Trial Outcomes & Findings for A Study to Evaluate AAV9 Neutralizing Antibody Seroconversion in Household Contacts. (NCT NCT04543357)

NCT ID: NCT04543357

Last Updated: 2025-02-26

Results Overview

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.

Recruitment status

TERMINATED

Target enrollment

8 participants

Primary outcome timeframe

Day 56 after the interventional study participant was dosed

Results posted on

2025-02-26

Participant Flow

This was a low-interventional study to assess development of neutralizing Antibodies (NAbs) to adeno associated virus serotype 9 (AAV9) in household contacts of Duchenne Muscular Dystrophy (DMD) Patients Treated with fordadistrogene movaparvovec.

Participant milestones

Participant milestones
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
Overall Study
STARTED
8
Overall Study
COMPLETED
8
Overall Study
NOT COMPLETED
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
n=8 Participants
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
Age, Continuous
41.0 Years
STANDARD_DEVIATION 9.35 • n=99 Participants
Sex: Female, Male
Female
6 Participants
n=99 Participants
Sex: Female, Male
Male
2 Participants
n=99 Participants
Race/Ethnicity, Customized
Hispanic or Latino
1 Participants
n=99 Participants
Race/Ethnicity, Customized
Not Hispanic or Latino
7 Participants
n=99 Participants

PRIMARY outcome

Timeframe: Day 28 after the interventional study participant was dosed

Population: "Number of participants analyzed" signifies number of participants evaluable for the outcome measure: Participants with a NAb titer undetectable (ie, titer \<1) or detectable, but negative test (ie, titer \>=1 and \<4) at Baseline were included in the analysis.

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.

Outcome measures

Outcome measures
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
n=3 Participants
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
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
0 Participants

PRIMARY outcome

Timeframe: Day 56 after the interventional study participant was dosed

Population: "Number of participants analyzed" signifies number of participants evaluable for the outcome measure: Participants with a NAb titer undetectable (ie, titer \<1) or detectable, but negative test (ie, titer \>=1 and \<4) at Baseline were included in the analysis.

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.

Outcome measures

Outcome measures
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
n=3 Participants
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
Number of Participants (Previously Seronegative for NAb to AAV9) Who Developed NAb to AAV9 at Day 56 After the Interventional Study Patient Was Dosed
0 Participants

SECONDARY outcome

Timeframe: Day 28 after the interventional study participant was dosed

Population: "Number of participants analyzed" signifies number of participants evaluable for the outcome measure: Participants with an ADA titer negative at Baseline were included in the analysis.

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.

Outcome measures

Outcome measures
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
n=7 Participants
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
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
0 Participants

SECONDARY outcome

Timeframe: Day 56 after the interventional study participant was dosed

Population: "Number of participants analyzed" signifies number of participants evaluable for the outcome measure: Participants with an ADA titer negative at Baseline were included in the analysis.

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.

Outcome measures

Outcome measures
Measure
Participants With Potential Fordadistrogene Movaparvovec Exposure
n=7 Participants
People working or living in the same household of patients who were enrolled in an interventional study of fordadistrogene movaparvovec (including study C3391003 \[NCT04281485\] and C3391002 \[not listed on ClinicalTrials.gov\]) were enrolled.
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
0 Participants

Adverse Events

Participants With Potential Fordadistrogene Movaparvovec Exposure

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Pfizer ClinicalTrials.gov Call Center

Pfizer Inc.

Phone: 1-800-718-1021

Results disclosure agreements

  • Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
  • Publication restrictions are in place

Restriction type: OTHER