MSD’s Keytruda has significantly increased overall survival in patients with lung cancer expressing any level of PD-L1 when used as monotherapy in the first-line setting, potentially significantly increasing the drug’s treatment scope.

The Phase III KEYNOTE-042 trial assessed the anti-PD-1 therapy in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC).

An interim analysis showed that treatment with Keytruda (pembrolizumab) resulted in significantly longer overall survival than platinum-based chemotherapy in patients with a PD-L1 tumor proportion score (TPS) of ≥1 percent.

Keytruda remains the only anti-PD-1 approved as monotherapy for NSCLC in the first-line setting, though initial approval was for its use in patients with a TPS of more than 50 percent. Widening the indication to include patients with any level of PD-L1 expression would thus substantially widen the target population.

“Improvement in overall survival is the ultimate objective in the treatment of advanced lung cancer. KEYNOTE-042 is the first randomised Phase III study of a single-agent immunotherapy using overall survival as the primary endpoint that has demonstrated significant benefit as first-line therapy in NSCLC patients who tested positive for PD-L1 at 1 percent or higher,” said Dr Tony Mok, professor in the Department of Clinical Oncology at the Chinese University of Hong Kong.

The trial will continue to evaluate progression-free survival (PFS), a secondary endpoint, and trial results will be submitted to regulatory authorities worldwide, the firm noted.