IntraBio Inc., an Austin, Texas-based biopharmaceutical company, has submitted a supplemental New Drug Application (sNDA) to the US FDA seeking approval of Aqneursa (levacetylleucine) for the treatment of ataxia-telangiectasia (A-T) in adults and pediatric patients. If approved for the new indication, Aqneursa would be the first-ever treatment for rare, progressive neurodegenerative disease.
The FDA has accepted the sNDA for review and granted Priority Review, assigning a PDUFA target action date of September 19, 2026.
The filing and clinical evidence
The sNDA is supported by data from the IB1001-303 Phase III trial, a randomized, double-blind, placebo-controlled crossover study evaluating levacetylleucine in adult and pediatric patients with A-T. The company said the trial met its primary endpoint and all key secondary endpoints with high statistical significance, demonstrating improvements in neurological signs, symptoms, and function. No drug-related serious adverse events were observed, consistent with the compound's established safety profile from its existing approved indication.
Aqneursa already holds US FDA approval for the treatment of neurological manifestations of Niemann-Pick disease type C (NPC) in adults and pediatric patients weighing at least 15 kg, and is authorized in the EU for NPC in adults and children aged six years and older weighing at least 20 kg. The A-T sNDA represents the first regulatory submission for levacetylleucine in this indication.
The disease and the unmet need
A-T is a rare inherited disorder caused by mutations in the ATM gene, which encodes a protein kinase central to DNA damage repair. The disease typically presents in early childhood with progressive cerebellar ataxia, leading to loss of coordination, dysarthria, oculomotor apraxia, and eventual wheelchair dependence. Beyond neurological deterioration, patients face immune deficiency, recurrent pulmonary infections, telangiectasia, and a substantially elevated lifetime cancer risk — predominantly leukemia and lymphoma. The condition is estimated to affect between 1 in 40,000 and 1 in 100,000 individuals.
The current standard of care remains entirely supportive. Immunoglobulin replacement manages antibody deficiency, while pulmonary physiotherapy and antibiotics target recurrent infections. No intervention has been approved to slow or modify the underlying neurodegeneration.