A Phase 4 interventional study of Avalglucosidase alfa in Glycogen Storage Disease Type II and Pompe's Disease, sponsored by Genzyme, a Sanofi Company. Recruiting at 1 site in China. Open to participants aged Up to 17 Years. Per ClinicalTrials.gov, last updated 2026-03-23.
Sponsored by Genzyme, a Sanofi Company (part of Sanofi) · Phase 4, Interventional, and Treatment
This is a single group, 52-week treatment, Phase 4, open-label, single-arm study to assess the safety and efficacy of avalglucosidase alfa IV infusion in male and female Chinese participants with IOPD who are treatment-naïve or were previously treated with ERT.
Study details include:
The study duration: total study duration is approximately 64 weeks.
162 studies on the registry are indexed under Glycogen Storage Disease Type II; 34 are open to participants now.
This study's planned enrollment of 13 is below the median of 20 across 89 interventional studies indexed under Glycogen Storage Disease Type II.
Browse Glycogen Storage Disease Type II studies →Genzyme, a Sanofi Company is the lead sponsor of 308 studies on the registry; 5 are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 19 (76%) have results posted.
First submitted after Genzyme became part of Sanofi.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
Exclusion Criteria: Participants are excluded from the study if any of the following criteria apply:
The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Avalglucosidase alfa will be administered by IV infusion following reconstitution and dilution at a dose of 20 mg/kg body weight qow
Drug: Avalglucosidase alfa
Pharmaceutical form: Sterile lyophilized powder Route of administration: IV infusion
Also known as: GZ402666, Nexviazyme
Incidence of AEs, SAEs, AESIs including IARs during the TE period
Time frame: From baseline to Week 56
Abnormality in clinical laboratory, vital signs, and ECG parameters during the TE period
Time frame: From baseline to Week 56
Proportion of participants who are alive and free of invasive ventilation at Week 52
Time frame: At Week 52
Change from baseline to Week 52 in LVM Z score evaluated by echocardiography
Time frame: From baseline to Week 52
The absolute change in body growth Z scores from baseline to Week 52
Time frame: From baseline to Week 52
The percentiles of the body growth Z scores changes from baseline to Week 52
Time frame: From baseline to Week 52
Change from baseline to Week 52 in distance walked during six-minute walk test (6MWT) (in applicable participants)
Time frame: From baseline to Week 52
Change from baseline to Week 52 in quick motor function test (QMFT) score (in applicable participants)
Time frame: From baseline to Week 52
Number of motor development milestones achieved as evaluated by Motor Milestone Checklist at Week 52
Time frame: At Week 52
Plan to share: Yes — Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
Started May 2025 (actual). Primary completion is estimated for May 2028, 35 months after the start.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Avalglucosidase alfa
Glycogen Storage Disease Type II →