AB-1009 gene therapy for adults with late-onset Pompe disease

A Single-Arm, Open-Label, Dose-Escalation Study to Evaluate the Safety, Tolerability and Efficacy of a Single Intravenous Infusion of AB-1009 in Adult Participants With Late Onset Pompe Disease (LOPD)

This study tests a one-time IV gene therapy (AB-1009) to try to restore GAA enzyme activity and improve muscle and breathing function in adults with late-onset Pompe disease who are already on enzyme replacement therapy.

Quick facts

• Phase: Phase1; Phase2
• Study type: Interventional
• Enrollment: 12 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: AskBio Inc (Industry-sponsored)
• Locations: 10 sites (Phoenix, Arizona and 9 other locations)
• Trial ID: NCT07282847 on ClinicalTrials.gov

What this trial studies

This open-label, single-arm, dose-escalation study will enroll up to 12 adults with late-onset Pompe disease to receive one intravenous infusion of AB-1009 and be followed for safety and signs of clinical benefit. Participants are assigned to one of two dose cohorts (1.0E13 vg/kg or 1.5E13 vg/kg). Eligibility requires confirmed GAA deficiency and at least six months of prior enzyme replacement therapy, with respiratory and walking function within specified ranges. The main observation period is 52 weeks after dosing, with long-term follow-up extending for approximately four years to monitor durability and late safety signals.

Who should consider this trial

Good fit: Adults (≥18 years) with genetically or enzymatically confirmed late-onset Pompe disease who have been on enzyme replacement therapy for at least six months, have upright FVC 30–80% predicted, and can walk at least 100 meters are the intended candidates.

Not a fit: Patients with severe cardiomyopathy (LVEF <40%), those who do not meet the respiratory or mobility thresholds, children, or people not on the required prior ERT are unlikely to be eligible or benefit from this study.

Why it matters

Potential benefit: If successful, a single AB-1009 infusion could provide durable GAA enzyme expression that reduces reliance on regular enzyme replacement infusions and stabilizes or improves muscle and respiratory function.

How similar studies have performed: Early-phase AAV-based gene therapy programs for Pompe disease have shown promising preclinical results and limited clinical signals, but definitive, widely replicated clinical benefit has not yet been established.

Eligibility criteria

Inclusion Criteria:

1. Participant must be ≥18 years of age at the time of signing the informed consent form.
2. Confirmed GAA enzyme deficiency from any tissue source and/or confirmed biallelic GAA gene mutations.
3. Undergone enzyme replacement treatment (ERT) (either alglucosidase alfa (Lumizyme®) or avalglucosidase alfa-ngpt (Nexviazyme®)), for at least 6 months (at least 10 infusions) before signing the initial informed consent form. During the screening process, participants need to remain on their current ERT until close to dosing;
4. FVC in the upright position ≥30% and ≤80% of predicted;
5. Capable of walking at least 100 meters in the 6MWT (use of a cane, quad cane, or standard walker is permitted);
6. Contraceptive/barrier use by men and women requirements as per protocol.
7. Capable of giving informed consent and able to understand and comply with all study procedures.

Exclusion Criteria:

1. Severe cardiomyopathy, defined as left ventricular ejection fraction (LVEF) \<40% or New York Heart Association (NYHA) functional class 3 or above;
2. Require invasive mechanical ventilation, or rely on noninvasive ventilation during the day;
3. Intolerance to ERT or investigator-assessed intolerance to ERT, prior experience of serious ERT-related infusion-associated reactions (IARs);
4. Have known intrinsic liver diseases, including hepatitis, HIV-related liver disease, prior diagnosis of portal hypertension, splenomegaly, hepatic encephalopathy, severe fatty liver, cirrhosis or liver fibrosis ≥stage 2, ultrasound-identified liver neoplasms, or laboratory tests suggesting elevated alpha-fetoprotein. Patients with liver function tests including ALT or AST \>3× upper limit of normal (ULN) or any total bilirubin above ULN during screening will also be excluded;
5. Prior or ongoing medical condition(s), physical finding(s), assessment findings, or laboratory abnormality that, in the investigator's opinion, would impact participant's safety and compliance with the study procedures.
6. Have received gene therapy prior to screening;
7. Have received any systemic immunosuppressants (except inhalation or topical use) other than glucocorticoids or investigator-recommended immunosuppressants 30 days prior to screening through completion of screening, and/or known intolerance to immunosuppressants such as glucocorticoids;
8. Use of investigational drugs or drugs that could affect this study as evaluated by the investigator within 30 days prior to screening through completion of Week 52 or within 5 half-lives of the investigational drug (whichever is longer);
9. Have received any vaccine within 30 days prior to dosing;
10. Other conditions that make the participant not eligible for the study according to the investigator.

Where this trial is running

Phoenix, Arizona and 9 other locations

• Barrow Neurological Institute — Phoenix, Arizona, United States (Not_yet_recruiting)
• University of California, Irvine (UCI) — Irvine, California, United States (Recruiting)
• Stanford Neuroscience Health Center — Palo Alto, California, United States (Not_yet_recruiting)
• NYU Langone — New York, New York, United States (Not_yet_recruiting)
• Duke University — Durham, North Carolina, United States (Not_yet_recruiting)
• Oregon Health and Science University (OHSU) — Portland, Oregon, United States (Not_yet_recruiting)
• Hospital of the University of Pennsylvania — Philadelphia, Pennsylvania, United States (Recruiting)
• University of Pittsburgh Medical Center (UPMC) — Pittsburgh, Pennsylvania, United States (Not_yet_recruiting)
• University of Texas Southwest Medical Center — Dallas, Texas, United States (Not_yet_recruiting)
• Virginia Commonwealth University (VCU) — Richmond, Virginia, United States (Not_yet_recruiting)

Study contacts

• Study coordinator: AskFirst Patient Engagement

Conditions Pompe Disease; Pompe Disease Late-Onset; LOPD; Glycogen Storage Disease; Lysosomal Storage Diseases; Acid Maltase Deficiency; Acid Maltase Deficiency Disease; Gene Therapy