Phase III NEPTUNE trial of Imfinzi with tremelimumab for Stage IV NSCLC did not meet the primary endpoint

AstraZeneca announced final overall survival (OS) results from the Phase III NEPTUNE trial , a randomised, open-label, multi-centre, global trial of Imfinzi (durvalumab) in combination with tremelimumab, an anti-CTLA4 antibody, vs. standard-of-care (SoC) platinum-based chemotherapy in previously-untreated Stage IV (metastatic) non-small cell lung cancer (NSCLC) patients. The trial was performed in an all-comers population, and the primary analysis population was patients with a high tumour mutational burden (TMB). TMB is a measurement of the number of mutations within the genome (DNA) of a tumour, and tumours with high levels of TMB may be more visible to the immune system.

In the primary analysis population of patients whose blood TMB was 20 or more mutations per megabase (mut/Mb), the combination of Imfinzi and tremelimumab did not meet the primary endpoint of improving OS compared to SoC chemotherapy . The safety and tolerability profile for the combination of Imfinzi and tremelimumab was consistent with previous trials. AstraZeneca will submit the full results for presentation at a forthcoming medical meeting.

Imfinzi is also being tested as monotherapy in the Phase III PEARL trial, and in combination with chemotherapy with or without tremelimumab in the Phase III POSEIDON trial as part of an extensive late-stage Immuno-Oncology programme in Stage IV NSCLC.