AstraZeneca announced that its Imfinzi (durvalumab) and tremelimumab have demonstrated positive progression-free survival (PFS) results in the Phase III POSEIDON trial.

The POSEIDON trial is a randomised, open-label, multi-centre, global, Phase III study of platinum-based chemotherapy Imfinzi, tremelimumab and chemotherapy compared with chemotherapy alone for the treatment of previously-untreated patients with metastatic non-small cell lung cancer (NSCLC).

AstraZeneca oncology R&D executive vice president José Baselga said: “The POSEIDON trial provides evidence of the efficacy of Imfinzi in patients with Stage IV non-small cell lung cancer. Clinical benefit was observed in a trial population that included a high proportion of patients with squamous disease and multiple choices of chemotherapy regimens.

“Additionally, the potential to add tremelimumab to Imfinzi and chemotherapy may present an important treatment approach in this challenging setting, especially taking into consideration the favourable safety profile.”

The triple combination therapy also showed a statistically and clinically significant PFS improvement

Imfinzi is a human monoclonal antibody that binds to PD-L1 to block the interaction of PD-L1 with PD-1 and CD80 and prevents the immune-evading and inhibition of immune responses by the tumour.

Tremelimumab is an anti-CTLA4 human monoclonal antibody that blocks the activity of CTLA-4, to activate the T cells and boost the immune response to cancer.

Lung cancer contributes to approximately one-fifth of all cancer deaths and is classified into NSCLC and SCLC, and patients with NSCLC are further classified into squamous and non-squamous types.

The UK-based pharmaceutical firm reported that the trial has reached a primary endpoint of statistically significant and clinically meaningful improvement in the final PFS analysis.

The combination of Imfinzi, tremelimumab and chemotherapy also showed a statistically and clinically significant PFS improvement compared to the chemotherapy alone as a key secondary endpoint.

Furthermore, Imfinzi has showed consistent safety and tolerability with its known safety profile in the study, and the triple combination therapy did not result in increased discontinuation of therapy.