Keytruda Receives New Indication for Metastatic Small-Cell Lung Cancer After Disease Progression
On June 17, 2019, the FDA granted accelerated approval to pembrolizumab (Keytruda; Merck) monotherapy for the treatment of patients with metastatic small-cell lung cancer whose disease progressed during or after platinum-based chemotherapy and at least 1 previous therapy. The FDA granted this application a priority review, making it the fifth FDA approval this year for pembrolizumab.
This new indication was based on data from 83 patients with small-cell lung cancer whose disease progressed during or after ≥2 previous therapies and were enrolled in the multicenter, nonrandomized, open-label KEYNOTE-158 or KEYNOTE-028 clinical trials.
Treatment with pembrolizumab continued until disease progression, unacceptable toxicity, or a maximum of 24 months. Overall response rate (ORR) and duration of response were the primary end points.
The ORR was 19% (95% confidence interval, 11-29), including 2% complete responses and 17% partial responses. Of the 16 responding patients, 15 (94%) sustained a response for ≥6 months. The responses were durable for ≥12 months in 10 (63%) patients and for ≥18 months in 9 (56%) patients.
The safety profile in this study was similar to that seen in other studies with pembrolizumab monotherapy. A total of 9% of patients discontinued treatment because of adverse events, and 25% of the patients had at least 1 dose of pembrolizumab withheld because of an adverse reaction. Serious adverse events were reported in 31% of patients, most often (≥2%) pneumonia and pleural effusion.