Lung cancer is one of a handful of solid tumors that have seen outcomes improve with the use of immune checkpoint inhibitors. Nivolumab and pembrolizumab, PD-1 inhibitors, and the PD-L1 inhibitor, atezolizumab, are already approved by the US Food and Drug Administration (FDA) for patients with previously treated advanced non–small cell lung cancer (NSCLC). Durvalumab, another PD-L1 inhibitor, may be next.
Like atezolizumab, durvalumab targets PD-L1, blocking any PD-L1 interaction with PD-1 and CD80 on T cells and consequently inducing an immune response. In July, the FDA granted durvalumab breakthrough therapy designation for patients with locally advanced unresectable NSCLC whose disease had not progressed after platinum-based chemoradiation.1
The designation was based on interim results from the phase 3 PACIFIC trial (ClinicalTrials.gov Identifier: NCT02125461), which evaluated durvalumab as a sequential treatment among these patients. The trial randomly assigned 713 patients 2:1 to durvalumab 10 mg/kg or placebo every 2 weeks for up to 12 months.
In October, the FDA granted durvalumab priority review after the full results of PACIFIC were presented at the European Society for Medical Oncology (ESMO) 2017 Congress in Madrid and published in The New England Journal of Medicine.2 The updated results showed that durvalumab significantly prolonged progression-free survival (PFS) compared with placebo.
The median PFS for durvalumab was triple that of placebo, at 16.8 months compared with 5.6 months, respectively (hazard ratio [HR], 0.52; 95% CI, 0.42-0.65; P < .001). The 12-month PFS rate was 44.2% compared with 27.0% for placebo.