The drug giant is seeking permission to expand the drug's uses to include first-line treatment of metastatic non-small-cell lung cancer (NSCLC) in patients whose tumours express EGFR mutations.
Osimertinib was granted Priority Review by the FDA.
The FDA has previously granted Tagrisso a breakthrough therapy designation in the first-line treatment of patients with metastatic EGFR mutation-positive non-small cell lung cancer, the company said. Patients with CNS metastases were allowed on the trial and all patients had exon 19 deletions or L858R mutations. Daily oral therapy was given with 80 mg of Tagrisso, 250 mg of Iressa, or 150 mg of Tarceva.
The PFS benefit with osimertinib extended across all prespecified subgroups. In patients with CNS metastases (116 patients), the median PFS with Tagrisso was 15.2 months compared with 9.6 months with standard therapy.
The objective response rate with osimertinib was 80% compared with 76% for erlotinib and gefitinib (odds ratio [OR], 1.28, 0.85-1.93; P =.2335). The median duration of response with osimertinib was 17.2 months versus 8.5 months in the comparator arm.
The most common all-grade adverse events (AEs) were diarrhea (58%) and dry skin (32%) in the experimental group compared with diarrhea (57%) and dermatitis acneiform (48%) in the control group. Data from FLAURA may position osimertinib as the standard of care for patients with EGFR-mutant NSCLC.
Osimertinib, a third-generation tyrosine kinase inhibitor (TKI) of EGFR, has shown improved efficacy over erlotinib and gefitinib - both EGFR TKIs - and activity against central nervous system (CNS) metastases.
The drug is already approved in several countries around the globe as a second-line treatment for patients with EGFR T790M mutation-positive advanced NSCLC.