uniQure Updates Progress on Gene Therapy for Hemophilia B

On May 10, uniQure published updated data on its gene therapy trial to potentially cure hemophilia B (factor IX deficiency). Three patients with severe hemophilia B are in the Phase IIb clinical trial. Six months after receiving a single dose of AMT-061, the patients have all had significant increases in their factor IX levels.

The gene therapy developed by uniQure is currently called AMT-061. It uses type 5 of the adeno-associated virus (AAV5) to deliver the Padua variant of the factor IX gene to the patient’s liver cells. The Padua variant is a form of the factor IX gene that can produce highly active amounts of factor protein. The three patients in the study all had low levels of antibodies to AAV5 before getting the gene therapy. While some gene therapy trials have excluded patients with antibodies to AAV, the uniQure trial allows them to enroll. This is important, as most people have antibodies to at least some types of AAV.

Before getting the gene therapy, the three patients all had factor IX activity of less than 1 percent. After receiving AMT-061, their factor activity levels increased to 51 percent for the first patient, to 33 percent for the second, and to 57 percent for the third. There have been no reports of serious side effects, unwanted blood clots, or inhibitors forming to factor IX.

In announcing their progress, Robert Gut, M.D., Ph.D., Chief Medical Officer of uniQure, stated, “Importantly, results across all patients in this study, even those that previously screen-failed other gene therapy studies, show no loss of FIX activity, no bleeding events and no need for infusions of FIX replacement therapy through six months after administration. Further, AMT-061 continues to be safe and well tolerated, with no patients requiring immunosuppression related to the therapy.”

The three patients in the Phase IIb trial will be followed for a year to check their factor IX levels, bleeding rates, and if they need to infuse factor. They’ll continue to be monitored for five years to make sure the gene therapy is safe. A Phase III clinical trial is currently enrolling 50 adult moderate and severe hemophilia B patients. Talk to your HTC hematologist or visit https://www.hopebtrial.com/ for more information.