Zevra Therapeutics has announced US Food and Drug Administration (FDA) approval for Miplyffa (arimoclomol) to treat Niemann-Pick disease type C (NPC).

The capsules treat adult and paediatric patients aged two years and older and are used in conjunction with miglustat to address neurological symptoms of NPC.

The asset was also granted a rare paediatric disease priority review voucher (PRV).

The latest approval was based on comprehensive data from the new drug application (NDA), which included evidence supporting trial endpoints, FDA-preferred analyses and additional confirmatory clinical and nonclinical evidence.

A 12-month multicentre, randomised, double-blind, placebo-controlled trial involving patients aged two to 19 years demonstrated Miplyffa's safety and effectiveness when used with miglustat.

The combination showed a halt in disease progression over 12 months - a significant finding compared to patients treated with miglustat alone.

A 48-month open-label extension study provided additional confirmatory evidence of improved outcomes when compared to a National Institutes of Health NPC natural history cohort.

Miplyffa is taken orally three times daily, with or without food. The dosage varies from 47mg to 124mg depending on body weight, and should be administered by patients or caregivers under healthcare provider guidance.

The company is set to commence launch activities, with Miplyffa available in the US market within in autumn/winter 2024.

Zevra Therapeutics president and CEO Neil McFarlane stated: “NPC is an ultra-rare, relentlessly progressive, degenerative and fatal disease for which there were no FDA-approved treatment options until today.

“The approval of Miplyffa is a monumental milestone for NPC patients and their family members in the US. We are immensely grateful for the unwavering support we have received over the years from the families and individuals impacted by NPC as well as the collaborative efforts of advocacy groups, researchers and clinicians.”