PDUFA Date

FDA priority review sets Sept. 19 decision on AQNEURSA for A-T

IntraBio's supplemental filing seeks the first approved therapy for ataxia-telangiectasia, built on a 17-patient trial that later terminated after results posted.

By AppliedXLJuly 13, 2026Trial NCT03759678

Executive Summary

The FDA is set to rule on whether to extend an already-approved drug's label into a neurodegenerative disease that currently has no approved treatment.
The regulatory case rests on the drug's existing approved safety record for a different disease, paired with a compact ataxia-telangiectasia trial that closed out with a terminated status after its results were posted.
No competing therapy has reached approval in this disease, and the sponsor's own registrational study is the only late-stage program targeting it directly.
A clearance would establish the first approved medicine for this disease and validate a small-trial regulatory path other rare-disease programs could look to test.

The filing

IntraBio Inc. said the FDA accepted its supplemental NDA for AQNEURSA and granted Priority Review, with a PDUFA target action date of September 19, 2026. The company simultaneously submitted a variation application to the European Medicines Agency to expand AQNEURSA's marketing authorization to cover ataxia-telangiectasia, which it described as the first regulatory application submitted to the EMA seeking approval of a therapy for the disease. Ataxia-telangiectasia is a rare, inherited neurodegenerative disorder that begins in early childhood, causing progressive loss of coordination, impaired speech, and immune deficiency, and it has no approved therapies today. IntraBio

The existing approval base

AQNEURSA already carries approval in the United States for neurological manifestations of Niemann-Pick disease type C in patients weighing at least 15 kg, and in the European Economic Area for the same indication in patients aged 6 and older weighing at least 20 kg. Because the molecule is already on the market for a different neurodegenerative condition, the regulatory question for ataxia-telangiectasia turns less on establishing a new safety profile and more on whether the submitted efficacy data support extending the existing label to a new population. IntraBio

The trial behind the filing

The clinical evidence traces to NCT03759678, a Phase 2 study of N-Acetyl-L-Leucine in ataxia-telangiectasia that enrolled 17 patients across Germany, Spain, the United Kingdom, and the United States. The registered primary endpoint was Clinical Impression of Change in Severity, a blinded rater assessment comparing performance on the 9-Hole Peg Test or 8-Meter Walk Test against baseline, evaluated in a modified intention-to-treat population. Secondary endpoints included the Scale for the Assessment and Rating of Ataxia, the Spinocerebellar Ataxia Functional Index, and EQ-5D quality-of-life scores. Posted safety data from the parent study and its extension phase show one death recorded during the extension phase, among 1 serious adverse event out of 17 at-risk participants in the initial treatment period and 2 serious adverse events out of 13 at-risk participants during the extension. NCT03759678

The status change

The trial moved from Active, not recruiting to Terminated on March 25, 2026, the same day its results were first posted to the registry. Its primary completion date shifted six times over the study's life, moving from July 2020 to a final date of February 11, 2025, a cumulative delay of roughly 55 months from the original target. The study's completion date, separate from primary completion, is listed as October 27, 2025. Results being posted the same day the trial was marked Terminated indicates the study had reached its data endpoint and closed out administratively, rather than stopping short for a safety or futility reason disclosed in the record. NCT03759678

The competitive field

No other program has reached regulatory review for ataxia-telangiectasia. IntraBio's own Phase 3 study of the same drug, N-acetyl-L-leucine, is listed with a completion target of December 2027 and uses the Scale for the Assessment and Rating of Ataxia as its outcome measure. Beyond IntraBio's own programs, the broader ataxia-telangiectasia trial field includes early-stage studies of different mechanisms, including an ATR inhibitor and an ATM inhibitor in DNA-damage-repair programs, none of which target the same drug class or have reached a regulatory filing. That leaves this filing without a direct approved comparator: the FDA's evaluation will rest on how convincingly the trial's endpoint results, drawn from a 17-patient population, support extending an already-approved drug's label to a disease with no existing treatment standard. IntraBio

This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.