The U.S. Food and Drug Administration (FDA) approved Nulibry (fosdenopterin) for injection to reduce the risk of death due to Molybdenum Cofactor Deficiency Type A, a rare, genetic, metabolic disorder that typically presents in the first few days of life, causing intractable seizures, brain injury and death.

“Today’s action marks the first FDA approval for a therapy to treat this devastating disease,” said Hylton V. Joffe, M.D., M.M.Sc, director of the Office of Rare Diseases, Pediatrics, Urologic and Reproductive Medicine in the FDA’s Center for Drug Evaluation and Research. “The FDA remains committed to facilitating the development and approval of safe and effective therapies for patients affected by rare diseases—an area of critical need.”

Patients with Molybdenum Cofactor Deficiency Type A experience severe and rapidly progressive neurologic damage including intractable seizures, feeding difficulties and muscle weakness from the accumulation of toxic sulfite metabolites in the central nervous system. Most patients die in early childhood from infections. Before today’s approval, the only treatment options included supportive care and therapies directed towards the complications arising from the disease.

Patients with Molybdenum Cofactor Deficiency Type A cannot produce a substance known as cyclic pyranopterin monophosphate (cPMP). Nulibry is an intravenous medication that replaces the missing cPMP. The effectiveness of Nulibry for the treatment of Molybdenum Cofactor Deficiency Type A was demonstrated in 13 treated patients compared to 18 matched, untreated patients. The patients treated with Nulibry had a survival rate of 84% at three years, compared to 55% for the untreated patients.

The most common side effects included complications related to the intravenous line, fever, respiratory infections, vomiting, gastroenteritis and diarrhea.

Phototoxicity (injury to the skin and eyes from certain types of light, such as sunlight) was seen in animals, so patients treated with Nulibry should avoid exposure to sunlight and wear sunscreen, protective clothing, and sunglasses when exposed to the sun.

The FDA granted this application Priority Review and Breakthrough Therapy designations. Nulibry also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases. The sponsor is also receiving a Rare Pediatric Disease Priority Review Voucher under a program intended to encourage development of new drugs and biologics for the prevention and treatment of rare pediatric diseases. A voucher can be redeemed by a sponsor at a later date to receive Priority Review of a subsequent marketing application for a different product.

The FDA granted the approval of Nulibry to Origin Biosciences, Inc.