Dr. Lieu on Investigational Immunotherapy Strategies in mCRC

Christopher Lieu, MD, director, GI Medical Oncology Program and deputy associate director for clinical research, at the University of Colorado Cancer Center, discusses investigational immunotherapy strategies in metastatic colorectal cancer (mCRC).

The phase III IMblaze370 trial tested the combination of the MEK inhibitor cobimetinib (Cotellic) and the PD-L1 inhibitor atezolizumab (Tecentriq), versus atezolizumab alone or regorafenib (Stivarga) alone in the third-line setting. However, the trial was negative; there was no arm that did statistically significantly better than the others, says Lieu. Notably, the combination of cobimetinib and atezolizumab was not shown to be superior to regorafenib, which is the current standard of care.

An ongoing phase II trial at the University of Colorado is testing a similar strategy with MEK and PD-1 inhibition. In the trial, investigators are looking at the combination of the MEK inhibitor binimetinib (Mektovi), the VEGF inhibitor bevacizumab (Avastin), and the PD-1 inhibitor pembrolizumab (Keytruda) in patients with microsatellite stable CRC. Because this trial is still accruing, investigators will have to wait some time before the results are revealed.