Benzinga | Sep 18, 2020 08:01AM EDT

Mirati Therapeutics Highlights Presentation Of Phase 2 Data On Sitravatinib In Combo With Nivolumab In Urothelial Cancer At European Society For Medical Oncology Sept. 19-21

Mirati Therapeutics, Inc. (NASDAQ:MRTX), a clinical-stage targeted oncology company, today announced updated clinical results from its Phase 2 study evaluating sitravatinib in combination with nivolumab (OPDIVO(r)) in patients with advanced or metastatic urothelial carcinoma. Sitravatinib is an investigational multi-targeted tyrosine kinase inhibitor that distinguishes itself by potently targeting the TAM (TYRO3, Axl, Mer) and split (VEGFR2, KIT) family receptors. The combination of sitravatinib with nivolumab demonstrated promising clinical activity in checkpoint inhibitor-na?ve, platinum-refractory patients. These data were presented today in a mini oral session at the European Society for Medical Oncology Virtual Congress (ESMO) 2020 by Dr. Pavlos Msaouel, M.D., Ph.D.

The ongoing, Phase 2, open-label, multicenter trial in patients with advanced or metastatic urothelial carcinoma includes multiple patient cohorts that are defined based on prior therapy and platinum eligibility. Participants in the cohort updated today had been previously treated with platinum-containing chemotherapy but were checkpoint inhibitor na?ve.

As of the data cut-off on July 30, 2020, 30 out of 40 patients enrolled in this checkpoint inhibitor-na?ve, platinum-experienced cohort of the Phase 2 study were evaluable for response:

* Findings showed an objective response rate of 37%, with 1 patient achieving a complete response (CR) and 10 patients achieving a partial response (PR: 8 confirmed, 2 unconfirmed) in this high-risk population (based on prognostic factors and baseline disease sites)

* 22/30 (73%) patients achieved clinical benefit (combination of CR plus PR plus stable disease)

* Secondary efficacy endpoints continue to mature with a median follow-up of 8.7 months

"These data indicate that sitravatinib in combination with nivolumab resulted in a higher overall response rate, as well as longer preliminary progression free survival, when compared to what is generally seen with checkpoint inhibitors or similar tyrosine kinase inhibitor monotherapies in this setting," said Pavlos Msaouel, M.D., Ph.D., Assistant Professor, Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas. "These data continue to show activity of the combination in this tumor setting and further demonstrate the ability of sitravatinib to augment the clinical activity of checkpoint inhibitors. We're pleased by the strength of the combination response, and as the data mature over time, we will continue to evaluate the duration of response."

The sitravatinib and nivolumab combination has been well-tolerated and consistent with what has been previously reported in urothelial carcinoma and across other tumor settings.

The primary objective of the trial is to evaluate clinical activity as measured by objective response rate. Secondary objectives include evaluation of safety, tolerability, efficacy (including duration of response, clinical benefit rate, progression free survival and overall survival), and pharmacokinetics.