Pfizer’s Durveqtix (fidanacogene elaparvovec) has been recommended by the European Medicines Agency’s (EMA) human medicines committee to treat adults with severe and moderately severe haemophilia B.
The Committee for Medicinal Products for Human Use (CHMP) has specifically recommended that the one-time gene therapy be granted conditional marketing authorisation for use in patients who do not have both factor IX (FIX) inhibitors and detectable antibodies to variant adeno-associated virus serotype Rh74.
Affecting more than 38,000 people globally, haemophilia B is a rare inherited bleeding disorder resulting from missing or insufficient levels of clotting FIX.
The majority of therapies authorised for the condition require regular intravenous infusions of FIX replacement products to prevent or treat bleeding and the EMA has outlined that patients need new treatments that provide sustained bleed protection, reduce the frequency of infusions and improve their quality of life.
Pfizer’s Durveqtix is also administered as an intravenous infusion, but is designed to enable patients to produce FIX themselves.
The CHMP’s decision on the therapy was supported by positive results from an ongoing late-stage trial, which has been comparing annualised bleeding rate (ABR) in patients treated with Durveqtix against the period when they were receiving a routine FIX prophylaxis regimen, administered as part of standard care, in a lead-in study.
An ABR of 1.44 was observed for Durveqtix compared to 4.5 for prophylaxis treatment and 60% of patients remained without a bleeding event in the individual observation period, which ranged from two four years, compared to 29% of patients when they received routine prophylaxis treatments during the lead-in period.
Patients treated with Durveqtix will be followed up for 15 years, including six years in the trial and an additional nine years as part of a separate study to monitor the long-term efficacy and safety of the therapy.
The recommendation, which will now be reviewed by the European Commission, comes just over a month after fidanacogene elaparvovec was approved by the US Food and Drug Administration under the brand name Beqvez to treat certain adults with moderate-to-severe haemophilia B.
Adam Cuker, director, Penn Comprehensive and Hemophilia Thrombosis Program, said at the time of the April announcement: “A one-time treatment with [fidanacogene elaparvovec] has the potential to be transformative for appropriate patients by reducing both the medical and treatment burden over the long term.”