AstraZeneca provides update on the Phase III MYSTIC trial of Imfinzi and tremelimumab in Stage IV NSCLC.

AstraZeneca and MedImmune, its global biologics research and development arm, announced final overall survival (OS) results for the Phase III MYSTIC trial, a randomised, open-label, multi-centre, global trial of Imfinzi (durvalumab) monotherapy and the combination of Imfinzi and tremelimumab, an anti-CTLA4 antibody, versus standard-of-care (SoC) platinum-based chemotherapy in previously-untreated patients with Stage IV (metastatic) non-small cell lung cancer (NSCLC).

In the primary analysis population of patients, whose tumours express PD-L1 on 25% or more of their cancer cells as determined by the VENTANA PD-L1 (SP263) Assay, Imfinzi monotherapy and the combination of Imfinzi plus tremelimumab did not meet the primary endpoints of improving OS compared to SoC chemotherapy. While the OS result did not meet statistical significance, a hazard ratio (HR) of 0.76 (97.54% CI 0.564-1.019; nominal p=0.036) was observed with Imfinzi monotherapy. The combination therapy had an HR of 0.85 (98.77% CI 0.611-1.173; nominal p=0.202); the data support further analysis in exploratory subgroups. The safety and tolerability profiles for Imfinzi and the Imfinzi plus tremelimumab combination were consistent with previous trials.