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The FDA is expected to decide on Adrabetadex for Infantile-onset Niemann-Pick disease type C by November 17, 2026, under an NDA from Beren Therapeutics.
What the FDA is deciding on Adrabetadex for Niemann-Pick Disease Type C
The FDA is reviewing Beren Therapeutics' application to approve Adrabetadex for infantile-onset Niemann-Pick disease type C.
The FDA moved the decision from August 17 to November 17, 2026 after classifying Beren's March 18, 2026 response to an information request as a major amendment. Adrabetadex is a cyclodextrin drug given into the spinal fluid. The application has priority review and Breakthrough Therapy and Orphan Drug designations.
Who the Adrabetadex decision matters to
Niemann-Pick Disease Type C (NPC) is a rare, progressive lysosomal lipid storage disorder caused by mutations in the NPC1 or NPC2 genes, which encode proteins critical for cholesterol and lipid trafficking. This leads to accumulation of unesterified cholesterol and other lipids in lysosomes, particularly in the nervous system and liver, causing progressive neurological deterioration and hepatosplenomegaly.
Prevalence: Approximately 1 per 100,000 to 1 per 150,000 live births; higher in certain populations. See our full Niemann-Pick Disease Type C page for current treatments, recruiting trials, and community resources.
How Adrabetadex works
Adrabetadex: a mixture of 2-hydroxypropyl-beta-cyclodextrins that Beren says draws cholesterol out of the lysosomes where it is trapped in NPC cells, restoring cholesterol trafficking. Our full Adrabetadex profile covers how it works, side effects in plain language, and its trial history.
What an approval or a rejection of Adrabetadex would mean
An approval starts a second race rather than ending the first one: specialty pharmacy setup, insurance review, and patient assistance typically take weeks even when everything goes right. Our guide to the 90 days after a rare disease approval explains the timeline and the moves families can make on day 1.
A complete response letter would mean the FDA declined to approve in the application's current form. The letter describes what the FDA wants addressed, and the company then decides whether to resubmit, run more studies or stop. Either way, this page updates with the outcome and what it means.
Where Niemann-Pick Disease Type C treatment stands today
Read our full Niemann-Pick Disease Type C treatment summary
As of October 14, 2026, a child under 2 who weighs less than 15kg falls outside both FDA-approved NPC drugs, Miplyffa (from age 2, with miglustat) and Aqneursa (from 15kg), and every NPC treatment trial recruiting in the federal trials registry starts at age 4, according to Trial Friend's check of the labels and trial records.
The FDA is due to decide by November 17, 2026 on adrabetadex, which Beren Therapeutics is seeking for infantile-onset NPC, meaning neurological symptoms that begin before age 6. Research in Niemann-Pick Type C is advancing through multiple approaches to slow the devastating neurological progression that characterizes this condition.
The FDA has approved 2 drugs for the neurological symptoms of NPC, both in September 2024: Miplyffa (arimoclomol), taken together with miglustat by adults and children 2 years and older, on September 20th, and Aqneursa (levacetylleucine), for adults and children weighing at least 15kg, on September 24th.
Miglustat, an iminosugar that reduces the buildup of certain fats (substrate reduction), is approved for NPC in Europe but has no NPC approval of its own in the U.S. Cyclodextrin drugs, which aim to move trapped cholesterol out of cells, have also been tested in clinical trials; an IV version, Trappsol Cyclo, missed its Phase 3 primary endpoint on September 30, 2026, and Beren Therapeutics' adrabetadex, given into the spinal fluid, is under FDA review for infantile-onset NPC with a decision due by November 17, 2026. Gene therapy and cell-based therapies represent exciting emerging approaches.
Trials measure treatment effects through standardized neurological rating scales, gait assessment, cognitive testing, eye movement abnormalities, and brain imaging, along with biochemical markers reflecting disease burden. Early intervention before or very early in symptom appearance shows the most promise.
Genetic confirmation through NPC1/2 testing helps guide treatment selection.
Family members who have inherited the same mutation benefit from screening and early intervention discussion before symptoms develop. Biomarker monitoring helps track disease progression and treatment response.
