The experimental medicine is a so-called PD-L1 therapy that fights cancer by boosting the immune system.
Breakthrough therapy designation expedites the development and review of medicines intended to treat serious or life-threatening diseases.
Durvalumab is also being developed as a treatment for lung, head and neck, gastric, pancreatic, liver and blood cancers. It faces competition from rival products made by Bristol-Myers Squibb, Merck and Roche.
(Reporting by Ben Hirschler; Editing by Mark Potter)
Source: Reuters Health