Nulibry™ (fosdenopterin; Origin Biosciences) for injection is now available to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A.

MoCD Type A is a rare, inborn error of metabolism caused by mutations in the MOCS1 gene that results in toxic sulfite accumulation in the brain. The disorder typically appears shortly after birth and leads to intractable seizures, brain injury and death. Nulibry replaces missing cyclic pyranopterin monophosphate, which is needed to reduce levels of neurotoxic sulfites.

The approval was based on findings from 3 clinical studies that were compared to data from a natural history study in patients with MoCD Type A. Findings from a combined analysis showed that treatment with Nulibry was associated with a reduced risk of death and a greater 3-year survival rate when compared with untreated, genotype-matched patients in the natural history control.

With regard to safety, the most common adverse reactions reported (incidence of greater than or equal to 25%) with Nulibry were catheter-related complications, pyrexia, viral infection, pneumonia, otitis media, vomiting, cough/sneezing, viral upper respiratory infection, gastroenteritis, bacteremia, and diarrhea. Additionally, Nulibry has been identified through animal studies as having phototoxic potential.

Nulibry is exclusively available through Biologics at McKesson as a single-dose vial containing 9.5mg of fosdenopterin (equivalent to 12.5mg fosdenopterin hydrobromide as a dihydrate) as a lyophilized powder or cake for reconstitution for intravenous infusion. A patient assistance program called ForgingBridges has also been made available to support patients receiving Nulibry.


Nulibry (fosdenopterin), first and only FDA-Approved therapy to reduce the risk of mortality in patients with molybdenum cofactor deficiency Type A, available exclusively at Biologics by McKesson. [press release]. Cary, NC: Biologics by McKesson; April 19, 2021.