AstraZeneca Plc (LON:AZN) and MedImmune, its global biologics research and development arm, announced today 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.
Sean Bohen, Executive Vice President of AstraZeneca, Global Medicines Development and Chief Medical Officer, said: “We are encouraged to see that Imfinzi monotherapy activity is in-line with that of the anti-PD-1 class in previously-untreated patients with Stage IV non-small cell lung cancer; however, we are disappointed that these results missed statistical significance. We remain confident in Imfinzi as the cornerstone of our IO programme and continue to evaluate its potential in ongoing non-small cell lung cancer trials, including Imfinzi and Imfinzi plus tremelimumab in combination with chemotherapy.”
Imfinzi is approved for unresectable, Stage III NSCLC in more than 40 countries, including the US, EU and Japan, based on the Phase III PACIFIC trial. Imfinzi is currently being tested in a range of Phase III trials for Stage IV NSCLC.