Pembrolizumab Beneficial for Advanced Small Cell Lung Cancer
Antitumor activity promising; objective response rate 19.3 percent for patients with incurable, advanced SCLC
TUESDAY, April 2, 2019 (Pharmacist'sd Briefing) -- For patients with advanced small cell lung cancer (SCLC), pembrolizumab shows antitumor activity with durable responses, according to a study presented at the annual meeting of the American Association for Cancer Research, held from March 29 to April 3 in Atlanta.
Hyun Cheol Chung, M.D., Ph.D., from the Yonsei Cancer Center in Seoul, South Korea, and colleagues presented outcomes for patients with confirmed incurable advanced SCLC enrolled in KEYNOTE-028 and KEYNOTE-158 who were receiving pembrolizumab after two or more lines of prior therapy. Pembrolizumab was administered for two years or until disease progression or intolerable toxicity. In both studies, the primary end point was objective response rate (ORR).
The researchers found that 83 of the 131 patients were eligible for efficacy analyses. The ORR was 19.3 percent. Two and 14 patients had a complete response and a partial response, respectively, per independent central review; of the responders, 14 were programmed death ligand 1-positive. The median duration of response was not reached. Sixty-one percent of the responders had a response lasting 18 months or more. Median progression-free survival (PFS) and median overall survival (OS) were 2.0 and 7.7 months, respectively. The 12-month rates for PFS and OS were 16.9 and 34 percent, respectively; the 24-month rates were 13.1 and 21 percent, respectively.
"Our study shows that pembrolizumab monotherapy can provide durable clinical benefit with manageable toxicity in this hard-to-treat patient population," Chung said in a statement.
Several authors disclosed financial ties to pharmaceutical companies, including Merck, which manufactures pembrolizumab and funded the study.