uniQure’s gene therapy for severe hemophilia B gets PRIME designation in Europe

This designation is based on results from the ongoing, dose-ranging Phase 1-2 study that show a near cessation of spontaneous bleeding in patients with severe disease at up to 12 months follow-up, clinically significant and sustained increases in Factor IX (FIX) and substantial reductions in FIX replacement usage.

Matthew Kapusta, chief executive officer of uniQure said: "We are very pleased to have AMT-060 for hemophilia B accepted into the PRIME program.

"Similar to the Breakthrough Therapy designation that AMT-060 received from the U.S. Food and Drug Administration earlier this year, we look forward to this enhanced collaboration with the EMA to advance the clinical development of this potentially transformative therapy for hemophilia B patients."

Phase 1-2 Data

Updated clinical data from the ongoing, two-cohort Phase 1-2 trial of AMT-060 were presented last December at the 58th American Society of Hematology (ASH) Annual Meeting.  The data included up to 52 weeks of follow-up from the low-dose cohort and up to 31 weeks of follow-up from the second dose cohort.

Data from the second-dose cohort show a dose response with substantial improvement in disease state in all five patients, including the discontinuation of precautionary FIX infusions in all four patients that previously required chronic replacement therapy. 

To date, only one spontaneous bleed was reported after discontinuation of prophylactic FIX replacement therapy.

All five patients in the low-dose cohort, whose bleedings were previously uncontrolled despite being managed with prophylactic therapy, continue to maintain robust, constant and clinically meaningful levels of FIX activity for up to 52 weeks post treatment, with a complete cessation of spontaneous bleedings in the last 14 weeks of observation.

AMT-060 continues to be well-tolerated, and there have been no severe adverse events. Three out of the total of 10 patients (two in the second-dose cohort and one previously reported from the low-dose cohort) experienced mild, asymptomatic elevations of alanine aminotransferase (ALT) and received a tapering course of corticosteroids per protocol.

Importantly, the temporary elevations in ALT were not associated with any loss of endogenous FIX activity or T-cell response.

No patients across either cohort have developed inhibitory antibodies against FIX, or demonstrated sustained AAV5 capsid-specific T-cell activation.