Mirati Therapeutics, Inc. (NASDAQ: MRTX), a clinical-stage targeted oncology company, announced data from the ongoing Phase 2 clinical trial of mocetinostat in combination with durvalumab (IMFINZI®) in non-small cell lung cancer (NSCLC) patients at the Society for Immunotherapy of Cancer (SITC) 33rd Annual Meeting in Washington, D.C. The data will be presented today in a poster and also in an oral presentation on Sunday, November 11th.
Highlights from the Oral Presentation
The clinical trial is a Phase 2 study evaluating the efficacy and safety of mocetinostat in combination with durvalumab, an anti-PD-L1 immune checkpoint inhibitor, in patients with NSCLC who have experienced documented disease progression following prior treatment with an immune checkpoint inhibitor. As of the data cut-off date of October 2, 2018:
29 patients were evaluable for response with at least one radiographic scan. Patients had a median of two lines of previous therapy.
12/29 evaluable patients demonstrated tumor reductions.
6/29 evaluable patients demonstrated tumor reductions of greater than 30%.
5/29 evaluable patients achieved a confirmed Partial Response (PR).
4/29 evaluable patients, including 2 responding patients, remained on treatment at the time of data cut-off.
A preliminary Kaplan-Meier estimate of median duration of response was greater than 5 months.
The combination has been well-tolerated and most adverse events (AEs) were grade 1 or 2.
"The combination of mocetinostat with durvalumab demonstrated clinical benefit in this difficult to treat population of checkpoint inhibitor refractory NSCLC patients," said Charles Baum, M.D., Ph.D., President and Chief Executive Officer at Mirati Therapeutics. "While these results are promising, we have made the strategic portfolio decision to prioritize sitravatinib for further development in the treatment of checkpoint inhibitor refractory patients and plan to explore collaborative opportunities to further develop mocetinostat."
The Company recently announced plans to initiate a Phase 3 clinical trial comparing sitravatinib in combination with checkpoint inhibitor therapy to docetaxel in second line checkpoint inhibitor refractory NSCLC patients in the first half of 2019. In addition, the Company also announced plans to initiate a Phase 1/2 clinical trial of MRTX849, an oral inhibitor of KRAS G12C, in patients with NSCLC, colorectal cancer, and other solid tumors that harbor the G12C mutation. Trial initiation is planned for early 2019 after the investigational new drug (IND) allowance letter is received from the U.S. Food and Drug Administration (FDA) for the application that was filed in October 2018.
Mocetinostat is an oral, Class I and IV selective histone deacetylase (HDAC) inhibitor. Inhibition of histone acetylation is predicted to enhance the recognition of tumor cells by anti-tumor T cells and reverse immunosuppressive factors in the tumor microenvironment. Mocetinostat is being evaluated in a Phase 2 clinical trial in combination with durvalumab (IMFINZI®) in non-small cell lung cancer (NSCLC) patients who have experienced disease progression following prior treatment with a checkpoint inhibitor.