Levacetylleucine

Pivotal Phase III trial authorized to proceed in every region where IntraBio submitted regulatory applications: the U.S., U.K., EU, and Switzerland Twelve multinational clinical trial sites are now being activated, with recruitment to begin immediately upon activation The CACNA1A-related disorders trial will utilize a 12-week, randomized, double-blind, placebo-controlled crossover clinical trial design, the same design used in IntraBio’s prior pivotal clinical programs for AQNEURSA® (levacetylleucine) for Niemann Pick Disease type C (approved U.S; authorized EU) and the company’s sNDA for Ataxia-Telangiectasia (FDA Priority Review, PDUFA September 19, 2026) AUSTIN, Texas--(BUSINESS WIRE)--IntraBio Inc., a global biopharmaceutical company developing therapies for neurological diseases, today announced that its pivotal Phase III trial of levacetylleucine in patients with CACNA1A-related disorders has been authorized to proceed across all participating regions, including the U.S., the U.K., the European Union, and Switzerland. Twelve multinational sites are now being activated and will begin recruitment as activation completes. CACNA1A-related disorders are rare, inherited neurological conditions for which no therapies are currently approved. The Phase III study (IB1001-304) is a 12-week, randomized, double-blind, placebo-controlled crossover trial designed to assess the safety, tolerability, and efficacy of levacetylleucine in this population. The study uses the same design as the pivotal trial that supported U.S. FDA and European Commission approval of AQNEURSA® (levacetylleucine) for the neurological manifestations of Niemann-Pick disease type C (NPC), and that supported IntraBio's positive Phase III study in Ataxia-Telangiectasia (A-T). The supplemental New Drug Application for A-T is currently under FDA Priority Review, with a PDUFA target action date of September 19, 2026. "We are now applying the same pivotal trial design that earned FDA and European Commission approval of AQNEURSA in Niemann-Pick disease type C, and that supported our recent Priority Review filing in Ataxia-Telangiectasia, to a third rare neurological indication," said Mallory Factor, President and Chief Executive Officer of IntraBio. "CACNA1A patients have waited a long time for a therapy developed specifically for them, and we intend to move as quickly as the science allows." “Until now, there have been no disease-specific clinical trials for CACNA1A-related disorders and there is no approved disease-specific therapy anywhere in the world,” said PD Dr. med. Tatiana Brémovà-Ertl, PhD, Principal Investigator from the University of Bern. “The clinical evidence generated to date with levacetylleucine in rare neurological diseases is very exciting, and this pivotal Phase III study represents an important opportunity to evaluate whether levacetylleucine may offer a meaningful treatment option for patients and families affected by these serious and often debilitating conditions.” About IB1001-304 The CACNA1A pivotal Phase III trial, IB1001-304, titled "Pivotal Study of N-acetyl-L-leucine for CACNA1A," is a randomized, double-blind, placebo-controlled, crossover study evaluating levacetylleucine in patients with CACNA1A-related disorders. The study is designed to assess safety, tolerability, and efficacy compared with placebo over a 12-week treatment period and will be conducted across 12 multinational sites in the U.S., U.K., EU, and Switzerland. Sites are currently being activated to begin recruitment. Levacetylleucine is investigational for the treatment of CACNA1A-related disorders and has not been approved by the FDA, MHRA, EMA, Swissmedic, or any other regulatory authority for this indication. The study is registered on ClinicalTrials.gov as NCT07221292 and under EudraCT Number 2025-523828-51. About CACNA1A-Related Disorders CACNA1A-related disorders are rare, inherited neurological conditions caused by pathogenic variants in the CACNA1A gene, which plays a central role in calcium channel function in the nervous system. CACNA1a-related disorders are estimated to affect approximately 1 in 11,700 individuals. Symptoms may include progressive or episodic ataxia, impaired coordination, abnormal eye movements, speech impairment, seizures, migraine, and functional disability. There are currently no approved