Summary

Levacetylleucine was approved in the United States in September 2026 for ataxia in adults and pediatric patients with ataxia-telangiectasia weighing at least 15 kg, and the FDA describes it as the first treatment approved for ataxia in this disease. The indication is defined by diagnosis and body weight, and the label lists no contraindications. The pivotal trial enrolled 73 participants aged 4 years or older with genetically confirmed disease and a SARA score of 7 to 34; participants younger than 4 years, asymptomatic participants, and participants with advanced disease who could not complete functional assessments were excluded. The trial authors propose levacetylleucine as a first-line, foundational therapy. Dosing follows body weight (2 g, 3 g, or 4 g per day in two or three doses) as an oral suspension taken with or without food or given through a gastrostomy tube, and the label directs patients and caregivers to the Instructions for Use. The approved indication covers ataxia; published guidance continues to recommend multidisciplinary supportive care for immunodeficiency, respiratory disease, nutrition, and malignancy surveillance. Pregnancy status is verified before initiation in females of reproductive potential, and concomitant N-acetyl-DL-leucine and N-acetyl-D-leucine are avoided. The 12-week controlled period measured a symptomatic effect that was lost during the subsequent placebo period, and long-term data depend on the ongoing open-label extension. The manufacturer stated that the product was commercially available at approval.

First treatment approved for ataxia in ataxia-telangiectasia

“Today’s approval makes Aqneursa the first treatment approved for ataxia in patients with ataxia-telangiectasia.” (opens the source at this quote in a new tab)

Position proposed by the pivotal trial investigators

“Given that ataxia-telangiectasia is a debilitating, prematurely fatal condition with no approved drug, if approved, levacetylleucine could be considered as the first-line, foundational therapy for the treatment of ataxia-telangiectasia.” (opens the source at this quote in a new tab)

Population studied and populations excluded from the pivotal trial

“Eligible patients were aged 4 years or older with a genetically confirmed diagnosis of ataxia-telangiectasia; had a SARA score of 7–34 and were either within the 2–7 range of the gait subtest of the SARA scale or were able to perform the 9-hole peg test with their dominant hand in a time of 20–150 sec; and weighed 15 kg or more at screening.” (opens the source at this quote in a new tab)
“Second, the focus on symptomatic endpoints excluded patients younger than 4 years, asymptomatic patients, or patients with advanced disease states who would not be reliably able to complete functional assessments.” (opens the source at this quote in a new tab)

Route of administration and care setting

“The recommended dosage of AQNEURSA to be administered orally, with or without food, is based on the patient’s actual body weight (kg), as shown in Table 1” (opens the prescribing information at this quote)
“For patients who have a G-tube (French size 12 or larger) in place, administer AQNEURSA as follows:” (opens the prescribing information at this quote)
“Advise the patient and/or caregiver to read the FDA-approved patient labeling (Instructions for Use).” (opens the prescribing information at this quote)

Use with racemic acetylleucine

“Avoid concomitant use of AQNEURSA with N-acetyl-DL-leucine and N-acetyl-D-leucine. The D-enantiomer, N-acetyl-D-leucine, competes with levacetylleucine for monocarboxylate transporter uptake, which may reduce the levacetylleucine efficacy.” (opens the prescribing information at this quote)

Commercial availability at approval

“AQNEURSA is commercially available now” (opens the source at this quote in a new tab)

Aqneursa (levacetylleucine)

Place in treatment, anticipated use, and care setting