FDA grants accelerated approval for Keytruda (pembrolizumab) to treat squamous and non squamous NSCLC- Merck

Merck announced that on 2 October 2015, the FDA approved Keytruda (pembrolizumab) monotherapy, at a dose of 2 mg/kg every three weeks, for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumours express PD-L1 (as determined by an FDA-approved test) and who have disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumour aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving pembrolizumab.

Under FDA’s accelerated approval regulations, this indication for pembrolizumab is approved based on tumour response rate and durability of response. An improvement in survival or disease-related symptoms has not yet been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.

In parallel with the approval of pembrolizumab, the FDA has also given Pre-Market Approval (PMA) to the first predictive companion diagnostic for use in detecting PD-L1, an immune-related biomarker expressed on some tumour cells: the PD-L1 IHC 22C3 pharmDx kit made by Dako North America, an Agilent Technologies Company. The data supporting the approval of Keytruda for metastatic NSCLC showed that 22 percent of patients (n=61/280) had a PD-L1 TPS greater than or equal to 50%.

Comment: pembrolizumab is the first and only anti-PD-1 (programmed death receptor-1) therapy approved for both squamous and non-squamous metastatic NSCLC. Other PD antagonists in competition are Opdivo (nivolumab) from BMS approved in March 2015 for squamous NSCLC, atezolizumab (MPDL 3280A) from Roche and MEDI 4736 from Medimmune/AstraZeneca, both in Phase III trials.