The Phase III PACIFIC trial has made significant progress on the treatment of locally advanced non-small cell lung cancer (NSCLC) when both the progression-free survival (PFS) and overall survival (OS) results were announced separately. 3 years later with updated results, the PACIFIC trial continues to evidence improvement in outcomes with the use of durvalumab (imfinzi) in patients with unresectable, stage III NSCLC who do not progress on chemotherapy.
Lead Study Author: Jhanelle Gray: Improvements!
Dr. Gray reports that “For unresectable stage III NSCLC, previously, the 5-year survival rates were about 15% to 30%. The PACIFIC trial has changed the standard-of-care treatment for our patients by moving immunotherapy into the consolidation setting following completion of concurrent chemotherapy and radiation therapy.” Dr. Gray recently presented the findings at the 2019 ASCO Annual Meeting in an interview with Targeted Oncology.
The randomized, double-blinded, international, Phase III PACIFIC trial has enrolled 713 patients with stage III locally advanced, unresectable NSCLC who had not progressed after at least 2 cycles of concurrent platinum-based chemoradiotherapy. The patients were randomized 2:1 to receive either durvalumab (n = 476) or placebo (n = 237) as consolidation treatment. The primary trial endpoints included PFS and OS.
57% of patients receiving durvalumab were still alive compared with 43.%% of patients in the placebo arm. 50% of the patients are still alive at 3 years and this represents a key takeaway to Dr. Gray. She notes “we have not seen results like this in the past and I think it represents a significant milestone in unresectable stage III lung cancer.”
A significant difference in the PFS was noted between the 2 study arms, with 16.8 months seen in the durvalumab arm compared with 5.6 months in the placebo arm.
Durvalumab (trade name Imfinzi) is FDA-approved immunotherapy for cancer, developed by Medimmune/AstraZeneca. It is a human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody that blocks the interaction of programmed cell death ligand 1 (PD-L1) with the PD-1 and CD80 (B7.1) molecules. Durvalumab is approved for the treatment of patients with locally advanced or metastatic urothelial carcinoma who either have disease progression during or following platinum-containing chemotherapy or have disease progression within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy.
Durvalumab is known as a checkpoint inhibitor drug. The list price for the drug from AstraZeneca is $180,000 for a year.
Jhanelle Gray, MD, director of clinical research in the Department of Thoracic Oncology at H. Lee Moffitt Cancer Center and Research Institute, Tampa FL