December 19, 2025

Letter to the NPC Community: Filing of Adrabetadex New Drug Application with FDA for Infantile NPC

Dear NPC Community Partners,

We are pleased to share that on December 17, 2025, Beren Therapeutics P.B.C.®, through its subsidiary Mandos LLC®, submitted a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA) for adrabetadex. This application seeks approval for the treatment of patients with infantile-onset Niemann-Pick disease type C (NPC).

First of all, thank you. This milestone reflects the dedication and extraordinary commitment of families affected by NPC.

Since acquiring adrabetadex* (VTS-270) in 2021, Mandos has worked closely with the FDA to define the regulatory path supporting this submission, including the design and implementation of an externally-controlled survival analysis. Adrabetadex has received Orphan Drug Designation and was granted Breakthrough Therapy Designation in infantile-onset NPC by the FDA in 2025.

The NDA submission includes comprehensive evidence that considers all data generated from the adrabetadex development program. The primary source of evidence in support of efficacy comes from survival analyses comparing integrated data from infantile-onset patients treated for up to 11 years in clinical studies and the Expanded Access Program (EAP) with matched external controls. The study showed that overall survival was improved in infantile-onset NPC patients treated with adrabetadex. The package is further supported by additional clinical biomarker evidence demonstrating effects on the underlying pathology of NPC, patient experience narratives, and safety data from clinical trials and the EAP.

Data from the clinical trials and EAPs suggest that adrabetadex is well-tolerated. The most common adverse events associated with treatment include hearing impairment (manageable with hearing aids if needed) and transient post-dose fatigue and/or ataxia.

The FDA has a 60-day filing review period to determine whether the NDA is complete and accepted for review. If accepted, we anticipate a regulatory decision regarding the NDA as early as Q3 2026.

During the review period, the adrabetadex EAP will continue and be accessible to all eligible patients.

We will be presenting key findings at WORLDSymposium™  in San Diego this coming February and would be happy to connect in person. In the meantime, please reach out with any questions.

From all of us here at Beren – we are deeply grateful to all members of the NPC community who have shared their time, experience, and sacrifice to help move this program forward. We recognize the daily realities that people living with NPC and their caregivers face, and your partnership has helped guide our work with urgency and careful stewardship at every step.

Wishing you and yours a happy and healthy holiday season,

Cathy Traz
Vice President, Patient & Community Engagement

Beren Therapeutics P.B.C.