FDA OKs Merck's Keytruda for colorectal cancer treatment

June 30, 2020

The U.S. Food and Drug Administration approved Keytruda (pembrolizumab) for intravenous injection for the first-line treatment of patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient colorectal (dMMR) cancer. This is the first immunotherapy approved for this patient population as a first-line treatment and which is administered to patients without also giving chemotherapy.

These types of tumors contain abnormalities that affect the proper repair of DNA inside the cell. Approximately 5% of patients with metastatic colorectal cancer have MSI-H or dMMR tumors.

"Metastatic colorectal cancer is a serious and life-threatening disease with a poor prognosis," said Richard Pazdur, M.D., director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research. "Pazdur says having a non-chemotherapy option available for patients is a noteworthy shift.

The FDA’s approval for this indication was based on the results of one multicenter, international, open-label, active-controlled, randomized trial that compared Keytruda with chemotherapy treatment in 307 patients with MSI-H or dMMR metastatic colorectal cancer. The study demonstrated a statistically significant improvement in progression-free survival (PFS) as assessed by blinded independent review. Median PFS was 16.5 months in the Keytruda group and 8.2 months in the standard of care group. Longer-term analysis is needed to assess for an effect on survival.

The FDA granted this application Priority Review. This review also used the Real-Time Oncology Review, which streamlines data submission prior to the filing of the entire marketing application, the Assessment Aid, a voluntary submission from the applicant to facilitate the FDA’s assessment of an application and Summary Level Review, which allows FDA to rely on qualified data summaries to support approval of a supplemental application.

Read the FDA release