Ryan B. Corcoran, MD, PhD, commented on the C-800 study for The ASCO Post. Dr. Corcoran is the Mark J. Kusek Endowed Chair in Colorectal Cancer, Director of the Gastrointestinal Cancer Center Program and Scientific Director of the Termeer Center for Targeted Therapy, Massachusetts General Hospital Cancer Center, and Associate Professor of Medicine at Harvard Medical School.

“To date, the benefit of immunotherapy in metastatic colorectal cancer has been restricted to the roughly 4% of patients with microsatellite instability. By contrast, immune checkpoint inhibitors have been largely ineffective in microsatellite-stable [MSS] colorectal cancer. Even with combined immune checkpoint inhibitors targeting PD-1 and CTLA-4, response rates have typically been between 0% and 10%,” Dr. Corcoran noted.

Ryan B. Corcoran, MD, PhD

“In this study, using an anti–PD-1 antibody in combination with a modified CTLA-4 antibody, … a 24% overall response rate was observed in 42 patients with metastatic MSS colorectal cancer, which compares favorably with previous immunotherapy studies. Moreover, the investigators found that responses were observed primarily in patients without active liver metastases, with a 42% response rate in this group, which might provide a tractable patient enrichment strategy,” Dr. Corcoran said. “Overall, the data support further investigation of these agents in MSS colorectal cancer.” 

DISCLOSURE: Dr. Corcoran has received consulting fees from AbbVie, Array Biopharma/Pfizer, Asana Biosciences, Astex Pharmaceuticals, Avidity Biosciences, BMS, C4 Therapeutics, Cogent Biosciences, Elicio, Erasca, Fog Pharma, Guardant Health, Ipsen, Kinnate Biopharma, Mirati Therapeutics, Natera, Navire, Nested Therapeutics, N-of-one/Qiagen, nRichDx, Remix Therapeutics, Revolution Medicines, Roivant, Syndax, Taiho, Tango Therapeutics, Theonys, and Zikani Therapeutics; has served on advisory boards and holds equity with Avidity Biosciences, C4 Therapeutics, Cogent Biosciences, Erasca, Kinnate Biopharma, Interline Therapeutics, Nested Therapeutics, nRichDx, Remix Therapeutics, Revolution Medicines, and Theonys; and is cofounder/served on advisory board/board of directors/holds equity with Alterome Therapeutics.