Treatment with the programmed death-1 (PD-1) inhibitor nivolumab significantly improves overall and progression-free survival in patients with relapsed malignant mesothelioma, a study shows.

The CONFIRM phase 3 trial enrolled 332 adults with previously treated, unresectable malignant mesothelioma and Eastern Co-operative Oncology Group performance status of zero to one.

Patients were stratified by epithelioid and non-epithelioid history and randomly allocated to nivolumab (240mg on a 14-day cycle, 221 patients) or placebo (111 patients), administered until progression, unacceptable toxicity, withdrawal or 12 months.

While the overall survival data were immature, with only 232 of a target of 291 events, patients lived significantly longer on nivolumab than placebo (median 9.2 vs 6.6 months), delegates at the International Association for the Study of Lung Cancer virtual World Conference on Lung Cancer were told.