Phase 3 N=119 Treatment

A Study to Assess the Long-term Safety and Efficacy of ATB200/AT2221 in Adult Subjects With Late-Onset Pompe Disease (LOPD)

Pompe Disease (Late-onset)

Bottom Line

View on ClinicalTrials.gov: NCT04138277 ↗

Enrolled (actual)

119

Serious AEs

22.9%

Results posted

Jan 2026

Primary outcome: Primary: Incidence of Treatment-emergent Adverse Events (TEAEs), Treatment-emergent Serious Adverse Events (TESAEs), and TEAEs Leading to Discontinuation of Study Drug — 80; 37; 17; 10 Participants

Study Design & Population

Study type: Interventional
Phase: Phase 3
Interventions: AT2221 (Drug); ATB200 (Biological)
Age: Adult, Older Adult · 18+ yrs
Sex: All
Sponsor: Amicus Therapeutics
Primary completion: Dec 2024

Outcome Measures

Outcome	Result	p-value
PRIMARY Incidence of Treatment-emergent Adverse Events (TEAEs), Treatment-emergent Serious Adverse Events (TESAEs), and TEAEs Leading to Discontinuation of Study Drug	80; 37; 17; 10; 6; 2	—
SECONDARY Change From Baseline in 6-Minute Walk Distance (6MWD)	-33.3; -8.6	—
SECONDARY Change From Baseline in Sitting % Predicted Forced Vital Capacity (FVC)	-3.8; -0.5	—
SECONDARY Change From Baseline in Manual Muscle Testing (MMT) Lower Extremity Score	0.6; 0.4	—
SECONDARY Change From Baseline in the Total Score for Patient-reported Outcomes Measurement Information System (PROMIS®) - Physical Function	-2.7; -2.5	—
SECONDARY Change From Baseline in the Total Score for PROMIS® - Fatigue	1.5; 1.1	—
SECONDARY Change From Baseline in Gait, Stairs, Gower, Chair (GSGC) Test	0.5; 0.3	—
SECONDARY Change From Baseline in EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) Responses	27; 12; 4; 1; 0; 0	—
SECONDARY Change From Baseline in Overall Physical Well-being (Subject's Global Impression of Change [SGIC], Question 1)	0; 0; 0; 1; 12; 2	—
SECONDARY Change From Baseline in Physician's Global Impression of Change (PGIC) Overall Status	0; 0; 0; 1; 9; 3	—
SECONDARY Percent Change From Baseline in Creatine Kinase (U/L)	-17.8; -29.0	—
SECONDARY Percent Change From Baseline in Urine Hex4 (mmol/Mol Creatinine)	-16.7; -62.4	—
SECONDARY Proportion of Subjects With Positive Anti-drug Antibodies at Baseline and Week 208	63; 30; 34; 17	—

Summary

This is a multicenter, international open-label extension study of ATB200/AT2221 in adult subjects with late-onset Pompe disease (LOPD) who completed Study ATB200-03.

Eligibility Criteria

Inclusion Criteria

Subject must have completed Study ATB200-03.

Note: Subjects who were forced to withdraw from Study ATB200-03 for a logistical reason not related to the efficacy or safety of cipaglucosidase alfa/miglustat (eg, hospitalization for a car accident, COVID-19 pandemic, or emergency surgery) that resulted in several consecutive missed doses may have been eligible to participate in this study upon approval by the Amicus medical monitor.

Exclusion Criteria

Subject plans to receive gene therapy or participate in another interventional study for Pompe disease.
Subject, if female, is pregnant or breastfeeding.
Subject, whether male or female, is planning to conceive a child during the study.
Subject had a hypersensitivity to any of the excipients in cipaglucosidase alfa or miglustat, or had a medical condition or any other extenuating circumstance that may have, in the opinion of the investigator or medical monitor, posed an undue safety risk to the subject or may have compromised his/her ability to comply with or adversely impacted protocol requirements.

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT04138277). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.