The Food and Drug Administration has approved an expanded indication for Keytruda (pembrolizumab) for the first-line treatment of patients with unresectable or metastatic melanoma. Keytruda is a humanized monoclonal antibody that works by increasing the body's immune system to help fight and detect tumor cells; the drug blocks the interaction between anti-programmed death receptor-1 (PD-1) and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes, which may affect both tumor cells and healthy cells.
Keytruda, marketed by Merck, had previously received approval for the treatment of patients with advanced or unresectable melanoma who are no longer responding to other drugs (OT 10/10/14 issue); and the drug had previously received Priority Review designation for this newly approved indication in melanoma—first-line treatment of patients with unresectable or metastatic melanoma (OT 9/10/15 issue).
The drug has also received Breakthrough Therapy designation for the treatment of patients with microsatellite instability-high (MSI-H) metastatic colorectal cancer (OT 12/10/15 issue); another Priority Review designation for the treatment of patients with advanced non-small cell lung cancer (NSCLC) whose disease has progressed on or after platinum-containing chemotherapy and an FDA-approved therapy for EGFR or ALK genomic tumor aberrations, if present (OT 6/25/15 issue); and another Breakthrough Therapy designation for the treatment of patients with NSCLC that has progressed on or following platinum-based chemotherapy and that is also epidermal growth factor receptor (EGFR) mutation-negative and anaplastic lymphoma kinase (ALK) rearrangement-negative (OT 11/25/14 issue).
Approval for this new indication as first-line treatment is based on data from the KEYNOTE-006 Phase III study, data from which were presented at the most recent American Association for Cancer Research Annual Meeting (OT 6/10/15 issue). The trial evaluated 834 patients with unresectable or metastatic melanoma with progression of disease, randomized to receive Keytruda every three weeks or every two weeks, or ipilimumab, the standard of care.
Median progression-free survival for patients receiving Keytruda every three weeks was 5.5 months, compared with 4.1 months for those receiving Keytruda every two weeks, compared with 2.8 months for patients receiving ipilimumab. Patients receiving Keytruda every two or three weeks had a 42 percent reduction in the risk of disease progression or death compared with patients receiving ipilimumab.
The most common adverse events reported with treatment with Keytruda were fatigue, diarrhea, rash, and nausea. Severe adverse events were pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis.
Clinical Quick Facts: Keytruda
Drug: Keytruda (pembrolizumab)
Approved Indication: First-line treatment of patients with unresectable or metastatic melanoma
Serious Side Effects: Pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis
Common Side Effects: Fatigue, diarrhea, rash, and nausea