therapies for CACNA1A-related disorders. About AQNEURSA® (levacetylleucine) U.S. Indication AQNEURSA® (levacetylleucine) is approved in the United States for the treatment of neurological manifestations of Niemann-Pick disease type C (NPC) in adults and pediatric patients weighing at least 15 kg. U.S. IMPORTANT SAFETY INFORMATION Embryo-Fetal Toxicity Based on findings from animal reproduction studies, AQNEURSA may cause embryo-fetal harm when administered during pregnancy. The decision to continue or discontinue AQNEURSA during pregnancy should consider the patient's clinical need, the potential drug-related risks to the fetus, and the potential adverse outcomes from untreated maternal disease. Pregnancy and Lactation: For females of reproductive potential, confirm the patient is not pregnant prior to initiating treatment. Advise use of effective contraception 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; the developmental and health benefits of breastfeeding should be weighed against clinical need and potential risks to the infant. Adverse Reactions The most common adverse reactions (incidence ≥5% and greater than placebo) are abdominal pain, dysphagia, upper respiratory tract infections, and vomiting. Drug Interactions Avoid concomitant use of AQNEURSA with N-acetyl-DL-leucine or N-acetyl-D-leucine. The D-enantiomer competes with levacetylleucine for monocarboxylate transporter uptake, potentially reducing efficacy. Monitor more frequently for P-gp substrate-related adverse reactions when used concomitantly with AQNEURSA, as AQNEURSA inhibits P-gp; the clinical significance of this finding has not been fully characterized. To report SUSPECTED ADVERSE REACTIONS, contact IntraBio Inc. at 1-833-306-9677 or FDA at 1-800-FDA-1088 or visit . Please see Full U.S. Prescribing Information for AQNEURSA at aqneursahcp.com . EU (EMA) Indication AQNEURSA® is authorized in the European Union for the treatment of neurological manifestations of Niemann-Pick disease type C in adults and children aged 6 years and older weighing at least 20 kg, either in combination with miglustat or as monotherapy in patients who cannot tolerate miglustat. See EMA Indication and Important Safety Information. About IntraBio IntraBio Inc. is a global biopharmaceutical company headquartered in Austin, Texas, focused on developing and commercializing targeted therapies for rare and common neurological, neurodevelopmental, and mitochondrial diseases. IntraBio's platform technologies are built on decades of scientific research and collaboration with leading institutions worldwide, including the University of Oxford and the University of Munich. Contacts MEDIA & INVESTOR CONTACT Cass Fields | Vice President, External Affairs ccfields@intrabio.com |

Pivotal Phase III Trial Meets All Primary and Key Secondary Endpoints with High Statistical Significance Levacetylleucine Could Become the First-Ever FDA-Approved Treatment for Ataxia-Telangiectasia FDA accepts sNDA for AQNEURSA® (levacetylleucine) for Ataxia-Telangiectasia — a rare, progressive neurodegenerative disease with no currently approved treatments Priority Review granted; PDUFA target action date of 19 September 2026 Pivotal Phase III trial (IB1001-303) met primary and key secondary endpoints with high statistical significance, demonstrating clinically meaningful improvements in neurological signs, symptoms, and function in pediatric and adult patients If approved, AQNEURSA would be the first FDA-approved therapy for A-T AUSTIN, Texas--(BUSINESS WIRE)--IntraBio Inc., a global biopharmaceutical company focused on developing and commercializing therapies for neurological diseases, today announced that the U.S. Food and Drug Administration (FDA) has accepted for review its supplemental New Drug Application (sNDA) for AQNEURSA® (levacetylleucine) for the treatment of Ataxia-Telangiectasia (A-T) in adults and pediatric patients. The FDA simultaneously granted Priority Review and assigned a PDUFA target action date of 19 September 2026. If approved, AQNEURSA would become the first FDA-approved treatment for A-T. “Today’s announcement represents a profound step forward — not just for IntraBio, but for the thousands of patients and families living with Ataxia-Telangiectasia who have waited far too long for a treatment option. Our Phase III trial didn’t just meet the bar — it