The FDA has approved Aqneursa (levacetylleucine), making it the first treatment ever specifically indicated for ataxia-telangiectasia (A-T) — a rare, inherited neurodegenerative disorder that causes progressive cerebellar degeneration, affecting gait, balance, speech, coordination, and eye movements. The approval applies to adults and pediatric patients weighing at least 15 kg, and adds a second FDA-approved indication for the oral amino acid-based drug, which was first cleared in 2024 for Niemann-Pick disease type C.

The green light was supported by the phase 3 IB1001-303 trial — a randomized, double-blind, placebo-controlled crossover study enrolling 73 patients aged 4–50 years with genetically confirmed A-T across 10 sites in the US and Europe. The drug showed statistically significant improvements on ataxia rating scales, with no treatment-related serious adverse events, deaths, or discontinuations reported.

Key Takeaways:

• SARA score improvement: treatment difference of −1.9 points vs. placebo (95% CI, −2.7 to −1.1; P <.001)
• Functional SARA improvement: mean treatment difference of −0.6 points vs. placebo (95% CI, −0.9 to −0.2; P <.001)
• Most common adverse reactions (≥5%): fall, skin laceration, and urinary tract infection
• Concomitant use with N-acetyl-DL-leucine or N-acetyl-D-leucine should be avoided due to potential embryo-fetal harm based on animal data

Why it matters: A-T has long had no approved pharmacologic therapies, leaving patients and families with only supportive care options. This approval gives neurologists and ataxia specialists a concrete, evidence-backed treatment to discuss with patients — a meaningful step forward for a disease with significant unmet need.