for people ages 3 years and up (full criteria)
study started
estimated completion



Primary Objective: To determine the effect of avalglucosidase alfa treatment on respiratory muscle strength measured by percent (%) predicted forced vital capacity (FVC) in the upright position, as compared to alglucosidase alfa. Secondary Objective: To determine the safety and effect of avalglucosidase alfa treatment on functional endurance (6-minute walk test, inspiratory muscle strength (maximum inspiratory pressure), expiratory muscle strength (maximum expiratory pressure), lower extremity muscle strength (hand-held dynamometry), motor function (Quick Motor Function Test), and health-related quality of life (Short Form-12).

Official Title

A Phase 3 Randomized, Multicenter, Multinational, Double-blinded Study Comparing the Efficacy and Safety of Repeated Biweekly Infusions of Avalglucosidase Alfa (neoGAA, GZ402666) and Alglucosidase Alfa in Treatment naïve Patients With Late-onset Pompe Disease


The duration of the study per participant will be up to approximately 6 years that will consist of a 14-day screening period (may be extended up to 8 weeks in pre-specified situations), a 49-week blinded treatment period (except for the subgroup of pediatric patients aged 3 to less than (<) 18 years enrolling directly in the open-label long-term follow-up phase), a 240-week open-label treatment period, and a 4-week post-treatment observation period.


Glycogen Storage Disease Type II;Pompe's Disease Glycogen Storage Disease Type II Glycogen Storage Disease Avalglucosidase alfa (GZ402666) Alglucosidase alfa (GZ419829)


You can join if…

Open to people ages 3 years and up


  • The participant has confirmed acid alpha-glucosidase (GAA) enzyme deficiency from any tissue source and/or 2 confirmed GAA gene mutations.
  • The participant must provide signed, informed consent prior to performing any study related procedures. Consent of a legally authorized guardian(s) is (are) required for legally minor participant as defined by local regulation. If the participant is legally minor, signed written consent shall be obtained from parent(s)/legal guardian and assent obtained from participants, if applicable.

You CAN'T join if...

  • The participant is <3 years of age.
  • The participant has known Pompe specific cardiac hypertrophy.
  • The participant is wheelchair dependent.
  • The participant is not able to ambulate 40 meters (approximately 130 feet) without stopping and without an assistive device.
  • The participant requires invasive-ventilation (non-invasive ventilation is allowed).
  • The participant is not able to successfully perform repeated forced vital capacity (FVC) measurements in upright position of greater than or equal to 30% predicted and less than or equal to 85% predicted.
  • The participant (and participant's legal guardian if participant is legally minor as defined by local regulation) is (are) not able to comply with the clinical protocol.
  • The participant has had previous treatment with alglucosidase alfa or any investigational therapy for Pompe disease.
  • The participant has prior or current use of immune tolerance induction therapy.
  • The participant, if female and of childbearing potential, has a positive pregnancy test (beta-human chorionic gonadotropin) at baseline.

The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.


  • Investigational Site Number 8400020
    Los Angeles California 90095 United States
  • Investigational Site Number 8400011
    Orange California 92868 United States
  • Investigational Site Number 8400017
    Stanford California 94305 United States


in progress, not accepting new patients
Start Date
Completion Date
Genzyme, a Sanofi Company
Phase 3 Pompe Disease Research Study
Study Type
At least 100 people participating
Last Updated