Alexion Pharmaceuticals will pay Stealth BioTherapeutics $30m (€27.2m) upfront to enter the deal, with further undisclosed milestone payments also agreed.
The asset at the center of the deal, elamipretide, is already going through a Phase III study as a treatment for primary mitochondrial myopathy (PMM). The drug candidate is also in early clinical development for Barth syndrome and Leber’s hereditary optic neuropathy.
The first stage of the partnership will be an assessment of Phase III clinical readouts, at which point Alexion has the option to opt-in to the co-development and commercialization of Stealth’s lead asset. According to Stealth, the results of the study will be available before the end of the year.
Should Alexion exercise the opt-in right, the company will gain 50% rights to elamipretide in the US market and exclusive rights for ex-US territories.
Elamipretide functions by targeting the inner mitochondrial membrane, with previous clinical trials indicating that it is able to increase mitochondrial respiration, improve the electron transport chain function and ATP (adenosine triphosphate) production.
If the treatment receives approval, it would become a first-in-class therapy for PMM, and would be administered subcutaneously.
For Alexion, the asset represents an opportunity to expand its neurology portfolio.
The company has made efforts to expand its portfolio beyond its lead drug Soliris (eculizumab) by acquiring a late stage asset through its $855m acquisition of Wilson Therapeutics.
Furthermore, Alexion recently proceeded with an $1.2bn deal for Syntimmune and its monoclonal antibody for the treatment of autoimmune hemolytic anemia.