Phase III MYSTIC trial of Imfinzi (durvalumab) monotherapy or Imfinzi + tremelimumab not meet the primary endpoint for Stage IV NSCLC.-AstraZeneca + Medimmune

AstraZeneca and MedImmune, have announced progression-free survival (PFS) results for the Phase III MYSTIC trial, a randomised, open-label, multi-centre, global trial of Imfinzi (durvalumab) monotherapy or Imfinzi in combination with tremelimumab versus platinum-based standard-of-care (SoC) chemotherapy in previously-untreated patients with metastatic (Stage IV) 1st-line non-small cell lung cancer (NSCLC). The combination of Imfinzi and tremelimumab did not meet the primary endpoint of improving PFS compared to SoC in patients whose tumours express PD-L1 on 25% or more of their cancer cells (as determined by the VENTANA PD-L1 (SP263) assay). As a secondary endpoint, although not formally tested, Imfinzi monotherapy would not have met a pre-specified threshold of PFS benefit over SoC in this disease setting. The trial will continue to assess two additional primary endpoints of overall survival (OS) for Imfinzi monotherapy and OS for the Imfinzi plus tremelimumab combination. Final OS data from both primary endpoints are expected during the first half of 2018.