A Long-Term Follow-Up Study of Haemophilia B Patients Who Have Undergone Gene Therapy

Brief Title

A Long-Term Follow-Up Study of Haemophilia B Patients Who Have Undergone Gene Therapy

Official Title

An Open-Label, Multicentre, Long-Term Follow-Up Study to Investigate the Safety and Durability of Response Following Dosing of a Novel Adeno-Associated Viral Vector (FLT180a) in Patients With Haemophilia B

Brief Summary

Severe haemophilia B (HB) is a bleeding disorder where a protein made by the body to help
make blood clot is either partly or completely missing. This protein is called a clotting
factor; with severe HB, levels of clotting Factor IX (nine; FIX) are very low and affected
individuals can suffer life threatening bleeding episodes. HB mainly affects boys and men
(approximately one in every 30,000 males). Current treatment for HB involves intravenous
infusions of FIX as regular treatment (prophylaxis) or 'on demand' treatment. On demand
treatment is highly effective at stopping bleeding but cannot fully reverse long-term damage
that follows after a bleed. Regular treatment can prevent bleeding; however it is invasive
for patients and also expensive.

This clinical study aims to investigate the long-term safety and durability of FIX activity
in participants who have been dosed with a new gene therapy product (FLT180a) in earlier
clinical studies. Following administration, FLT180a results in production of FIX in the
participants' liver cells which is then released into the blood stream. The aim is to have
the participants' own body produce levels of FIX that allow for clotting to occur as normal
as would be seen in a non-HB individual. This would remove the need for prophylaxis or on
demand treatment following just a single administration of FLT180a.

Up to 50 participants who have already been administered with FLT180a in the EU and US will
take part in this study. Participants will be followed up in this trial until they have
reached 15 years after being dosed. Participants will undergo procedures including physical
examinations, join assessments, blood tests and liver ultrasounds. Participants will also
need to complete a diary to document occurrence of bleeding episodes and record the amount of
Factor IX concentrate they receive. Patient reports outcomes including measures of Quality of
Life, disability and physical activity will also be collected.

Study Phase

Phase 1/Phase 2

Study Type

Interventional

Primary Outcome

Primary Safety Measurement

Secondary Outcome

 Secondary Safety Measurement

Condition

Hemophilia B

Intervention

FLT180a

Study Arms / Comparison Groups

 FLT180a

Description:  Participants who have received gene therapy vector (FLT180a)

Publications

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Information

Recruitment Status

Biological

Estimated Enrollment

Start Date

July 10, 2018

Completion Date

December 31, 2035

Primary Completion Date

December 31, 2035

Eligibility Criteria

        Inclusion Criteria:

          -  Patients who have previously received FLT180a within a clinical study.

          -  Able to give full informed consent and able to comply with all requirements of the
             study including long-term follow-up for the time frame the study requires.

          -  Willing to practice barrier contraception until at least three consecutive semen
             samples after vector administration are negative for vector sequences.

        Exclusion Criteria:

        N/A

Gender

Male

Ages

18 Years - N/A

Accepts Healthy Volunteers

No

Contacts

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Location Countries

United Kingdom

Location Countries

United Kingdom

Administrative Informations

NCT ID

NCT03641703

Organization ID

FLT180a-04

Responsible Party

Sponsor

Study Sponsor

Freeline Therapeutics

Study Sponsor

, ,

Verification Date

January 2020