FDA approves Keytruda to treat small cell lung cancer

FDA has granted accelerated approval to pembrolizumab (Keytruda, Merck) for patients with metastatic small cell lung cancer (SCLC), marking the first indication for pembrolizumab in SCLC . Pembrolizumab is already an established treatment option for non-small cell lung cancer, with several approved indications for its use in the disease.

With this approval, pembrolizumab is now indicated for patients with metastatic SCLC with disease progression on or after platinum-based chemotherapy and at least 1 other prior line of therapy. This approval is based on tumor response rate and durability of response (DOR) as demonstrated in the KEYNOTE-158 and KEYNOTE-28 clinical trials

Patients in these trials evaluated for efficacy received either pembrolizumab 200 mg intravenously every 3 weeks or 10 mg/kg intravenously every 2 weeks. Among the 83 patients enrolled in the trials, 64% received 2 prior lines of therapy and 36% received 3 or more lines of therapy. Additionally, 60% received prior thoracic radiation therapy and 51% received prior radiation therapy to the brain. Overall, patients treated with pembrolizumab demonstrated an overall response rate (ORR) of 19% (95% CI, 11-29), with a complete response rate of 2% and a partial response rate of 17%. Of the 16 responding patients, 94% had a DOR of 6 months or longer, 63% had a DOR of 12 months or longer, and 56% had a DOR of 18 months or longer.