- UniQure appears to be holding onto its lead in developing a gene therapy for hemophilia B, announcing Tuesday enrollment 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.