Health Canada has approved AstraZeneca's (NYSE: AZN) (LSE: AZN) Imfinzi (durvalumab) for the treatment of patients with locally advanced, unresectable non-small cell lung cancer (NSCLC) whose disease has not progressed following platinum-based chemoradiation therapy (CRT), the company's Canadian unit said on Tuesday.

With this approval, Imfinzi is the first and only approved immuno-oncology therapy following CRT for patients in this setting.

Health Canada's decision was based on data from the phase III PACIFIC trial which demonstrated that Imfinzi extended progression-free survival for patients by nearly one year (11.2 months) versus placebo. This represents a 48% reduction in relative risk of progression or death versus placebo in all patients, regardless of programmed death-ligand 1 (PD-L1) status.

Around 35% of all new NSCLC diagnoses are stage III, and approximately 80% of these patients are unsuitable for surgery.