The checkpoint antibody Keytruda has been approved as a first-line treatment for a certain type of metastatic colorectal cancer, bringing the number of US cancer indications for the drug up to 28. The approval was based on the results of a Phase 3 trial in which Keytruda was shown to reduce the risk of disease progression or death by 40% compared with chemotherapy, the current standard of care. Patients in the trial had metastatic microsatellite instability-high or mismatch repair deficient colorectal cancer.
