New Medicines

Haemophilia B


New molecular entity
Freeline Therapeutics
Freeline Therapeutics

Development and Regulatory status

Phase II Clinical Trials
Phase II Clinical Trials
Phase II Clinical Trials
Oct 20Freeline has an agreement with Thermo Fisher Scientific securing dedicated production capacity and resources for the manufacture of FLT180a from 2021 to 2027, to support the planned pivotal trial and potential commercialisation [4].
Oct 20Freeline Therapeutics plans to conduct an End of PII Meeting with the FDA to align on a final dose and design for PIIb/III pivotal trial. It began enrolment of patients in the 6-month baseline run in study for the planned PIIb/III pivotal trial, with initiation expected mid-year 2021 [4].


A next generation, adeno-associated virus gene therapy consists of a single stranded, replication incompetent adenovirus vector, in which a codon optimised variant FIX transgene is encapsidated in a novel synthetic capsid (AAVS3).
Haemophilia B has a prevalence of around 1 in 30,000 live births (around 20% incidence of haemophilia A) and affected males have a deficiency of Factor IX clotting factor. Severe disease occurs with a factor IX level below 1% of the reference and accounts for about 50% of cases [1].
Haemophilia B
Intravenous infusion

Trial or other data

Oct 20Freeline announces that it has completed dosing in the PI/II adaptive dose finding B-AMAZE trial. It has dosed 10 patients across four dose cohorts, with all patients having completed 6-month follow-up and now enrolled in the ongoing long-term extension study. Reported data that suggest FLT180a is the only treatment that has demonstrated durable levels of FIX activity in the normal range, with no bleeds requiring supplemental FIX to date [4].
Apr 20Results from the PI/II B-AMAZE trial show FLT180a at 9.75x1011 vg/kg had FIX activity between 70-150%; which is the upper part of the normal range. Earlier results from two patients with haemophilia B, showed that FIX (Factor IX) activity was stable and consistent post steady state at 40 ± 5.5% over 66 weeks and 74 weeks post-administration, respectively. Both patients were relieved of spontaneous bleeding episodes following treatment, and the need for Factor IX supplementation was precluded [3].
Mar 20PI/II B-AMAZE trial is recruiting [2].
Dec 17PI/II B-AMAZE trial to evaluate the safety and effectiveness of FLT180a in patients with haemophilia B starts (FIX-GT; UCL/15/0552; NCT03369444). The first-in-human, open label, ascending single dose study intends to enrol 24 patients in the US, Italy and UK. UK study sites are Basingstoke Haemostasis and Thrombosis Centre, East Kent Hospitals, Guy´s and St Thomas´s NHS Foundation Trust (London), Royal Free Hospital (London), Newcastle Hospitals, Oxford University Hospital, University of Sheffield and University Hospital Southampton. Primary outcome is safety. The study is due to complete Jun 21 [2].