Alexion and Stealth Announce Agreement for develop and Commercialize Late Stage Therapy for Mitochondrial Diseases

Alexion Pharmaceuticals, Inc. and Stealth BioTherapeutics Corp announced an agreement for an option to co-develop and commercialize elamipretide for mitochondrial diseases. Currently being evaluated in a Phase 3 study in people with primary mitochondrial myopathy (PMM) – a genetic mitochondrial disease – elamipretide is a novel, potential first-in-class therapy that targets mitochondrial dysfunction. There are currently no therapies approved to treat PMM, which is characterized by debilitating skeletal muscle weakness, chronic fatigue and exercise intolerance. Under the terms of the agreement, Alexion will have the opportunity to exercise the option following the delivery of results from the Phase 3 study currently underway in PMM.

“Mitochondria play a critical role in normal organ function and, when dysfunctional, can have devastating consequences on multiple organ systems, leading to many serious diseases, such as primary mitochondrial myopathy,” said John Orloff, M.D., Executive Vice President and Head of Research & Development at Alexion. “Given our strong existing relationships with neuromuscular specialists – who play a critical role in treating PMM – we believe this is an exciting potential opportunity to further expand our rare neurology portfolio and look forward to the possibility of working with Stealth to realize the promise of elamipretide for patients.”

“Our mission is to deliver therapies to patients suffering from devastating mitochondrial diseases, and this partnership will enhance our ability to rapidly deliver on that mission,” said Stealth Chief Executive Officer Reenie McCarthy. “Together with Alexion, which is widely recognized for its demonstrated ability to bring important new therapies for rare diseases to children and adults in need, we believe we can achieve synergies of execution that will both expedite and increase patient access following achievement of key upcoming clinical and regulatory milestones for our PMM and Barth syndrome programs.”

Under the terms of the agreement, Alexion will receive an exclusive option to partner with Stealth in the development of subcutaneous elamipretide based on final results from the Phase 3 study currently underway in PMM. If Alexion chooses to exercise the option, the companies will co-develop subcutaneous elamipretide in the U.S. for PMM and Barth syndrome, as well as Leber’s hereditary optic neuropathy (LHON), which is currently in earlier stage clinical development. Upon commercialization, the agreement would provide for a 50-50 co-promote between the two companies in the U.S. and Alexion would receive exclusive rights to develop and commercialize subcutaneous elamipretide outside the U.S. Alexion will make initial payments to Stealth totaling $30 million, including an option fee, an equity investment and development funding. If the option is exercised, the agreement provides for additional payments, including an option exercise fee, an additional equity investment, development funding and potential regulatory and commercial milestone payments. Stealth’s other pipeline assets, including SBT-272, are not included in the option.