Eng C, et al. - In IMblaze 370, a phase 3 trial performed at 73 academic medical centers and community oncology practices in 11 countries, researchers compared atezolizumab plus cobimetinib or atezolizumab monotherapy vs regorafenib in the third-line setting among patients (aged at least 18 years) with unresectable locally advanced or metastatic colorectal cancer. These subjects had baseline Eastern Cooperative Oncology Group performance status of 0-1, and progression of disease on or intolerance to at least two previous systemic chemotherapy regimens. The overall survival in the intention-to-treat population was the primary endpoint. With atezolizumab plus cobimetinib or atezolizumab vs regorafenib, the primary endpoint was not met. The safety profile of atezolizumab plus cobimetinib was found to be in line with those of the individual drugs. Expansion of the benefit of immunotherapy to patients whose tumors have lower baseline levels of immune inflammation, such as those with microsatellite-stable metastatic colorectal cancer, is challenging.