AstraZeneca has announced positive results from a Phase III trial evaluating its PD-L1 inhibitor Imfinzi (durvalumab) and tremelimumab in patients with metastatic non-small cell lung cancer (NSCLC).

In the trial, patients receiving a short course of five cycles of anti-CTLA4 antibody tremelimumab over 16 weeks in addition to Imfinzi and chemotherapy demonstrated a 23% reduction in the risk of death compared to a range of chemotherapy options.

The median overall survival (OS) was 14.0 months versus 11.7 months for chemotherapy, with an estimated 33% of patients receiving the combo alive at two years versus 22% for chemotherapy.

AZ’s combo treatment also reduced the risk of disease progression or death by 28% compared to chemotherapy alone, with a median progression-free survival (PFS) of 6.2 months versus 6.2 months, respectively.

“The POSEIDON data offer patients further benefit from Imfinzi and are an important validation of our development strategy to explore novel combinations. Adding a short course of tremelimumab to Imfinzi for those patients already receiving chemotherapy, reduced the risk of cancer progressing or death by 28% compared to chemotherapy alone,” said Susan Galbraith, executive vice president, Oncology R&D, AZ.

“The results also showed the significant survival improvement did not compromise tolerability in the first-line treatment of patients with metastatic non-small cell lung cancer. We look forward to discussing these data with regulatory authorities,” she added.