Dr. Corcoran on Immunotherapy for Microsatellite Stable/Instable CRC

Ryan B. Corcoran, MD, PhD, associate professor, Cancer Center, Massachusetts General Hospital, assistant professor of medicine, Harvard Medical School, discusses immunotherapy options for patients with microsatellite stable versus microsatellite instability (MSI)—high (MSI-H) colorectal cancer (CRC).

Generally, patients with CRC do not respond well to checkpoint inhibitors, says Corcoran. However, a subset of 4% to 5% of these patients with MSI-H or mismatch repair deficiency derive significant improvement from these agents, due to the high level of mutations the immune system can recognize.

For the remaining 96% of patients, Corcoran says extensive exploration is being done with immunotherapy agents to extend the immunogenicity benefit seen in MSI-H tumors.

Checkpoint inhibitors in combination with radiation, targeted agents, and bispecific antibodies, which engender an immune response, are currently under investigation, concludes Corcoran.