Pembrolizumab's Breakthrough Toughens the Playing Field in NSCLC

The FDA has accepted for priority review the supplemental Biologics License Application for pembrolizumab (Keytruda), Merck’s programmed death-1 (PD-1) inhibitor antibody. The application, which includes phase 3 data from the KEYNOTE-024 study, seeks approval for using pembrolizumab as first-line treatment in patients diagnosed with programmed death ligand-1 (PD-L1)—expressing advanced non-small cell lung cancer (NSCLC).

Back in June, the company disclosed that an independent Data Monitoring Committee had recommended that the trial be stopped early since it had met its primary endpoint of progression-free survival (PFS) and secondary endpoint of overall survival (OS). The pembrolizumab monotherapy improved both PFS and OS when compared with standard chemotherapy in treatment-naïve patients with advanced NSCLC whose tumors expressed high levels of PD-L1.

“Chemotherapy has been the foundation of first-line treatment for non-small cell lung cancer for decades, so the significant improvement in survival in patients with high PD-L1 expression seen with Keytruda compared to chemotherapy is welcome news,” said Roger M. Perlmutter, MD, PhD, president, Merck Research Laboratories. “We appreciate the opportunity to work with regulatory authorities to make Keytruda a first-line treatment option in non-small cell lung cancer,” he added.

Today’s announcement comes a week after Roche announced positive results from phase 3 studies evaluating its PD-L1 antibody atezolizumab (Tecentriq), which improved OS in patients with locally advanced or metastatic NSCLC who had progressed on platinum-based chemotherapy, compared with docetaxel.

The field of immuno-oncology is witnessing stiff competition among the top 3 drug developers: Bristol-Myers Squibb (BMS), Merck, and Roche. While nivolumab (Opdivo) has been the market leader thus far, BMS suffered a setback recently when the results of the Checkmate-026 trial were released. Nivolumab, the trial results showed, failed to improve PFS when administered as a monotherapy in treatment-naïve patients with NSCLC whose tumors express at least 5% of PD-L1.

Currently, pembrolizumab is approved for treatment of patients with unresectable or metastatic melanoma, patients with PD-L1—expressing NSCLC who have progressed on platinum-based chemotherapy, and patients with advanced head and neck squamous cell carcinoma who have progressed on platinum-based chemotherapy.