Retrophin Agrees to Acquire Orphan Technologies for up to $517 Million

Rare Daily Staff

Retrophin said that it has entered into a definitive agreement to acquire Orphan Technologies, a privately held, clinical-stage biopharmaceutical company focused on the development of OT-58, a treatment of the rare metabolic disorder classical homocystinuria, for up to $517 million.

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 United States and Europe, and potentially make a milestone payment in the event a pediatric rare disease voucher is granted.

Classical homocystinuria (HCU) is 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.

OT-58 is an experimental PEGylated, recombinant enzyme replacement therapy being evaluated in phase 1/2 development for the treatment of HCU. OT-58 is 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 percent 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 U.S. Food and Drug Administration, as well as Orphan Drug designation in the United States and Europe.

“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, CEO 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.”

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.

Photo: Eric Dube, CEO of Retrophin