Pembrolizumab Approved With Chemotherapy for MPM

Pembrolizumab (Keytruda, Merck) has picked up another indication — this time for the first-line treatment of unresectable advanced or metastatic malignant pleural mesothelioma (MPM) in combination with pemetrexed and platinum chemotherapy.

With the US Food and Drug Administration’s September 17 approval, Merck’s blockbuster programmed cell death protein 1 (PD-1) inhibitor now has indications across 21 malignancies. Rival anti-PD-1 nivolumab (Opdivo, Bristol Myers Squibb) also carries a first-line indication for MPM in combination with ipilimumab, among many other indications.

Pembrolizumab’s new MPM approval was based on the KEYNOTE-483 trial, which randomized 440 patients to receive either pembrolizumab for up to 2 years in combination with pemetrexed and platinum-based chemotherapy for up to six cycles or pemetrexed and platinum-based chemotherapy for up to six cycles.

Median overall survival was 17.3 months with pembrolizumab add-on vs 16.1 months without it (hazard ratio, 0.79; 95% CI, 0.64-0.98; P = .0162). Median progression-free survival was 7.1 months in both arms.

Adverse reactions in the pembrolizumab arm were similar to those in other patients on pembrolizumab with pemetrexed and platinum chemotherapy, Merck said in a press release.

“Immune-mediated adverse reactions can occur at any time during or after treatment with KEYTRUDA…Based on the severity of the adverse reaction, KEYTRUDA should be withheld or permanently discontinued and corticosteroids administered if appropriate,” the company said. 

M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape Medical News. Alex is also an MIT Knight Science Journalism fellow. Email: [email protected].