FDA Approves Zevra’s NPC Therapy

Rare Daily Staff

The U.S. Food and Drug Administration approved Zevra Therapeutics Miplyffa, an oral therapy for the treatment of the ultra-rare lysosomal storage disorder Niemann-Pick disease type C.

It is the first drug for NPC approved by the FDA. The FDA approved the use of Miplyffa for use in combination with miglustat for the treatment of neurological manifestations of NPC in adult and pediatric patients 2 years of age and older.

Zevra said it has received a rare pediatric disease priority review voucher in conjunction with the approval. The voucher entitles the holder to reduce the review time of a new drug application to six months from the standard 10 months. They are potentially lucrative because they are transferrable and have routinely been sold for around $100 million each.

“NPC is an ultra-rare, relentlessly progressive, degenerative, and fatal disease for which there were no FDA-approved treatment options until today,” said Neil McFarlane, president and CEO of Zevra. “The approval of Miplyffa is a monumental milestone for NPC patients and their family members in the U.S.”

An estimated 900 people in the United States are living with NPC. Approximately one-third of them have been diagnosed with the progressive and fatal neurodegenerative disease. Both children and adults can be affected by NPC with varying clinical presentations. Typically, people living with NPC experience progressive physical and cognitive limitations, with key neurological impairments presenting in speech, cognition, swallowing, ambulation, and fine motor skills.

“Until now, those living with NPC have had no FDA-approved treatment to combat this devastating disease,” said Laurie Turner, Family Services Manager, National Niemann-Pick Disease Foundation. “For more than 30 years, NNPDF and the community have been working to find treatments for NPC, and we are grateful for the diligence and commitment of the researchers, clinicians, families and Zevra for making this approval possible.”

The approval of Miplyffa for the treatment of NPC is based on the totality of the data in the New Drug Application, which included additional evidence supporting trial endpoints, FDA-preferred analyses, and additional confirmatory evidence, both clinical and nonclinical.

The safety and effectiveness of Miplyffa were studied in a 12-month multicenter, randomized, double-blind, placebo-controlled trial in patients with NPC between 2 and 19 years of age. In this trial, 76 percent of patients in the Miplyffa group and 81 percent of those in the placebo group received miglustat as part of their routine care. The effectiveness of Miplyffa was evaluated using the rescored 4-domain NPC Clinical Severity Scale (R4DNPCCSS). Results from this trial demonstrated:

Miplyffa, in combination with miglustat, halted disease progression through 12 months of treatment, as demonstrated by a decrease of 0.2 points from baseline on the R4DNPCCSS compared to 1.9 points of progression for patients treated with miglustat alone.

Additional confirmatory evidence included data from a 48-month open-label extension phase of the study, which suggested improved outcomes when compared to a matched National Institutes of Health NPC natural history cohort.

Zevra said it will immediately initiate its launch activities for Miplyffa, which is expected to be commercially available in the United States in eight to 12 weeks.