immune tolerance induction study

Conditions: Pompe Disease; Glycogen Storage Disease Type II (GSD-II); Glycogenesis 2 Acid Maltase Deficiency

Summary: an exploratory, open-labeled study of participants with pompe disease, who had previously received myozyme® (alglucosidase alfa) treatment, to evaluate the efficacy, safety and clinical benefit of 2 immune tolerance induction (iti) regimens in combination with myozyme®. eligible participants who were then receiving myozyme® therapy were enrolled into the study, and were followed for a minimum of 18 months on-study (a 6-month iti treatment module and a 12-month follow-up module on myozyme® alone). eligible participants were followed for a minimum of 18 months on treatment or, if a participant was \<6 months of age at the time of enrollment, until the participant was 2 years of age. both cross-reacting immunologic material (crim)-negative and crim-positive participants were eligible for regimen a depending if they met the required criteria. regimen b, however, was limited to crim-negative participants.


Eligibility criteria:
inclusion criteria: * the participant (and/or participant's legal guardian if participant was \< 18 years) provided written informed consent prior to any study-related procedures that were performed. * the participants had a confirmed diagnosis of pompe disease defined as a documented acid α-glucosidase (gaa) enzyme deficiency from any tissue source or 2 gaa gene mutations. * the participant (and/or legal guardian) had ability to comply with clinical protocol. * if the participant was crim-positive, he/she had received at least 6 consecutive months of myozyme® infusions (20 mg/kg qow). * if the participant was crim-negative, he/she had received at least 1 myozyme® infusion prior to enrollment. * regimen a only: the participants exhibits clinical decline; the participant had persistent high anti-recombinant human acid α-glucosidase (anti-rhgaa) antibody titers and/or tested positive for antibodies that inhibit enzymatic activity and/or uptake of myozyme®; * regimen b only: the participant was crim-negative and the participant did not exhibit clinical decline; or all of the following: the participant was crim-negative and the participant exhibited clinical decline and the participant did not exhibit high anti-rhgaa antibody titers and had not tested positive for antibodies that inhibit enzymatic activity and/or uptake of myozyme®. exclusion criteria: * the participant had a clinical condition unrelated to pompe disease that would interfere with program assessments. * the participant was at risk of reactivation or was a carrier of hepatitis b or hepatitis c. * the participant was at risk of reactivation or had positive serology suggestive of active infection for cytomegalovirus, herpes simplex, jc virus, parvovirus or epstein barr virus. * the participant was at risk of reactivation of tuberculosis or had regular contact with individuals who were being actively treated for tuberculosis. * the participant had low serum albumin. * the participant had a major congenital abnormality. * the participant had used any investigational product (other than alglucosidase alfa) within 30 days prior to study enrollment. * the participant was pregnant or lactating. * the participant has had or was required to have any live vaccination within one month prior to enrollment.