FDA Approves First Niemann-Pick Type C Drug, Miplyffa

The US Food and Drug Administration (FDA) has greenlighted Zevra Therapeutics’ Miplyffa (arimoclomol) for the treatment of Niemann-Pick disease type C (NPC), a highly rare lysosomal storage disorder that affects approximately one in every 100,000 to 120,000 births. This approval marks a significant milestone as Miplyffa becomes the first drug approved by the FDA specifically for NPC. The drug, when used in combination with the enzyme inhibitor miglustat, is intended to address the neurological symptoms in both adults and children aged two years and older.

NPC is a genetic disorder stemming from mutations in the NPC1 or NPC2 genes, resulting in an impaired ability to metabolize lipids. This disruption causes progressive losses in patient independence due to both physical and cognitive limitations. Key neurological challenges include impairments in speech, cognition, swallowing, movement, and fine motor skills. Currently, it is estimated that about 900 individuals in the US are living with NPC.

Arimoclomol, the active ingredient in Miplyffa, is taken orally and works by boosting the production and activation of molecular chaperone proteins. These proteins help to break down accumulating lipids more effectively, thereby addressing the root issues caused by NPC.

The FDA’s approval came on the heels of a recommendation from its Genetic Metabolic Diseases Advisory Committee. The decision was driven by comprehensive data, notably from a year-long clinical trial involving NPC patients between the ages of two and 19. The trial demonstrated that the combination of Miplyffa and miglustat halted the progression of the disease over the 12-month treatment period. Specifically, patients on the combination therapy showed a reduction of 0.2 points from baseline on the 4-domain NPC Clinical Severity Scale, in stark contrast to the 1.9 points of progression observed in patients treated with miglustat alone.

Janet Maynard, director of the Office of Rare Diseases, Pediatrics, Urologic and Reproductive Medicine in the FDA’s Center for Drug Evaluation and Research, commented on the significance of this development. She highlighted the severe impact NPC has on patients and their families and noted the urgent need for approved treatments. Maynard affirmed that the approval of Miplyffa is a critical step in meeting the unmet medical needs of those suffering from NPC.

Neil McFarlane, Zevra’s president and chief executive officer, hailed the approval as a "monumental milestone" for NPC patients and their families in the United States. In addition to the drug’s approval, Zevra Therapeutics has been granted a priority review voucher, which will accelerate future FDA reviews of other drug candidates in its pipeline. The company announced that it will immediately commence launch activities for Miplyffa and anticipates that the drug will be commercially available within the next eight to 12 weeks.