Currently ongoing clinical trials
Hemophilia B (AMT-060)
The AMT-060 study is an ongoing Phase I/II, open-label, multi-center study including 10 patients with documented severe or moderately-severe hemophilia B. Patients had FIX levels less than 1-2% and required chronic infusions of prophylactic or on-demand Factor IX therapy at the time of enrollment. Each patient is receiving a one-time, 30-minute, intravenous administration of AMT-060, consisting of an AAV5 vector carrying a therapeutic human Factor IX, without the use of immunosuppression therapy. The study includes two dose cohorts of five patients each, with the first cohort receiving 5x1012 gc/kg and the second cohort receiving 2x1013 gc/kg. uniQure will follow all 10 patients in the study for a period of five years to further assess long-term safety and durability.
At the American Society of Hematology (ASH) Annual Meeting in December 2016, we presented up to 12 months of follow-up for our first cohort and up to 6 months of follow-up for our second dose (view press release).
The data from this ongoing study demonstrate clinically significant and sustained increases in FIX activity, substantial reductions in FIX replacement usage and a near cessation of spontaneous bleeding episodes.
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. This includes up to 31 weeks of follow-up.
All five patients in the low-dose cohort, who were previously managed by 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.
At both doses evaluated, AMT-060 appears to be safe and well-tolerated with no loss of FIX activity, no activation of T-cell response and no development of inhibitors for any of the 10 patients in the study. None of the patients treated have lost FIX activity for up to one year post administration. To date, our insect-cell manufactured AAV5 gene therapies have been administered to 22 patients across three clinical studies without any evidence of AAV5 capsid specific cellular immune responses or long-term safety complications.
Three out of the total of 10 patients experienced mild, asymptomatic elevations of alanine aminotransferase (ALT) and received a tapering course of steroids per protocol. These temporary elevations were not associated with any loss of FIX activity or T-cell response. They do not appear related to a capsid-specific immune response, and we suspect that they may be due to cell stress or external factors rather than immune activation.
AMT-060 continues to demonstrate a very low screening failure rate, with all patients screened in the study testing negative for pre-existing neutralizing antibodies against the AAV-vector uniQure is using in the trial. This collective data set suggests that a large proportion of the hemophilia patient population may be eligible for treatment with AMT-060.
The safety and clinical efficacy profile observed in this study, together with the higher FIX expression levels, support the selection of the 2x1013 gc/kg dose for a pivotal registration trial, pending discussions with regulators. In January 2017, AMT-060 received Breakthrough Therapy designation from the U.S. Food and Drug Administration in January 2017 based on results from this ongoing, dose-ranging study (view press release).
For more information on uniQure’s ongoing clinical trials please contact us at MedInfo@uniqure.com