A Study to Evaluate AAV9 Neutralizing Antibody Seroconversion in Household Contacts.

A Low-Interventional Study Of AAV9 Neutralizing Antibody Seroconversion in Household Contacts of Participants Within the C3391003 Clinical Trial

This study will include male and female participants who live or work in the same household as a patient in one of the fordadistrogene movaparvovec interventional studies. Up to 5 participants from the same household may be enrolled. The objective is to estimate the likelihood of NAb seroconversion to AAV9 in household contacts of a patient in one of the interventional studies who is treated with fordadistrogene movaparvovec gene therapy.

Study Overview

• Status: Terminated
• Conditions: Household Contacts
• Intervention / Treatment: Other: Blood Draw

Detailed Description

This single center study will include approximately 50 to 250 participants and is designed to estimate the likelihood of NAb seroconversion to AAV9 because of exposure to shed viral vector material released by a DMD patient treated with fordadistrogene movaparvovec in an interventional study. Eligible participants will undergo a blood draw provided by a Home Health Care Vendor at three home visits.

The total duration of participation in this study is about 4 months, including up to 48 days for the screening/baseline period and about 56 days after the DMD patient of the same household is dosed with the investigational gene therapy in the interventional study.

To maintain the blind in the blinded interventional studies, all C3391007 study participants and investigators as well as the sponsor will remain blinded to the Cohort assignment of the interventional study patient until the interventional study becomes unblinded.

• Study Type: Observational
• Enrollment (Actual): 8

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21205
      • Kennedy Krieger Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 1 second and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

This single center study will include approximately 50 to 250 participants who live or work in the same household as a DMD patient in one of the fordadistrogene movaparvovec interventional studies. Up to 5 participants from the same household may be enrolled.

Description

Inclusion Criteria:

• Males or females who weigh at least 9 kg.
• Anticipated to be living or working in the same household as a patient in one of the fordadistrogene movaparvovec interventional studies for at least 4 months.
• Anticipated to have > 10 hours of contact per week and expected to have direct contact with the interventional study patient.
• The interventional patient is dosed in the interventional study.

Exclusion Criteria:

• Prior treatment with gene therapy utilizing AAV vectors of any serotype.

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
All participants; Household contacts of a DMD patient in an interventional study of fordadistrogene movaparvovec.	Other: Blood Draw; Blood Samples for NAb and ADA to AAV9

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants (Previously Seronegative for Neutralizing Antibodies [NAbs] to AAV9) Who Developed NAb to AAV9 at Day 28 After the Interventional Study Patient Was Dosed	Development of NAb to AAV9 was defined by an increase of >=6-fold above Baseline titer in participants with a detectable, but negative test (ie, titer >=1 and <4) for NAb to AAV9 at Baseline. If there was an undetectable titer at Baseline (ie, titer <1), then development of NAb to AAV9 was defined by a NAb to AAV9 titer >=6.	Day 28 after the interventional study participant was dosed
Number of Participants (Previously Seronegative for NAb to AAV9) Who Developed NAb to AAV9 at Day 56 After the Interventional Study Patient Was Dosed	Development of NAb to AAV9 was defined by an increase of >=6-fold above Baseline titer in participants with a detectable, but negative test (ie, titer >=1 and <4) for NAb to AAV9 at Baseline. If there was an undetectable titer at Baseline (ie, titer <1), then development of NAb to AAV9 was defined by a NAb to AAV9 titer >=6.	Day 56 after the interventional study participant was dosed

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants (Previously Seronegative for Anti-Drug Antibody [ADA] to AAV9) Who Developed ADA to AAV9 at Day 28 After the Interventional Study Patient Was Dosed	Development of ADA to AAV9 was defined by a titer ≥300 in participants with a negative test (ie, titer <50) for ADA to AAV9 at Baseline.	Day 28 after the interventional study participant was dosed
Number of Participants (Previously Seronegative for Anti-Drug Antibody [ADA] to AAV9) Who Developed ADA to AAV9 at Day 56 After the Interventional Study Patient Was Dosed	Development of ADA to AAV9 was defined by a titer ≥300 in participants with a negative test (ie, titer <50) for ADA to AAV9 at Baseline.	Day 56 after the interventional study participant was dosed

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): August 17, 2022
• Primary Completion (Actual): February 27, 2024
• Study Completion (Actual): February 27, 2024

Study Registration Dates

• First Submitted: August 7, 2020
• First Submitted That Met QC Criteria: September 2, 2020
• First Posted (Actual): September 10, 2020

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 5, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: seroconversion; viral shedding; DNA vector shedding
• Other Study ID Numbers: C3391007; ARISEN (Other Identifier: Alias Study Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No