Retrophin to Acquire Orphan Technologies

Retrophin has entered into a definitive agreement to acquire Orphan Technologies, a privately held, clinical-stage biopharmaceutical company focused on the development of product candidate OT-58 for the treatment of classical homocystinuria (HCU). OT-58 is a novel investigational enzyme replacement therapy being evaluated in Phase 1/2 development for the treatment of classical HCU, a rare metabolic disorder characterized by elevated levels of plasma homocysteine that can lead to life-threatening thrombotic events such as stroke and heart attacks, ophthalmologic and skeletal complications, as well as developmental delay. Current treatment options, including heavy dietary restrictions and supplemental use of vitamin B6 and betaine, are often ineffective in managing homocysteine levels and a significant unmet need remains.

“Many people with HCU face a continuous risk of developing life-threatening complications because current treatment options are largely ineffective in managing homocysteine levels,” said Eric Dube, Ph.D., chief executive officer of Retrophin. “OT-58 has demonstrated an ability to meaningfully reduce homocysteine levels in preclinical models and has the potential to ultimately become the first disease modifying therapy for HCU. This promising, novel development candidate fits directly with our mission to identify, develop and deliver life-changing therapies to people living with rare disease and brings exciting growth potential to Retrophin.”

OT-58 is a PEGylated, recombinant enzyme replacement therapy designed to address the underlying cause of classical HCU — a deficiency in the naturally occurring enzyme cystathionine beta synthase (CBS). A deficiency in CBS prevents regular metabolism from occurring and results in elevated levels of homocysteine. In preclinical studies, OT-58 has demonstrated an ability to reduce total homocysteine levels and improve clinical parameters. Specifically, dosing of OT-58 in mouse models corrected metabolite levels, including up to 90% reduction in homocysteine levels in plasma and tissues, and appeared to prolong survival, prevent osteoporosis and rescue ocular structure. OT-58 is currently advancing in a Phase 1/2 dose escalation study to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and clinical effects in patients with classical HCU. OT-58 has been granted Rare Pediatric Disease and Fast Track designations by the US Food and Drug Administration (FDA), as well as Orphan Drug designation in the US and Europe.

“Orphan Technologies’ longstanding mission has been to reduce the disease burden for people living with HCU, including debilitating complications of the skeletal, cardiovascular, ocular, and central nervous systems. Therefore, I am extremely proud of the Orphan Technologies team for advancing OT-58 from early stage research and preclinical studies into a Phase 1/2 trial,” said Frank Glavin, chief executive officer of Orphan Technologies. “We are now at an ideal juncture to pair the therapeutic promise of OT-58 with Retrophin’s late-stage development and commercial capabilities in rare diseases. I believe that with this new stewardship, we increase the potential for OT-58 to become an impactful new treatment option for patients.”

Under the terms of the agreement, Retrophin will make an upfront payment of $90 million in cash upon closing of the transaction. Orphan Technologies shareholders will also be eligible to receive up to $427 million in additional cash payments contingent upon the achievement of key milestones in the development and commercialization of OT-58. Retrophin will also pay a tiered mid-single digit royalty on future net sales of OT-58 in the US and Europe, and potentially make a milestone payment in the event a pediatric rare disease voucher is granted.

The transaction has been approved by the boards of directors of both companies. It is subject to customary closing conditions, including consummation of a spinout agreement for Orphan Technologies’ preclinical OT-15 product candidate, and is anticipated to close in the fourth quarter of 2020.