The initial clinical results of Mirati combination therapy were positive

, Mirati Therapeutics published preliminary clinical data on its use in the study of protein kinase inhibitor sitravatinib in association with the anti-PD-1 antibody nivolumab to treat patients with advanced renal transparent cell carcinoma (aCCRCC) in Phase 1/2 clinical trials. Preliminary efficacy data show that this combination therapy achieves a 92% disease control rate in this group of patients.Immune checkpoint inhibitors, represented by PD-1/PD-L1 inhibitors, have produced significant results in many types of cancer patients since their inception. But only about 20 percent of patients benefit from these treatments. For patients who develop resistance to PD-1/PD-L1 inhibitors, their treatment options remain very limited. Therefore, how to improve the effectiveness of cancer immunotherapy is the focus of research and development in this field.The Sitravatinib, developed by Mirati, is a genealogically selective oral-accepted tyrosine kinase (RTK) inhibitor. It suppresses several similar RTKs, including TAM (Tyro3/Axl/MERTK), VEGFR2 and KIT. These RTKs play an important role in creating a tumor micro-environment with immunosuppressive function.By inhibiting these RTKs, sitravatinib can play a variety of roles in regulating the immune system, including converting immunosuppressive M2 macrophages into M1 macrophages, expanding the number of CD8-positive T-cells, and reducing the number of regulatory T-cells (Treg) and myelin-inhibiting cells (MDSCs) with immunosuppressive ability, thus overcoming resistance to checkpoint inhibitors.In this Phase 1/2 clinical trial, as of January 1, 2020, 38 patients were treated for more than 12 weeks and could be evaluated. These patients had received targeted veGF therapy, but the disease continued to progress. Preliminary trial results showed that 15/38 (39%) patients received confirmed partial remission (PR), with one PR patient further improving to unrefirmed full remission (CR) 35/38 (92%) patient disease control (disease stabilization plus PR plus PR) CR)The initial medium non-progression lifetime (PFS) is 10.3 monthsthe medium total lifetime (OS) has not yet been reached (the medium follow-up period is 17.7 months), and as of January 1 this year, 79% of patients are still receiving treatment.Preliminary results from Phase 1/2 clinical trials show encouraging and lasting relief from sitravatinib combination therapy compared to nivolumab monotherapy," said Dr. Charles M. Baum, President and CEO of Mirati. " (Drug Mingkang)