cleared it with high statistical significance across both primary and key secondary endpoints, delivering meaningful improvements in neurological function. The FDA’s Priority Review designation reflects the urgency of this unmet need, and we are fully committed to working with the agency to make AQNEURSA the first approved therapy for A-T as swiftly as possible.” — Mallory Factor, President and Chief Executive Officer, IntraBio The submission is supported by data from a pivotal Phase III clinical trial evaluating levacetylleucine in adult and pediatric patients with A-T. In this randomized, double-blind, placebo-controlled crossover study, levacetylleucine met its primary endpoint and all key secondary endpoints with high statistical significance, demonstrating clinically meaningful improvements in neurological signs, symptoms, and functioning. The compound was generally safe and well-tolerated, with no drug-related serious adverse events observed — consistent with its established safety profile. ABOUT ATAXIA-TELANGIECTASIA (A-T) Ataxia-Telangiectasia is a rare, inherited, progressive neurodegenerative disorder that typically manifests in early childhood. A-T is estimated to affect 1 in 40,000-100,000 people. It is characterized by cerebellar degeneration leading to worsening loss of coordination, impaired speech, abnormal eye movements, and eventual wheelchair dependence. Many patients also develop telangiectasia, immune deficiency with recurrent and potentially life-threatening infections, pulmonary disease, and a significantly elevated risk of cancer. There are currently no FDA-approved therapies for A-T. ABOUT AQNEURSA® (LEVACETYLLEUCINE) U.S. Indication AQNEURSA® (levacetylleucine) is approved in the United States for the treatment of neurological manifestations of Niemann-Pick disease type C (NPC) in adults and pediatric patients weighing at least 15 kg. U.S. IMPORTANT SAFETY INFORMATION Embryo-Fetal Toxicity Based on findings from animal reproduction studies, AQNEURSA may cause embryo-fetal harm when administered during pregnancy. The decision to continue or discontinue AQNEURSA during pregnancy should consider the patient’s clinical need, the potential drug-related risks to the fetus, and the potential adverse outcomes from untreated maternal disease. Pregnancy and Lactation For females of reproductive potential, confirm the patient is not pregnant prior to initiating treatment. Advise use of effective contraception 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; the developmental and health benefits of breastfeeding should be weighed against clinical need and potential risks to the infant. Adverse Reactions The most common adverse reactions (incidence ≥5% and greater than placebo) are abdominal pain, dysphagia, upper respiratory tract infections, and vomiting. Drug Interactions Avoid concomitant use of AQNEURSA with N-acetyl-DL-leucine or N-acetyl-D-leucine . The D-enantiomer competes with levacetylleucine for monocarboxylate transporter uptake, potentially reducing efficacy. Monitor more frequently for P-gp substrate-related adverse reactions when used concomitantly with AQNEURSA, as AQNEURSA inhibits P-gp; the clinical significance of this finding has not been fully characterized. To report SUSPECTED ADVERSE REACTIONS, contact IntraBio Inc. at 1-833-306-9677 or FDA at 1-800-FDA-1088 or visit . Please see Full U.S. Prescribing Information for AQNEURSA at aqneursahcp.com . EU (EMA) Indication AQNEURSA® is authorized in the European Union for the treatment of neurological manifestations of Niemann-Pick disease type C in adults and children aged 6 years and older weighing at least 20 kg, either in combination with miglustat or as monotherapy in patients who cannot tolerate miglustat. See EMA Indication and Important Safety Information . ABOUT INTRABIO IntraBio Inc. is a global biopharmaceutical company headquartered in Austin, Texas, focused on developing and commercializing targeted therapies for rare and common neurological, neurodevelopmental, and mitochondrial diseases. IntraBio’s platform technologies are built on decades of scientific research and collaboration with leading institutions worldwide, including the University of Oxford and the University of Munich. Contacts MEDIA & INVESTOR CONTACT Cass Fields | Vice President, External Affairs & Marketing ccfields@intrabio.com |