Freeline Therapeutics has dosed the first subject in the Phase I/II B-LIEVE clinical trial of its therapy FLT180a to treat haemophilia B.
FLT180a is a next-generation adeno-associated virus (AAV) gene therapy to treat haemophilia B, a genetic bleeding disorder that is caused by the clotting factor IX protein deficiency.
It uses the adeno-associated virus vector capsid (AAVS3) for providing the function gene of a variant of human factor IX and to restore the formation of normal blood clots.
The study is a dose-confirmation trial of FLT180a, which is produced at a commercial scale.
In this trial, 7.7e11vg/kg of initial dose and a short course of prophylactic immune management will be used to normalise the FIX levels.
Freeline stated that the dose was selected depending on the data obtained from B-AMAZE, as well as many modelling approaches.
The B-LIEVE study is expected to finalise a dose for the planned Phase III pivotal trial, which is designed to consistently normalise FIX levels in haemophilia B patients.
Freeline Therapeutics chief medical officer Pamela Foulds said: “We are optimistic that the combination of a low dose (7.7e11vg/kg) of our high-expression AAVS3 capsid with a short prophylactic immune management regimen can get and keep haemophilia B patients in the normal range of Factor IX expression.
“This is a meaningful step towards realising the potential of FLT180a to provide a functional cure through sustained, normalised FIX activity.”
The preliminary safety and biomarker data from the B-LIEVE trial’s first dose cohort is expected in the first half of this year.
Freeline expects to complete the additional patients dosing in the first cohort or dosing of the second cohort if necessary, by the end of the third quarter of this year.
Furthermore, the company expects to begin the start-up activities for the Phase III trial in the first half of next year.