- Pembrolizumab offered a significantly better objective response rate (ORR) than chemotherapy for patients with relapsed malignant pleural mesothelioma (MPM), but yielded no survival benefit.
Why this matters
- Single-agent chemotherapy is the standard of care for patients with MPM who experience relapse after platinum-based chemotherapy, but previous studies of immune checkpoint inhibitors had produced promising findings.
- International, randomized phase 3 PROMISE-meso trial.
- 144 patients with relapsed MPM received pembrolizumab (n=73) or chemotherapy (n=71).
- Funding: Merck, Sharpe & Dohme; Swiss Group for Clinical Cancer Research; others.
- All patients had received prior platinum-pemetrexed chemotherapy.
- ORR was significantly better with pembrolizumab (22% vs 6%; P=.004).
- At a median follow-up of 11.8 months, 88.9% in the pembrolizumab group and 92.9% in the chemotherapy group had discontinued treatment.
- No difference between groups in median PFS:
- 2.5 months for pembrolizumab vs 3.4 months for chemotherapy.
- HR, 1.06 (P=.76).
- Mortality was 65.8% in the pembrolizumab group vs 62.0% in the chemotherapy group.
- No difference between groups in median OS:
- 10.7 months for pembrolizumab vs 12.4 months with chemotherapy.
- HR, 1.12 (P=.59).
- No difference between groups in OS or PFS based on programmed death-ligand 1 expression.
- Open-label trial.