A clinical study to learn about the effects of a virus that transfers the gene for human coagulation factor IX in adults with moderate/severe to severe inherited coagulations defects in the long term

A Long-Term Follow-up Study to Evaluate the Safety, Tolerability, and Efficacy of Adeno-Associated Virus (AAV) rh10-Mediated Gene Transfer of Human Factor IX in Adults With Moderate/Severe to Severe Hemophilia B

Status

Not yet recruiting

Phases

Phase 1Phase 2

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2016-003430-25-GB

Enrollment

Registered

2017-03-13

Start date

2017-05-18

Completion date

Unknown

Last updated

2019-06-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Moderate/severe to severe hemophilia B MedDRA version: 20.0 Level: LLT Classification code 10060614 Term: Hemophilia B (Factor IX) System Organ Class: 100000004850

Interventions

Product Code: DTX101 Pharmaceutical Form: Concentrate for solution for infusion INN or Proposed INN: Not yet assigned Other descriptive name: DTX101

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: 1. Willing and able to provide written informed consent 2. Completed the Cohort 1/Week 52 or Cohort 2/week 44 visit in Study 101HEMB01 3. Willing to stop prophylactic treatment with recombinant FIX at specified time points during the study if medically acceptable 4. Willing, able, and committed to comply with scheduled study site visits, study procedures, and requirements Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 5 F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range 1

Exclusion criteria

Exclusion criteria: 1. Planned or current participation in another interventional clinical study that may confound the safety or efficacy evaluation of DTX101 during the duration of this study 2. Any clinically significant medical condition that, in the opinion of the investigator, would pose a risk to subject safety or would impede the study

Design outcomes

Primary

Measure	Time frame
Main Objective: 1. To determine the long-term safety and efficacy of DTX101 following a single IV infusion in adults with moderate/severe to severe hemophilia B; Secondary Objective: 1. To evaluate the long-term kinetics, duration, and magnitude of plasma FIX activity, by dose, after a single IV infusion of DTX101 in adults with hemophilia B 2. To assess the long-term impact of DTX101 on the number of bleeding episodes that require FIX replacement therapy 3. To assess the long-term impact of DTX101 on the frequency of FIX replacement therapy use during the study 4. To assess the long-term immune response to FIX after IV administration of DTX101 ; Primary end point(s): 1. The incidence of AEs and SAEs 2. The change from baseline (predose on Day 0 for Study 101HEMB01) in FIX activity at Week 208/216 (±14 days) as determined by the aPTT clot-based assay ; Timepoint(s) of evaluation of this end point: 1. From the time the subject signs the ICF until their exit from the study 2. Week 208/216 (±14 days)	—

Measure

Time frame

Main Objective: 1. To determine the long-term safety and efficacy of DTX101 following a single IV infusion in adults with moderate/severe to severe hemophilia B; Secondary Objective: 1. To evaluate the long-term kinetics, duration, and magnitude of plasma FIX activity, by dose, after a single IV infusion of DTX101 in adults with hemophilia B 2. To assess the long-term impact of DTX101 on the number of bleeding episodes that require FIX replacement therapy 3. To assess the long-term impact of DTX101 on the frequency of FIX replacement therapy use during the study 4. To assess the long-term immune response to FIX after IV administration of DTX101 ; Primary end point(s): 1. The incidence of AEs and SAEs 2. The change from baseline (predose on Day 0 for Study 101HEMB01) in FIX activity at Week 208/216 (±14 days) as determined by the aPTT clot-based assay ; Timepoint(s) of evaluation of this end point: 1. From the time the subject signs the ICF until their exit from the study 2. Week 208/216 (±14 days)

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Secondary

Measure	Time frame
Secondary end point(s): 1. The time course of FIX activity, as determined by aPTT 2. The annualized bleeding rate through Week 208/216 (±14 days) 3. The annualized and average weekly use of FIX replacement therapy through Week 208/216 (±14 days) 4. Development of FIX inhibitor ; Timepoint(s) of evaluation of this end point: 1. Day 0, Weeks 26-156, Unscheduled visit, Week 208/216 (±14 days) 2. Through Week 208/216 (±14 days) 3. Through Week 208/216 (±14 days) 4. Day 0, Weeks 26-156, Unscheduled visit, Week 208/216 (±14 days)	—

Measure

Time frame

Secondary end point(s): 1. The time course of FIX activity, as determined by aPTT 2. The annualized bleeding rate through Week 208/216 (±14 days) 3. The annualized and average weekly use of FIX replacement therapy through Week 208/216 (±14 days) 4. Development of FIX inhibitor ; Timepoint(s) of evaluation of this end point: 1. Day 0, Weeks 26-156, Unscheduled visit, Week 208/216 (±14 days) 2. Through Week 208/216 (±14 days) 3. Through Week 208/216 (±14 days) 4. Day 0, Weeks 26-156, Unscheduled visit, Week 208/216 (±14 days)

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Countries

United Kingdom, United States

Contacts

Public ContactClinical Development

Ultragenyx Pharmaceutical, Inc.

apoma@ultragenyx.com+1617 714 0704

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026