01/21/2026
From Brad Margus, Founder, Volunteer Board Chair and A-T Dad
Dear A-T families, friends, and supporters,
I want to share an important update with you.
This morning, a company called IntraBio announced positive results from its pivotal Phase III clinical trial of a drug called N-acetyl-L-leucine (also known as levacetylleucine or NALL) in 70 children and adults with ataxia-telangiectasia (A-T). For those of us who live with this disease every day as parents, patients, siblings, and caregivers, this is genuinely encouraging news.
Having spent a lot of time supporting clinical research through the A-T Children’s Project and working in the biotech industry, I approach trial results with caution. Neurodegenerative diseases are especially challenging. Many ideas that look promising in the lab, or even in small clinical studies, ultimately fail when tested rigorously. That context matters here, because what makes this result stand out is not hype, but evidence.
What was studied?
The trial, known as IB1001-303, was a randomized, placebo-controlled, double-blind crossover study. Each participant received both placebo and active drug at different times, allowing every child or adult to serve as their own control. In a rare and highly variable disease like A-T, that design substantially increases confidence in the results.
Participants were treated for 12 weeks, longer than in many earlier studies, and outcomes were measured using well-established neurological scales, including the Scale for the Assessment and Rating of Ataxia (SARA), which evaluates balance, coordination, speech, and gait.
What did the trial show?
Treatment with levacetylleucine led to statistically significant and clinically meaningful improvements compared with placebo. The study met its primary endpoint on the SARA scale and also met key secondary endpoints, with a favorable safety and tolerability profile. No drug-related serious side effects were reported. Based on these results, regulatory submissions in the U.S. and Europe are now planned.
Numbers and p-values matter to regulators, but families like mine ask a different question: does this translate into something real? Better balance and coordination. Clearer speech. More stamina. A bit more independence. While no single trial answers every question, this study provides strong evidence that this drug can meaningfully improve neurological function in A-T.
Why does this result feel different?
Over the past few years, several metabolic or anti-inflammatory approaches have shown encouraging signals in A-T. Trials of triheptanoin and nicotinamide riboside (NR) reported improvements in motor scores and other measures (biomarkers), but those studies were early-stage and largely open-label, without placebo control. Similarly, low-dose steroid approaches have shown trends toward benefit, but the most rigorous completed Phase III study to date did not meet its primary endpoint.
What distinguishes this levacetylleucine result is that it comes from a well-controlled, blinded Phase III trial that clearly met its prespecified endpoints. That doesn’t diminish the importance of earlier or parallel approaches (many helped point the field in the right direction, and their benefits may become clearer over time), but it does mean this evidence carries greater weight and confidence.
Why this is encouraging.
Levacetylleucine is taken by mouth and is chemically derived from the natural amino acid leucine, modified to give it drug-like properties. In A-T, it’s thought to support stressed neurons by improving mitochondrial energy balance and modulating ion channel activity, helping neurons function better despite the underlying genetic damage.
This isn’t a gene-correcting therapy, and it doesn’t “cure” A-T. But A-T is a progressive disease, and even stabilizing or modestly improving neurological function can matter enormously to quality of life. Importantly, after the blinded trial ends, participants can continue on the active drug in a longer-term open-label extension, allowing researchers to see whether benefits persist or grow with sustained treatment.
Families affected by A-T have learned, often painfully, to be skeptical. We also know that people respond to medicines differently, and not every child or young adult with A-T will benefit in the same way. Still, careful optimism feels appropriate here.
What comes next.
Regulatory review still lies ahead, and access will ultimately depend on decisions by health authorities. Real-world impact always matters more than any single study. But for the first time, there’s credible Phase III evidence that a therapy can make a meaningful difference for people with A-T.
I’m deeply grateful to the patients and families who chose to participate in this trial, to the clinicians around the world who ran a careful and demanding study, to our team at the A-T Children’s Project as well as other international A-T organizations who have helped with recruiting and in many other ways, and to the IntraBio team for pushing this work forward. Progress like this doesn’t happen by accident; it happens because a community steps up and supports it.
For families eager to make life better for their kids, and for clinicians who have long had no disease-specific therapies to offer, this feels like real progress. It’s not the end of the journey, but it is an important step forward.
We promise to keep you posted as we learn more about when the drug might become available for all A-T patients.
With gratitude and continued hope,
-Brad
AUSTIN, Texas–(BUSINESS WIRE)–IntraBio Inc. today announced positive topline results from its pivotal Phase III IB1001-303 clinical trial, “Effects of N-Acetyl-L-Leucine on Ataxia-Telangiectasia (A-T): A Randomized, Placebo-Controlled, Double-Blind, Crossover Study” (NCT06673056) evaluating ...
