AstraZeneca said that the concurrent administration of Imfinzi (durvalumab) with chemoradiotherapy (CRT) has missed the primary endpoint in the PACIFIC-2 Phase 3 trial of patients with unresectable, Stage 3 non-small cell lung cancer (NSCLC).

The combination failed to improve progression-free survival (PFS) against CRT alone in NSCLC patients.

An initial study of the safety and tolerability of Imfinzi and CRT in this patient population revealed that the profiles were generally consistent with the known profiles of these treatments.

The late-stage study noticed an enhanced rate of infection during the concurrent treatment period in the experimental arm.

Based on the outcomes of the PACIFIC Phase 3 trial, Imfinzi sequentially administered after platinum-based CRT has been recognised as the global standard of care for the treatment of unresectable, Stage 3 NSCLC.

Concurrent Imfinzi administration with CRT is being evaluated in the PACIFIC-2 trial to treat patients who advance or stop treatment during CRT and are not eligible for the PACIFIC regimen.

AstraZeneca Oncology R&D executive vice president Susan Galbraith 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.”

The pharmaceutical firm is evaluating Imfinzi in the early stages of lung cancer in several ongoing registrational trials.

In a separate development, Imfinzi in combination with chemotherapy (gemcitabine and cisplatin) has been approved in China as the first line of treatment for adult patients with locally advanced or metastatic biliary tract cancer (BTC).

The approval by China’s National Medical Products Administration (NMPA) was backed by the results from the TOPAZ-1 Phase 3 trial along with a prespecified exploratory analysis of an additional cohort of Chinese patients.

In the trial, Imfinzi plus chemotherapy lowered the death risk by 20% versus chemotherapy alone.