Trial Outcomes & Findings for Phase 1/2 Dose Confirmation Study of FLT180a in Hemophilia B (NCT NCT05164471)
NCT ID: NCT05164471
Last Updated: 2026-07-31
Results Overview
Recruitment status
TERMINATED
Study phase
PHASE1/PHASE2
Target enrollment
6 participants
Primary outcome timeframe
Dosing through last study visit (average of 48 weeks)
Results posted on
2026-07-31
Participant Flow
This was a multicenter study with 6 study sites in USA and UK. A total of 7 participants were screened in the trial, of which, 6 participants were treated.
All participants came from the FLT-01 lead-in study (ECLIPSE), from which there was at least 6 months of data collected in a prospective manner detailing bleeding events and FIX consumption.
Participant milestones
| Measure |
FLT180a
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Overall Study
STARTED
|
6
|
|
Overall Study
COMPLETED
|
6
|
|
Overall Study
NOT COMPLETED
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Phase 1/2 Dose Confirmation Study of FLT180a in Hemophilia B
Baseline characteristics by cohort
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Age, Continuous
|
29.0 Years
STANDARD_DEVIATION 11.66 • n=9 Participants
|
|
Sex: Female, Male
Female
|
0 Participants
n=9 Participants
|
|
Sex: Female, Male
Male
|
6 Participants
n=9 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
White
|
5 Participants
n=9 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=9 Participants
|
|
Region of Enrollment
United States
|
3 Participants
n=9 Participants
|
|
Region of Enrollment
United Kingdom
|
3 Participants
n=9 Participants
|
PRIMARY outcome
Timeframe: Dosing through last study visit (average of 48 weeks)Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Number of Participants With Adverse Events
Number of Participants With any AE
|
6 participants
|
|
Number of Participants With Adverse Events
Any TEAE
|
6 participants
|
SECONDARY outcome
Timeframe: Last study visit (average of 48 weeks)One-Stage aPTT \& Chromogenic Assay (central lab)
Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Number of Participants With FIX Activity Levels >=5% and >= 10%
Number of participants with FIX activity levels >=10% at last visit
|
3 Participants
|
|
Number of Participants With FIX Activity Levels >=5% and >= 10%
Number of participants with FIX activity levels >=5% at last visit
|
5 Participants
|
SECONDARY outcome
Timeframe: Dosing through last study visit (average of 48 weeks)Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Number of Participants With FIX Inhibitor at Any Time Point
|
0 Participants
|
SECONDARY outcome
Timeframe: Dosing through last study visit (average of 48 weeks)Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Number Patients With Bleeding Episode
Number of patients with any spontaneous bleeding event
|
3 participants
|
|
Number Patients With Bleeding Episode
Number of patients with any spontaneous moderate/severe bleeding event
|
2 participants
|
SECONDARY outcome
Timeframe: Dosing through last study visit (average of 48 weeks)Time of first \<LLD (lower limit detection) value
Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Mean Time to Cleared Viral Shedding
Plasma
|
3.67 Weeks
Interval 3.0 to 6.0
|
|
Mean Time to Cleared Viral Shedding
Semen
|
3.34 Weeks
Interval 2.0 to 6.0
|
SECONDARY outcome
Timeframe: Dosing through last study visit (either Week 26 or W52)Central lab
Outcome measures
| Measure |
FLT180a
n=6 Participants
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Number of Participants With Abnormal Serum Alpha-fetoprotein Levels
|
0 participants
|
Adverse Events
FLT180a
Serious events: 0 serious events
Other events: 6 other events
Deaths: 6 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
FLT180a
n=6 participants at risk
A single dose of FLT180a will be administered. All 6 patients received 7.7 x 10e11 vg/kg.
|
|---|---|
|
Psychiatric disorders
Anxiety
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Psychiatric disorders
Insomnia
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Psychiatric disorders
Irritability
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Psychiatric disorders
Mood swings
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Psychiatric disorders
Poor quality sleep
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Respiratory, thoracic and mediastinal disorders
Dyspnoea
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Respiratory, thoracic and mediastinal disorders
Oropharyngeal pain
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Skin and subcutaneous tissue disorders
Acne
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Skin and subcutaneous tissue disorders
Dermatitis acneiform
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Skin and subcutaneous tissue disorders
Rash
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Skin and subcutaneous tissue disorders
Rash macular
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Vascular disorders
Hot flush
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
Joint range of motion decreased
|
16.7%
1/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
Joint stiffness
|
16.7%
1/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
Nack pain
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
Pain in extremity
|
33.3%
2/6 • Number of events 4 • From dosing through study completion (an average of 48 weeks)
|
|
Nervous system disorders
Dizziness
|
16.7%
1/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Nervous system disorders
Dysgeusia
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Nervous system disorders
Headache
|
50.0%
3/6 • Number of events 11 • From dosing through study completion (an average of 48 weeks)
|
|
Nervous system disorders
Paraesthesia
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Cardiac disorders
palpitations
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Congenital, familial and genetic disorders
Factor IX deficiency
|
33.3%
2/6 • From dosing through study completion (an average of 48 weeks)
|
|
Eye disorders
Eye pain
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Eye disorders
Vision blurred
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Gastrointestinal disorders
Abdominal discomfort
|
33.3%
2/6 • Number of events 5 • From dosing through study completion (an average of 48 weeks)
|
|
Gastrointestinal disorders
Constipation
|
16.7%
1/6 • Number of events 6 • From dosing through study completion (an average of 48 weeks)
|
|
Gastrointestinal disorders
Diarrhea
|
33.3%
2/6 • Number of events 3 • From dosing through study completion (an average of 48 weeks)
|
|
Gastrointestinal disorders
nausea
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Gastrointestinal disorders
Vomiting
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
Chest discomfort
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
Fatigue
|
33.3%
2/6 • Number of events 4 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
Feeling hot
|
16.7%
1/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
Body temperature change
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
pain
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
General disorders
Pyrexia
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Infections and infestations
COVID-19
|
50.0%
3/6 • Number of events 3 • From dosing through study completion (an average of 48 weeks)
|
|
Infections and infestations
influenza
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Infections and infestations
Nasopharyngitis
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Infections and infestations
Oral candidiasis
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Infections and infestations
Urinary tract infection
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Injury, poisoning and procedural complications
Accidental overdose
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Injury, poisoning and procedural complications
Foot fracture
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Injury, poisoning and procedural complications
Road traffic accident
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Injury, poisoning and procedural complications
Skin laceration
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Alanine aminotransferase increase
|
83.3%
5/6 • Number of events 9 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Aspartate aminotransferase increased
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Cytomegalovirus test positive
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Heart rate increased
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
SARS-CoV-2 test positive
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Serum ferritin decreased
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Investigations
Weight increased
|
16.7%
1/6 • Number of events 1 • From dosing through study completion (an average of 48 weeks)
|
|
Metabolism and nutrition disorders
Increased appetite
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
Arthralgia
|
50.0%
3/6 • Number of events 10 • From dosing through study completion (an average of 48 weeks)
|
|
Musculoskeletal and connective tissue disorders
back pain
|
33.3%
2/6 • Number of events 2 • From dosing through study completion (an average of 48 weeks)
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place