Positive progression-free survival results for Imfinzi and tremelimumab when added to chemotherapy, from the phase III POSEIDON trial in previously-untreated stage IV (metastatic) NSCLC.- AstraZeneca.

AstraZeneca announced positive progression-free survival (PFS) results for Imfinzi (durvalumab) and tremelimumab, an anti-CTLA4 antibody, when added to chemotherapy, from the Phase III POSEIDON trial in previously-untreated Stage IV (metastatic) non-small cell lung cancer (NSCLC). The trial met a primary endpoint by showing a statistically significant and clinically meaningful improvement in the final PFS analysis in patients treated with the combination of Imfinzi and a broad choice of five standard-of-care platinum-based chemotherapy options vs. chemotherapy alone.

The triple combination of Imfinzi plus tremelimumab and chemotherapy also demonstrated a statistically significant and clinically meaningful PFS improvement vs. chemotherapy alone as a key secondary endpoint. The safety and tolerability of Imfinzi was consistent with its known safety profile. The triple combination delivered a broadly similar safety profile to the Imfinzi and chemotherapy combination and did not result in increased discontinuation of therapy. 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 POSEIDON trial will continue to assess the additional primary endpoint of overall survival (OS) with data anticipated in 2020. AstraZeneca will submit the results for presentation at a forthcoming medical meeting and plans to share the results with health authorities Imfinzi is also being tested in Stage IV NSCLC as monotherapy in the Phase III PEARL trial, and in earlier stages of disease as part of an extensive Immuno-Oncology programme in lung cancer.

Imfinzi is approved in the curative-intent setting of unresectable, Stage III NSCLC after chemoradiation therapy in 53 countries, including the US, Japan and across the EU, based on the Phase III PACIFIC trial.