Integrating Advances in Immunotherapy into Treatment of mCRC in the Community

Heinz-Josef Lenz, MD, professor of medicine and preventive medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, discusses the advances in immunotherapy for the treatment of patients with metastatic colorectal cancer (mCRC).

In mCRC, oncologists have come a long way with integrating immunotherapy into treatment. Over the years, oncologists have also figured out that tumors with microsatellite instability are sensitive to immune checkpoint blockade. Lenz says this was seen in clinical trials using pembrolizumab (Keytruda) and nivolumab (Opdivo), which showed that DNA mismatch repair-deficient refractory tumors have significant response rates when PD-1/PD-L1 blockade was used.

Response rates were over 50%, says Lenz, and once data were released, physicians began to wonder if chemotherapy was necessary if these immunotherapy agents could achieve such responses. This question leads to the testing of immune blockade with either PD-1/PD-L1 inhibition alone or PD-1/PD-L1 inhibition in combination with CTLA-4 inhibition in the first-line setting.