US regulators have approved a combination of Eli Lilly’s Alimta and MSD’s Keytruda as first-line treatment for patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), irrespective of PD-L1 expression status.

The combination was approved via the US Food and Drug Administration’s accelerated approval pathway based on Phase II tumour response rate and progression-free survival (PFS) data observed in a cohort of Merck's KEYNOTE-021 study, and so its clinical benefit may still need to be verified in confirmatory trials.

In the trial, the combination of Alimta (pemetrexed), carboplatin and Keytruda (pembrolizumab) showed a statistically significant improvement in objective response rate (ORR) versus Alimta plus carboplatin alone (55 percent vs 29 percent), while median progression free survival came in at 13.0 months and 8.9 months, respectively.

Lilly notes that this is the first and only combination of chemotherapy and immunotherapy to earn FDA approval for the first-line treatment of metastatic nonsquamous NSCLC.

"Lung cancer is the leading cause of cancer death in the US, and this approval represents the power of rational combinations and collaborations in bringing new treatments to these patients," said Sue Mahony, senior vice president and president of Lilly Oncology.

The combination is also under review in Europe, where its submission also includes data from the Phase III Keynote-189 trial, which showed that its first-line use slashed the risk of death by 51 percent compared with chemotherapy alone.