Merck’s Keytruda Hits Coprimary Endpoint Early in MSI-H or dMMR Colorectal Cancer Trial

Merck’s Keytruda Hits Coprimary Endpoint Early in MSI-H or dMMR Colorectal Cancer Trial

Merck announced interim results from the Phase 3 KEYNOTE-177 trial evaluating first-line treatment of Keytruda in patients with microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) unresectable or metastatic colorectal cancer. Interim data shows the trial has reached the coprimary endpoint of improvement in progression free survival.

KEYNOTE-177 is a randomized, open-label evaluating Keytruda monotherapy versus standard of care chemotherapy for the first-line treatment of patients with MSI-H or dMMR advanced colorectal cancer. The study enrolled 308 patients. The dual primary endpoints are progression-free survival (PFS) and overall survival (OS); the secondary endpoint is ORR. Based on an interim analysis conducted by an independent Data Monitoring Committee (DMC), Keytruda monotherapy demonstrated a statistically significant and clinically meaningful improvement in one of its dual primary endpoints of progression-free survival (PFS) compared with chemotherapy (investigator’s choice of mFOLFOX6 or FOLFIRI, with or without bevacizumab or cetuximab). Based on the recommendation of the DMC, the study will continue without changes to evaluate overall survival (OS), the other dual primary endpoint. The safety profile of Keytruda in this trial was consistent with previously reported studies, and no new safety signals were identified.

About Colorectal Cancer
These cancers are referred to as colon cancer and rectal cancer depending on where the cancer starts. Colorectal cancer often begins with growths on the inner lining of the colon or rectum called polyps, which can change into cancer over time. Colorectal cancer is the third most commonly diagnosed cancer and the second most common cause of cancer-related death worldwide. It is estimated there were nearly 850,000 new cases of colorectal cancer and more than 880,000 deaths from the disease globally in 2018. In the United States, it is estimated there will be nearly 105,000 new cases of colon cancer and more than 43,000 new cases of rectal cancer, resulting in more than 53,000 deaths from colorectal cancer in 2020. The five-year survival rates for advanced/metastatic colon cancer and rectal cancer (stage IV) are estimated to be 14% and 15%, respectively.

About Keytruda (pembrolizumab) Injection, 100 mg
Keytruda is an anti-PD-1 therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. Keytruda is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.