ESMO 2019 — Relapsed mesothelioma: similar survival outcomes with pembrolizumab and chemotherapy

  • Cristina Ferrario — Agenzia Zoe
  • Oncology Conference reports
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  • 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.

Study design

  • 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.

Key results

  • 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.

Expert commentary

  • “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