Beren Therapeutics has announced that the US FDA has extended by three months its review of the New Drug Application (NDA) for adrabetadex (2-hydroxypropyl-β-cyclodextrin), pushing the PDUFA target action date to November 17, 2026. Beren is seeking approval for adrabetadex in infantile-onset Niemann-Pick disease, type C (I-NPC), a severe pediatric neurodegenerative disorder with no currently approved treatment in the US.
The FDA drug review extension follows Beren's March 18, 2026 response to an agency information request, which included updates and clarifications to existing data and supporting documentation. The FDA classified that response as a Major Amendment to the NDA — a designation that, under agency regulations, automatically triggers a three-month extension to the review timeline. The NDA had previously been granted Priority Review status, and adrabetadex carries both Orphan Drug and Breakthrough Therapy designations. Beren added that it continues to provide access to adrabetadex for eligible patients through an ongoing Expanded Access Program.
The NDA submission is supported by more than a decade of clinical development, according to Beren. Adrabetadex is formulated as a proprietary mixture of 2-hydroxypropyl-β-cyclodextrin isomers designed for intrathecal delivery, a route chosen to address the drug's limited central nervous system penetration when administered systemically. The company said clinical and nonclinical data demonstrate that adrabetadex directly targets the underlying pathophysiology of NPC by re-establishing intracellular cholesterol trafficking — the core metabolic defect caused by loss-of-function variants in the NPC1 or NPC2 genes. The most commonly observed adverse events in clinical experience include hearing impairment, which the company described as manageable with hearing aids when necessary, and post-dose fatigue and ataxia. Specific trial identifiers and efficacy endpoints underpinning the NDA were not detailed in the announcement.
Infantile-onset Niemann-Pick disease type C treatment remains an area of profound unmet need. I-NPC, defined by neurological symptom onset before age six, is associated with particularly rapid disease progression; mean age of death has been reported at approximately 5.6 years for early infantile onset and 13.4 years for late-infantile onset, according to the company's disclosure.