Shire has bagged the rights outside North America to Acceleron Pharma's investigational duchenne muscular dystrophy drug in a deal that could be worth around $500 million.

The agreement covers Acceleron's activin receptor type IIB class of molecules, the lead candidate being ACE-031 for DMD, which is in a Phase IIa trial. DMD is a fatal orphan muscle disease with no current treatment.

Cashwise, Shire will pay an upfront fee of $45 million and Acceleron is also eligible to receive additional milestones of up to $165 million for the successful commercialisation of ACE-031 in DMD. The privately-held firm based in Cambridge, Massachusetts could receive an additional $288 million related to other indications and molecules, as well as royalties.

Sylvie Gregoire, president of Shire Human Genetic Therapies, said the collaboration is "an excellent strategic fit to the work that [the company] is already doing on behalf of patients with rare diseases". She added that working with Acceleron "allows us to use our expertise to help patients suffering from this devastating disease, as well as expand our pipeline into a new therapeutic area".