The Niemann-Pick Disease Type C page has every treatment and trial →Meanwhile, 6 Niemann-Pick Disease Type C studies are open or about to open
Whatever the FDA decides here, research on Niemann-Pick Disease Type C does not stop. Of these, 4 test a treatment; the others follow patients over time. The most recently updated:
We'll email you when the decision is public, with what it means in plain language, and when new trials open for Niemann-Pick Disease Type C. Unsubscribe anytime.
- Trial Alerts, when a new trial opens or a trial changes
- Disease Updates, FDA decisions and condition news, usually 1 or 2 emails a month
Frequently asked questions
When will the FDA decide on Adrabetadex?
The FDA's target date (PDUFA date) for Adrabetadex in Infantile-onset Niemann-Pick disease type C is November 17, 2026.
Who disclosed it: Beren Therapeutics. The FDA does not publish these dates.
Can it move: the FDA can act early, and a major amendment to the application can push the date back 3 months.
Source: Beren Therapeutics announcement
What is Adrabetadex being reviewed for?
Beren Therapeutics submitted an NDA for Adrabetadex in Infantile-onset Niemann-Pick disease type C.
What to know: The FDA moved the decision from August 17 to November 17, 2026 after classifying Beren's March 18, 2026 response to an information request as a major amendment. Adrabetadex is a cyclodextrin drug given into the spinal fluid. The application has priority review and Breakthrough Therapy and Orphan Drug designations.
How it works: A mixture of 2-hydroxypropyl-beta-cyclodextrins that Beren says draws cholesterol out of the lysosomes where it is trapped in NPC cells, restoring cholesterol trafficking.
More: the Adrabetadex drug page explains it in plain language.
Is there already an FDA-approved treatment for Niemann-Pick Disease Type C?
Yes. Trial Friend's drug list includes 2 FDA-approved drugs for Niemann-Pick Disease Type C.
Approved: Miplyffa (arimoclomol), Aqneursa (levacetylleucine).
Check: the Niemann-Pick Disease Type C page also searches FDA drug labels for approved treatments.
What did the Adrabetadex trials show?
Beren reported in October 2025, and repeated in March 2026, that 72 people with infantile-onset NPC treated with adrabetadex had a 71% lower risk of death than 119 matched untreated people from the NIH natural history study and other databases, with 5-year survival of 84% against 42%. In 79 treated patients, neurological decline was 43% slower in the year after starting than before, Beren reported.
More: the Adrabetadex drug page has the full trial history and sources.
What are the side effects of Adrabetadex?
Beren lists hearing impairment, which it says can be managed with hearing aids, and tiredness or unsteadiness after a dose as the main adverse events. The NIH reported in 2017 that patients in its early study had additional hearing loss that hearing aids compensated for.
More: the Adrabetadex drug page has the safety details reported so far.
Can I get Adrabetadex before the FDA decides?
Usually only through a clinical trial or an expanded access program, and the company decides whether to offer one.
Trials: 6 Niemann-Pick Disease Type C studies are open or about to open, 4 of them testing a treatment. See them.
Check your fit: Match Me compares your details with every open trial.
Expanded access: your doctor can ask Beren Therapeutics directly. Registered programs are listed on ClinicalTrials.gov.
How much will Adrabetadex cost?
Beren Therapeutics has not announced a price. Drugmakers usually set it around approval.
Help paying: drugmaker programs and charity funds usually open at launch.
Find help: the patient assistance finder lists programs by insurance type.
What happens after the Adrabetadex decision?
This page updates with the outcome the day it is announced.
If approved: getting the drug still takes time. Specialty pharmacy setup, insurance review and patient assistance often take weeks. Our guide covers what families can do on day 1.
If not approved: a complete response letter means the FDA declined the application in its current form. Many are about manufacturing or how data were presented, and companies often resubmit.
Where this date comes from
The FDA does not publish PDUFA dates; companies disclose them. This one comes from Beren Therapeutics announcement. Dates can move, and the FDA can act early or late. This page rechecks against our calendar, which is re-verified daily.