FDA Approves IntraBio's AQNEURSA (levacetylleucine) for Ataxia-Telangiectasia, the First Treatment Anywhere for the Disease
核心洞察
The FDA approved AQNEURSA (levacetylleucine) for ataxia in adults and pediatric patients with ataxia-telangiectasia (搜索) weighing at least 15 kg, the first approved treatment for the disease worldwide.
Approval was supported by the pivotal Phase 3 IB1001-303 crossover trial, in which AQNEURSA improved SARA scores versus placebo by 1.9 points (95% CI -2.7 to -1.1; p<0.001).
The trial enrolled 73 patients aged 4 to 50 years with genetically confirmed A-T across 10 sites in six countries, and 96% completed both treatment periods.
The U.S. Food and Drug Administration (搜索) has approved AQNEURSA (levacetylleucine) for the treatment of ataxia in adult and pediatric patients with ataxia-telangiectasia (搜索) (A-T) weighing 15 kg or more, IntraBio Inc. (搜索) announced on September 18, 2026. The decision makes the orally administered suspension the first and only drug approved for A-T anywhere in the world, and the second FDA-approved indication for the molecule.
A-T is a rare, progressive and prematurely fatal autosomal-recessive neurodegenerative disorder that affects an estimated 1 in 40,000 people. It is caused by biallelic pathogenic variants in the ATM gene (搜索) and is characterized by progressive cerebellar degeneration that produces worsening ataxia affecting gait, truncal control, eye movements, balance, speech and hand coordination. Symptoms typically appear in early childhood and also include difficulty swallowing and loss of fine and gross motor function. The disease features immunodeficiency, sinopulmonary infections and a substantially increased risk of malignancy, particularly of lymphoid origin. Until this approval, there were no approved treatments for A-T anywhere in the world.
"This is a historic day for the A-T community and the patients and caregivers who have coped for decades without a treatment approved specifically for A-T," said Brad Margus, founder of the A-T Children's Project. "With today's FDA decision, those impacted by A-T have a treatment option that has demonstrated benefit across a range of A-T symptoms, including those that affect daily life for patients and their loved ones."
Pivotal Phase 3 Data
The approval is supported by the pivotal IB1001-303 study (NCT06673056), a randomized, double-blind, placebo-controlled crossover trial that enrolled 73 patients aged 4 to 50 years with genetically confirmed A-T across 10 clinical trial sites in Germany, Slovakia, Spain, Switzerland, the United Kingdom and the United States. Seventy patients, or 96%, completed the study and received both placebo and AQNEURSA. Results were published in the July 2026 issue of The Lancet Neurology.
The trial met its primary efficacy endpoint, with key secondary endpoints supportive of the primary result. AQNEURSA produced a statistically significant improvement versus placebo on the Scale for the Assessment and Rating of Ataxia (SARA), with a treatment difference of -1.9 points (95% CI: -2.7, -1.1; two-sided p<0.001).
The primary outcome assessed by the FDA was the functional SARA (fSARA), a modified version comprising the gait, sitting, stance and speech disturbance domains. Patients who received AQNEURSA showed a greater improvement in fSARA score, with a mean treatment difference of -0.6 (95% CI: -0.9, -0.2; two-sided p<0.001). According to IntraBio, the study showed functional benefits important to everyday life that were evident within 12 weeks, and improvement was consistent across secondary endpoints and prespecified subgroups, including pediatric and adult patients, with no evidence of heterogeneity in treatment effect across the population.
Safety Profile
AQNEURSA was well tolerated in the trial. No treatment-related serious adverse events and no deaths occurred, and no patients discontinued because of a treatment-related adverse event. The most common adverse reactions in A-T, defined as an incidence of 5% or greater and greater than placebo, were fall, skin laceration and urinary tract infection.
The label carries an embryo-fetal toxicity warning based on findings from animal reproduction studies. For females of reproductive potential, pregnancy status should be verified before initiating treatment, and effective contraception is advised during treatment and for 7 days after the last dose if AQNEURSA is discontinued. There are no data on the presence of levacetylleucine or its metabolites in human or animal milk.
IntraBio also advises avoiding concomitant use of AQNEURSA with N-acetyl-DL-leucine or N-acetyl-D-leucine. The D-enantiomer, N-acetyl-D-leucine, competes with levacetylleucine for monocarboxylate transporter uptake, which may reduce levacetylleucine efficacy. More frequent monitoring for P-gp substrate-related adverse reactions is recommended with concomitant use, as AQNEURSA inhibits P-gp, although the clinical significance of this finding has not been fully characterized.
Mechanism and Prior Approval
AQNEURSA is a first-in-class, chemically modified amino acid taken orally as a suspension. The distinct molecular target for the drug in the treatment of NPC or A-T is unknown. The proposed mechanism of action is normalization of glucose metabolism, which is correlated with enhanced cerebellar activity. The drug is designed to enter enzyme-controlled pathways to correct metabolic dysfunction, improve lysosomal function and enhance mitochondrial function and ATP production. In preclinical studies, AQNEURSA normalized lysosomal function, reduced substrate accumulation, improved mitochondrial ATP production and reduced neuroinflammation, addressing shared downstream metabolic dysfunction rather than a single genetic defect.
The FDA initially approved AQNEURSA in September 2024 for the treatment of neurological manifestations of Niemann-Pick disease type C (搜索) in adults and pediatric patients weighing 15 kg or more. In NPC, the most common adverse reactions are abdominal pain, dysphagia, upper respiratory tract infections and vomiting.
"Today marks a tremendous milestone for the A-T community and IntraBio," said Mallory Factor, chief executive officer of IntraBio. "As the first FDA-approved drug for the treatment of Ataxia-Telangiectasia (搜索), AQNEURSA now offers the potential to make meaningful differences in the lives of thousands of patients and their families who have lacked options to treat the diverse and debilitating array of symptoms caused by A-T."
Access and Pipeline
AQNEURSA is commercially available now. IntraBio offers a Patient Support Service, AQNEURSA Cares, which includes financial support to reduce or eliminate out-of-pocket costs for qualifying patients, access to financial and educational resources, and a dedicated team of specialists to help with starting treatment, questions about taking the medication and navigating insurance coverage.
IntraBio, a U.S. biopharmaceutical company focused on novel drugs for rare and common neurological diseases, is conducting a Phase III trial, IB1001-304, in CACNA1A-related disorders (搜索). That group of rare inherited neurological conditions has an estimated incidence of approximately one in 11,700, corresponding to approximately 30,000 individuals in the United States and an estimated 690,000 worldwide, and there are currently no approved therapies anywhere in the world.