UniQure’s gene therapy increases clotting in some hemophilia B patients

The company said all five patients in the low-dose cohort had Factor IX (FIX) phenotypic features of severe or moderately-severe hemophilia including documented FIX levels less than 1% to 2% and required chronic treatment with prophylactic recombinant FIX (rFIX) therapy during the time of enrollment.

The first two patients have completed at least 20 and 12 weeks of follow up and showed FIX expression levels of 5.5% and 4.5%, respectively.

Three additional subjects had been dosed but did not achieve the full 12 weeks of follow up. Two of the three, though, met a secondary endpoint of discontinuing prophylactic rFIX depending on their FIX expression levels.

UniQure CEO Dan Soland said: "These preliminary topline results support our hypothesis that AAV5/FIX can deliver clinically meaningful expression levels of FIX for patients with hemophilia B."

The company has to date administered its AAV5-based gene therapies to 13 adult patients across two clinical trials in two different disease states, and through direct central nervous system administration in four children in a third study.

UniQure plans to present the complete analysis of the data at a scientific conference in the second quarter of this year.

The company expects to start enrollment in the high-dose cohort this quarter after securing approval from the data monitoring committee.

AMT-060 features a codon-optimized wild type FIX gene and the LP1 liver promoter together with the AAV5 viral vector, manufactured using uniQure’s insect cell based manufacturing technology.

It is administered, without immunosuppressant therapy, via the peripheral vein in one treatment session for about half an hour.