A combination of AstraZeneca's Imfinzi (durvalumab), tremelimumab and chemotherapy has extended overall survival (OS) when used as a first-line treatment for metastatic non-small cell lung cancer (NSCLC).

A final analysis of data from the POSEIDON study shows that the combination demonstrated a statistically significant and clinically meaningful OS benefit versus chemotherapy alone.

The trial also tested a combination of Imfinzi plus chemotherapy which, while showing a statistically significant improvement in progression-free survival (PFS) versus chemotherapy, failed to significantly improve OS.

Each combination demonstrated an acceptable safety profile, and no new safety signals were identified, AZ noted.

“We are pleased to see the POSEIDON Phase III trial demonstrate, for the first time, a significant and clinically meaningful overall survival benefit for Imfinzi plus tremelimumab with chemotherapy in metastatic non-small cell lung cancer,” said Dave Fredrickson, executive vice president, Oncology Business Unit, at AZ.

“We were particularly pleased by the safety profile. We’ve seen encouraging uptake of novel combinations in this setting and believe this new approach will add a further option for patients with high unmet medical need. We look forward to discussing next steps with regulatory authorities.”

The data will be presented at a forthcoming medical meeting, the drugmaker noted.

Imfinzi is a human monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, countering the tumour's immune-evading tactics and releasing the inhibition of immune responses.

Tremelimumab is a human monoclonal antibody and potential new medicine that targets and blocks the activity of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), contributing to T-cell activation, and priming the immune response to cancer and fostering cancer cell death.

The combination of Imfinzi and tremelimumab is currently being tested in lung cancer, bladder cancer and liver cancer settings.