- In unselected patients with malignant pleural mesothelioma (MPM) that progressed after prior chemotherapy, pembrolizumab does not improve progression-free survival (PFS) or overall survival (OS) with respect to single-agent chemotherapy.
- Pembrolizumab was associated with a significantly improved objective response rate (ORR).
- No new safety issues emerged with pembrolizumab.
Why this matters
- Malignant pleural mesothelioma (MPM) is an aggressive disease with poor prognosis.
- Single-agent chemotherapy is used in relapsed disease, but results in poor survival improvements.
- There is a need for new effective treatments in relapsed patients.
- In the open-label, phase 3 PROMISE-meso trial, 144 patients with advanced pre-treated mesothelioma were randomised to either pembrolizumab (n=73) or the participating centre’s choice of standard chemotherapy (n=71).
- Cross over to pembrolizumab was allowed at disease progression.
- Primary endpoint: PFS by blinded independent central review (BICR).
- Secondary endpoints: ORR, time to treatment failure (TTF), OS, investigator-assessed (IA) PFS, and adverse events (AEs).
- Correlative endpoint: outcomes by PD-L1 status.
- Funding: MSD.
- ORRs were 22% and 6% in pembrolizumab and chemotherapy groups, respectively (P=0.004).
- Median PFS by BICR was 3.4 months with chemotherapy and 2.5 months with pembrolizumab (HR=1.06, P=0.76).
- Median OS was 11.7 months with chemotherapy and 10.7 months with pembrolizumab (HR=1.05, P=0.85). 45 chemotherapy patients crossed over to pembrolizumab.
- Accounting for crossover led to similar OS results.
- 19% and 24% of patients experienced treatment-related AEs grade ≥3 in pembrolizumab and chemotherapy arms, respectively.
- “Although we did not see better survival with immunotherapy in the PROMISE-meso study, the responses are encouraging. We very much need better first- and second-line treatment for mesothelioma,” said Federica Grosso, Azienda Ospedaliera SS Antonio e Biagio e Cesare Arrigo, Alessandria, Italy, who was not involved in the study