Medimmune is welcoming biotech firm Amplimmune to the AstraZeneca family in a deal that could be worth up to $500m for the Johns Hopkins University spin-out.

Medimmune, the research and development unit of life sciences conglomerate AstraZeneca, acquired 100% of Amplimmune’s shares for an initial consideration of $225m. A further $275m is available based on the US-based biotech hitting certain development milestones.

Amplimmune, founded in 2007, is developing treatments which bolster the immune system and intended for patients being treated for cancer, autoimmune disease, and transplantation. It has raised $20m in the past from a single series A round held when it was founded, and backed by venture firm InterWest Partners and UK-based research funding charity The Wellcome Trust.

Michael Richman, Amplimmune’s chief executive, said:  “Both companies are passionate about developing new cancer therapies for patients and are excited about the potential of immunotherapies.  We are pleased to be joining MedImmune, who will work to further advance the pioneering work we’ve been conducting in this area. The synergy achieved by combining our pipelines provides an important path towards developing novel immunotherapy products.”