Sentynl Therapeutics has announced the publication of landmark clinical evidence supporting NULIBRY (fosdenopterin) for the treatment of Molybdenum Cofactor Deficiency (MoCD) Type A, an ultra-rare genetic disorder. The comprehensive data, published in the Journal of Inherited Metabolic Disease, represents the first complete body of clinical research comparing NULIBRY treatment outcomes to the natural progression of the disease.
The clinical studies demonstrated statistically significant survival benefits in treated patients compared to untreated individuals. According to the data, untreated patients faced a risk of death 5.1 times higher than those receiving fosdenopterin (Cox proportional hazards 5.1; 95% CI 1.32-19.36; p=0.01). Beyond survival, the research documented significant improvements in cognitive and motor functioning among treated patients.
Understanding MoCD Type A
MoCD Type A is an autosomal recessive, inborn error of metabolism caused by mutations in the MOCS1 gene. This ultra-rare condition affects approximately 1 in 342,000 to 411,000 live births (0.24 and 0.29 per 100,000) in the United States, though experts believe it may be underdiagnosed.
The disease typically presents at birth or shortly thereafter, with common symptoms including seizures, feeding difficulties, and encephalopathy. Without treatment, MoCD Type A causes rapid, irreversible neurodegeneration due to toxic sulfite buildup in the brain, ultimately leading to premature death.
Professor Guenter Schwarz from the Institute of Biochemistry at Cologne University, Germany, highlighted the significance of this milestone: "This publication marks the end of a truly collaborative and enthusiastic path from basic research to the bedside that started 21 years ago, when we reported the successful treatment of a mouse model of MoCD type A with cPMP (cyclic pyranopterin monophosphate, fosdenopterin)."
Treatment Mechanism and Safety Profile
NULIBRY functions as a substrate replacement therapy, providing a synthetic source of cyclic pyranopterin monophosphate (cPMP), which is converted to molybdopterin and subsequently to molybdenum cofactor. This process activates molybdenum-dependent enzymes, including sulfite oxidase, which reduces levels of neurotoxic sulfites in the brain.
The safety profile from the clinical studies showed that fosdenopterin-treated patients experienced primarily mild to moderate treatment-emergent adverse events. The most common adverse reactions included catheter-related complications (89%), fever (78%), viral infection (56%), and pneumonia (44%). Importantly, no patients discontinued treatment or required dose modifications due to adverse events.
Dr. Liza Squires, Sentynl Medical Consultant, emphasized the importance of early diagnosis: "It is important that clinicians consider the diagnosis of MoCD type A in neonates with intractable seizures, encephalopathy, feeding difficulties or increased startle response as earlier treatment appeared to improve achievement of developmental milestones."
Regulatory Status and Global Availability
Fosdenopterin has received regulatory approval from multiple international health authorities. The U.S. Food and Drug Administration (FDA) granted approval in February 2021, followed by the Israeli Ministry of Health in July 2022, the European Medicines Agency (EMA) in September 2022, and most recently, the UK's Medicines and Healthcare products Regulatory Agency (MHRA) in April 2024.
"The publication of these data in JIMD is a huge milestone for MoCD Type A patients, caregivers, and the medical community," said Matt Heck, CEO of Sentynl. "It is the culmination of four companies' commitment in NULIBRY's clinical development program spanning over two decades."
Important Safety Considerations
Healthcare providers should be aware that NULIBRY can cause photosensitivity in patients. Caregivers are advised to minimize patient exposure to sunlight and artificial UV light, with recommendations to use protective clothing, sunglasses, and broad-spectrum sunscreen for patients 6 months and older.
Future Implications
This publication represents a significant advancement in the treatment of ultra-rare genetic disorders that affect infants and young children. The comprehensive clinical evidence not only validates NULIBRY's efficacy but also provides crucial insights into the natural history of MoCD Type A, potentially improving early diagnosis rates.
Sentynl Therapeutics, a U.S.-based biopharmaceutical company owned by Zydus Lifesciences Ltd., continues to focus on bringing innovative therapies to patients with rare diseases. The company's commitment to addressing unmet needs in the rare disease space aligns with growing industry efforts to develop treatments for conditions that affect small patient populations but have devastating consequences if left untreated.
