IntraBio's AQNEURSA nears FDA verdict as first drug for A-T
The Phase 3 trial already showed a 1.88-point SARA benefit over placebo with p<0.001, and the FDA's September 19 priority review decides if that becomes the first approved A-T therapy.
Executive Summary
- The FDA is set to decide by September whether to approve the first therapy for a rare, progressive neurological disease that currently has none, built on trial data that already cleared its primary endpoint.
- The pivotal study reported a statistically significant improvement in ataxia symptoms over placebo, with the sponsor also reporting all key secondary endpoints met and no drug-related serious adverse events.
- Because the same drug is already approved in the United States for a different neurological condition, the regulatory question centers on extending an established safety and efficacy record rather than establishing it from scratch.
- The label's eventual scope, including whether pediatric and adult populations are treated identically, remains the swing factor for how broadly an approval would reach.
The catalyst
The FDA accepted IntraBio's supplemental New Drug Application for AQNEURSA in Ataxia-Telangiectasia (A-T) and granted Priority Review, setting a target action date of September 19, 2026. If approved, AQNEURSA would become the first FDA-approved treatment for A-T, a rare inherited neurodegenerative disorder estimated to affect 1 in 40,000 to 100,000 people that causes progressive loss of coordination, impaired speech, immune deficiency, and elevated cancer risk. IntraBio Chief Executive Mallory Factor said the Phase 3 trial "didn't just meet the bar" but "cleared it with high statistical significance across both primary and key secondary endpoints". FDAFDA Accepts sNDA and Grants Priority Review to AQNEURSA® for Ataxia-TelangiectasiaMay 19, 2026
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The trial and its result
The submission rests on NCT06673056, a randomized, double-blind, placebo-controlled crossover trial enrolling 60 patients aged 4 and older with genetically confirmed A-T, run across the United States, Germany, Slovakia, the United Kingdom, Spain, and Switzerland. The registered primary endpoint was the Scale for the Assessment and Rating of Ataxia (SARA), a clinician-scored measure of coordination and gait. The trial reported a mean SARA change of -1.92 for levacetylleucine versus -0.14 for placebo, a between-arm difference of -1.88 points at p<0.001, published in The Lancet Neurology. Five secondary endpoints, including the EQ-5D quality-of-life scale and the International Cooperative Ataxia Rating Scale, were also reported met. The compound was described as generally safe and well-tolerated, with no drug-related serious adverse events observed. NCT06673056+1A Pivotal Study of N-Acetyl-L-Leucine on Ataxia-Telangiectasia (A-T)NCT06673056FDA Accepts sNDA and Grants Priority Review to AQNEURSA® for Ataxia-TelangiectasiaMay 19, 2026
Why the bar is lower
AQNEURSA is already approved in the United States for neurological manifestations of Niemann-Pick disease type C in patients weighing at least 15 kg. That existing approval means the FDA's decision in A-T turns on whether the disclosed SARA effect and safety data support extending use to a second neurological indication, not on establishing the drug's basic safety profile for the first time. The most common adverse reactions in the existing label, abdominal pain, difficulty swallowing, upper respiratory infections, and vomiting, occurring in at least 5% of patients and more often than with placebo, give the agency an established tolerability baseline to weigh the A-T data against. FDAFDA Accepts sNDA and Grants Priority Review to AQNEURSA® for Ataxia-TelangiectasiaMay 19, 2026
The trial's operational footing
The trial reached its 60-patient enrollment target with no change from its original target, moved from Recruiting to Active, not recruiting in July 2025, and its protocol has logged one eligibility-criteria amendment and no changes to its primary completion date. Ataxia-Telangiectasia carries limited competing clinical activity: across trials search results for the indication, only one other program uses the same modality, an earlier IntraBio Phase 2 study of the same compound (NCT03759678), alongside a handful of DNA-damage-repair-targeted oncology trials in related genetic conditions that address a different clinical question. No competitor trial in A-T shares AQNEURSA's approach to symptomatic ataxia treatment, leaving the regulatory decision as the dominant near-term event for this specific therapeutic hypothesis. NCT06673056A Pivotal Study of N-Acetyl-L-Leucine on Ataxia-Telangiectasia (A-T)NCT06673056
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.