UniQure appears to be holding onto its lead in developing a gene therapy for hemophilia B, announcing Tuesday enrolment into a Phase 3 study of the experimental treatment could be completed by the end of this month.Already all 56 planned participants have entered the study. Seeing high levels of interest from patients and investigators, though, uniQure said it will over-enroll six additional patients before the end of September. Results from the trial, called HOPE-B and spanning 39 sites, could come as soon as March 2020, substantially before uniQure’s closest competitor Pfizer is expected to read out data from its Phase 3 study of a rival therapy.
Wall Street analysts think uniQure could be the first to develop a gene therapy for hemophilia B, a rare bleeding disorder caused by insufficient levels of a protein called Factor IX.
The biotech’s progress has reportedly attracted attention from pharma companies interested in gene therapy, and it has explored a potential sale, according to Bloomberg.
Enrolling the target 56 patients into HOPE-B took uniQure just over a year from initiating the study. With a competitive cushion and continued interest from patients, uniQure has the luxury of expanding the trial further.
“With the confirmation on trial enrollment completion, we believe this reinforces a key advantage that uniQure has, the potential of being the first AAV-based gene therapy for hemophilia B on the market,” wrote Elemer Piros, an equities analyst at Cantor Fitzgerald, in a Sept. 3 note to clients.
HOPE-B is designed to test uniQure’s therapy, called AMT-061 or etranacogene dezaparvovec, in patients with either severe or moderately severe hemophilia B.
After a six-month observational period to establish baseline measurements, study participants receive a one-time infusion of the drug. Factor IX activity, the primary endpoint of the study, is assessed 26 weeks following dosing.
In a Phase 1/2 study, treatment with AMT-061 led to increased Factor IX activity of up to 54% of normal. Data cited by uniQure shows that activity above 12% is associated with either substantial reduction or elimination of spontaneous bleeding as well as treatment with factor replacement therapy.
UniQure’s main competition is from Pfizer, which is developing a rival hemophilia B therapy it licensed from Spark Therapeutics. Its Phase 3 study began in July 2019, and is set to read out results in July 2021. Sangamo Therapeutics is also developing a gene editing approach to treating hemophilia B.
It’s a different story for the more common hemophilia A, where BioMarin Pharmaceutical holds a lead over Pfizer, Spark and Sangamo.