Update on PACIFIC-2 phase III trial of Imfinzi concurrently administered with platinum-based chemoradiotherapy in unresectable, Stage III non-small cell lung cancer

Imfinzi sequentially administered after platinum-based CRT is the established, global standard of care for the treatment of unresectable, Stage III NSCLC based on the results of the PACIFIC Phase III trial. The PACIFIC-2 trial was initiated to evaluate concurrent Imfinzi administration with CRT, with the aim of addressing patients who progress or discontinue treatment during CRT and are therefore ineligible for the PACIFIC regimen.

Initial analysis of the safety and tolerability for Imfinzi and CRT in this patient population showed that the profiles were broadly consistent with the known profiles of these treatments, although there was an increased rate of infection observed during the concurrent treatment period in the experimental arm.

Jeffrey D. Bradley, MD, Vice Chair of Proton Therapy & Technology Development, Penn Medicine, Philadelphia and principal investigator for the trial said: “While the PACIFIC-2 trial results did not show what we hoped, the PACIFIC regimen remains the standard of care for patients with unresectable, Stage III non-small cell lung cancer. As a community, we will take insights from these results to advance future research.”

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “Our goal with the PACIFIC-2 trial was to address a remaining unmet need for patients in this setting by introducing immunotherapy even earlier and concurrently administering Imfinzi with chemoradiotherapy. While today’s results did not reach statistical significance, we will learn from this trial and we remain committed to improving patient outcomes by expanding the benefit of immunotherapy to lung cancer patients across treatment settings.”

PACIFIC-2: The PACIFIC-2 trial was a Phase III, randomised, double-blind, placebo-controlled, multi-centre international study of Imfinzi concurrently administered with platinum-based CRT in patients with unresectable, Stage III NSCLC. In the trial, patients were randomised 2:1 to receive a 1,500mg fixed dose of Imfinzi or placebo every four weeks starting at the beginning of definitive CRT. Patients continued to receive Imfinzi or placebo as consolidation treatment after CRT until disease progression. The trial was conducted at 88 centres across more than 20 countries involving 328 patients. The primary endpoint was PFS, and key secondary endpoints included overall survival, objective response rate and duration of response AstraZeneca has several ongoing registrational trials focused on testing Imfinzi in early stages of lung cancer, including in resectable NSCLC (ADJUVANT BR.31), medically inoperable or unresected Stage I-II NSCLC (PACIFIC-4) and unresectable, Stage III NSCLC (PACIFIC-5, 8 and 9), and in limited-stage small-cell lung cancer (SCLC) (ADRIATIC).