The United States Food and Drug Administration (FDA) has approved an additional indication for the agent Keytruda® (pembrolizumab) to become the first-ever approved agent based specifically on a patient’s genetic mutations, not type of cancer.
Specifically, pembrolizumab was approved for “adult and pediatric patients with unresectable or metastatic, microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options or with MSI-H or dMMR colorectal cancer that has progressed following treatment with a fluoropyrimidine, oxaliplatin, and irinotecan.” The FDA announced that this is its “first tissue/site-agnostic approval.”
Solid tumors refer to any type of cancer that is not of blood or lymph origin; MSI-H and dMMR refer to types of mutations within the cancer cells.
This approval was based on 5 clinical trials including 149 patients with MSI-H or dMMR cancers, 90% of whom had colorectal cancer, while the remaining 10% were diagnosed with one of 14 other types of cancers. Patients were treated with different doses and schedules of pembrolizumab.
- Overall rates of anti-cancer responses were achieved in nearly 40% of patients.
- Among patients who achieved an anti-cancer response with pembrolizumab, nearly 80% had responses that lasted at least 6 months or longer.
- 11 patients achieved a complete disappearance of detectable cancer with pembrolizumab, and 48 patients achieved a significant reduction in size of their cancer.
- The most common side effects associated with pembrolizumab included fatigue, rash, itching and diarrhea.
The FDA granted pembrolizumab this indication under an expedited review and accelerated approval process, which will require further studies to confirm the benefit of pembrolizumab in these settings. However, this approval represents a large step forward in a changing of the treatment paradigm for patients with cancer.
Reference: United States Food and Drug Administration (FDA). FDA grants accelerated approval to pembrolizumab for first tissue/site agnostic indication. Accessed May 25, 2017. Available at: https://www.fda.gov/drugs/informationondrugs/approveddrugs/ucm560040.htm.