Ongoing and planned clinical trials
uniQure plans to expeditiously advance AMT-061, which combines an AAV5 vector with the FIX-Padua mutant, into a pivotal Phase III study in 2018 for patients with severe and moderately severe hemophilia B.
We have achieved general agreement with the FDA and EMA on the proposed pivotal trial plan for AMT-061. The study is expected to be an open-label, single-dose, multi-center, multi-national trial investigating the efficacy and safety of AMT-061 administered to adult patients with severe or moderately severe hemophilia B. The primary objective of the trial is to evaluate AMT-061 for prevention of bleedings. Secondary objectives include additional efficacy and safety aspects. Patients will serve as their own control, with a baseline established during a six-month observational lead-in phase prior to treatment with AMT-061.
Concurrent with the start of the six-month lead-in phase of the pivotal study, a short dose-confirmation study is expected to begin in the third quarter of 2018. Three patients will receive a single intravenous (IV) dose of AMT-061 at 2x1013 gc/kg and will be evaluated for a period of approximately six weeks to assess FIX activity levels and confirm the dose. Each patient will continue to be followed longer term, and no lead-in phase is required for the dose confirmation study.
AMT-061 and AMT-060, the latter of which has been tested in 10 patients in our ongoing Phase I/II study, are identical gene therapies apart from two nucleotide substitutions in the coding sequence for FIX. The gene variant, referred to as FIX-Padua, has been reported to provide an approximate 8 to 9-fold increase in FIX activity compared to the wild-type FIX protein used in AMT-060. All other critical quality attributes of AMT-061 are expected to be comparable to those of AMT-060, as AMT-061 utilizes the same AAV5 capsid and proprietary insect cell-based manufacturing platform.
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.
In July 2017, the Company presented updated clinical data from our Phase I/II trial (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.
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.
All patients screened in the study tested negative for pre-existing neutralizing antibodies against the AAV5 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.
For more information on uniQure’s clinical trials please contact us at MedInfo@uniqure.com.