Cyprium to Sell PRV for $205 Million

Rare Daily Staff

Cyprium Therapeutics, a majority-owned subsidiary of Fortress Biotech, agreed to sell its Rare Pediatric Disease Priority Review Voucher for $205 million.

The voucher was granted to Cyprium after the U.S. Food and Drug Administration in January approved Zycubo, a therapy for Menkes disease licensed to Sentynl Therapeutics in 2023. Under the companies’ earlier agreement, Sentynl assumed full responsibility for developing and commercializing Zycubo, while Cyprium remained eligible for tiered royalties and up to $129 million in milestone payments.

Cyprium will pay 20 percent of the proceeds from the PRV sale to the Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the National Institutes of Health, which collaborated on Zycubo’s development. The sale remains subject to customary closing conditions.

Menkes disease is a rare X-linked recessive pediatric disorder caused by mutations of the copper transporter gene ATP7A, affecting about one in 100,000 newborns per year. Patients have low levels of copper in the blood and brain, as well as abnormal levels of certain neurochemicals. They typically have sparse, kinky hair; connective tissue problems; and severe neurological symptoms such as seizures, hypotonia, and failure to thrive. Mortality is high, with many patients dying before age 3 if untreated.

Zycubo supplements blood and brain copper levels in patients diagnosed with classic Menkes disease who have not demonstrated significant clinical progression. It is a subcutaneous injectable formulation of copper histidinate intended to improve tolerability due to its physiological pH and to bypass oral absorption of copper, which is impaired in Menkes disease.

The Priority Review Voucher program incentivizes pharmaceutical companies to develop treatments for rare pediatric diseases. Before a treatment is approved, a company can obtain a rare pediatric disease designation from the FDA. To be eligible, the drug must qualify for priority review and represent the first approval for its active ingredient.

After the FDA approves an eligible treatment, the company receives a PRV that can be used to obtain priority review for another therapy that would not otherwise qualify. Priority review means the FDA generally completes its review within six months rather than the standard 10 months. The vouchers are potentially lucrative because they are transferable.

“The sale of the PRV shows our continued execution in value-generating transactions,” said Lindsay Rosenwald, chairman, president, and CEO of Fortress, and chairman of Cyprium. “With three FDA approvals in the last 15 months and the recent sale of Checkpoint Therapeutics to Sun Pharma, we believe we are well positioned to reach profitability this year.”