Dr. Overman Discusses Progress With Immunotherapy in GI Cancer

Michael J. Overman, MD, associate professor, Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, discusses progress made with immunotherapy agents in gastrointestinal (GI) cancer.

CTLA-4 is an immune checkpoint inhibitor under investigation in GI cancer, says Overman. Several studies have examined combination therapies that target PD-L1 and CTLA-4, most notably, nivolumab (Opdivo) and ipilimumab (Yervoy). In July 2018, the FDA granted an accelerated approval to the immunotherapy combination for the treatment of adult and pediatric patients 12 years and older with microsatellite instability-high or mismatch repair deficient metastatic colorectal cancer following progression on a fluoropyrimidine, oxaliplatin, and irinotecan.

The combination demonstrated a 49% (95% CI, 39-58) overall response rate. Of the 58 patients who responded to the combination, 5 achieved a complete response and 53 achieved a partial response. At the time of the approval, the median duration of response had yet to be reached (range, 1.9-23.2+ months), with 83% of responders showing a sustained response ≥ 6 months.