (PK/PD) and clinical activity of MGCD516 in unselected patients with advanced solid tumors, with an initial focus on non-small cell lung cancer (NSCLC). The objective of the dose escalation phase of the study, in unselected patients, is to characterize the safety of MGCD516, determine a Phase 2 dose and establish the maximum tolerated dose. MGCD516 is orally administered to unselected patients with advanced solid tumors once daily (QD) on a 21-day cycle. The study is exploring escalating doses of 10 mg, 20 mg, 40 mg, 80 mg, 110 mg, 150 mg and 200 mg, with twenty-eight patients enrolled to date. The 200 mg dose level is currently being evaluated. MGCD516 was well tolerated, with the most frequently reported adverse events (all grades, >25%) being fatigue, diarrhea, cough, hypertension, nausea and vomiting. The only dose limiting toxicity (DLT) seen to date was grade 3 Palmar-Plantar Erythrodysesthesia (Hand-Foot Syndrome) in one patient at the 80 mg dose. No DLTs were observed at the 110 mg and 150 mg doses. PK/PD data indicate MGCD516 is achieving serum levels associated with tumor inhibition seen in preclinical models. Next Steps The Company expects to initiate the Phase 1b dose expansion cohort of the MGCD516 trial in the fourth quarter of 2015. The dose expansion cohort will select for patients with genetic alterations in RET, DDR and Trk, and will also explore other mechanisms that may play a role in regulating tumor growth, including selecting for patients with CBL mutations and chromosome 4 amplicon alterations. The MGCD516 Phase 1 study poster presented at the ECC can be found on the Company's website at www.mirati.com. Additional information about this clinical trial of MGCD516 is available at www.clinicaltrials.gov using identifier: NCT02219711.