uniQure is advancing a promising clinical program focused on hemophilia B, a severe orphan blood clotting disorder. Our gene therapy product candidate etranacogene dezaparvovec (AMT-061) consists of an AAV5 viral vector carrying a gene cassette with the Padua variant of Factor IX (FIX-Padua). uniQure has now completed the Phase III HOPE‑B pivotal study of etranacogene dezaparvovec for the treatment of patients with severe and moderately severe hemophilia B.
In late 2021, we announced positive 78-week data on all patients from the trial, the first clinical data from a Phase III gene therapy study in hemophilia B and, with 54 patients, the largest set of hemophilia B patients receiving a gene therapy investigational product to date. The HOPE‑B data not only achieved the pre-specified primary endpoint of non-inferiority in annualized bleeding rate following 12 months or more of stable FIX expression, but also the secondary endpoint of superiority in reduction of annualized bleeding, while continuing to demonstrate durability and stability in FIX levels and other benefits. Participants continued to demonstrate durable, sustained increases in Factor IX (FIX) activity at one year following achievement of steady state, with a mean FIX activity of 36.9 percent of normal.
AAV5-based gene therapies have been demonstrated to be safe and well-tolerated in a multitude of clinical trials, including five uniQure trials conducted in nearly 80 patients in hemophilia B and other indications. No patient treated in clinical trials with uniQure’s AAV5 gene therapies has experienced any confirmed cytotoxic T‑cell-mediated immune response to the capsid. Additionally, pre-clinical and clinical data show that AAV5-based gene therapies may be viable treatments in patients with pre-existing antibodies to AAV5, thereby potentially increasing patient eligibility for treatment compared to other gene therapy product candidates.
Etranacogene dezaparvovec consists of an AAV5 viral vector carrying a gene cassette with the patent-protected Padua variant of Factor IX (FIX-Padua). uniQure holds multiple issued patents in the United States and Canada broadly, with patent pending in the EU, covering methods of treating bleeding disorders, including hemophilia B, using AAV gene therapy with the FIX-Padua variant.
Etranacogene dezaparvovec has been granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration (FDA) and access to the Priority Medicines (PRIME) regulatory initiative by the European Medicines Agency.
In May 2022 we announced that the FDA has accepted for priority review the Biologics License Application (BLA) submitted for etranacogene dezaparvovec. Priority review of a BLA is reserved for medicines that, if approved, would be potentially significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions when compared to standard applications. Previously, the European Medicines Agency (EMA) accepted the Marketing Authorization Application (MAA) for etranacogene dezaparvovec under its accelerated assessment procedure.
We believe that etranacogene dezaparvovec has the potential to be the first- and best-in-class gene therapy in hemophilia B, providing durable, functionally curative benefits to nearly all patients with hemophilia B. These factors, along with our commercial-scale manufacturing capabilities, differentiate etranacogene dezaparvovec from other hemophilia gene therapies in development.
uniQure has entered into a licensing agreement providing CSL Behring exclusive global rights to etranacogene dezaparvovec. Under the terms of the agreement, uniQure received a $450 million cash payment and will be eligible to receive up to $1.6 billion in payments based on regulatory and commercial milestones. uniQure will also be eligible to receive tiered double-digit royalties in a range of up to a low-twenties percent of on net sales of products arising from the collaboration based on sales thresholds.
uniQure is responsible for the completion of the HOPE‑B pivotal study, manufacturing process validation, and the commercial manufacturing supply of etranacogene dezaparvovec until such time that these capabilities are transferred to CSL Behring. Clinical development and regulatory activities performed by uniQure under the agreement will be reimbursed by CSL Behring. CSL Behring will be responsible for regulatory submissions and commercialization of etranacogene dezaparvovec.
The collaboration combines uniQure’s differentiated gene therapy candidate in hemophilia B and CSL Behring’s strong global reach and commercial infrastructure in hematology to accelerate access of etranacogene dezaparvovec to hemophilia B patients around the world.