- After meetings with U.S. and European regulators, Dutch biotech uniQure N.V. on Thursday announced plans to move a revamped version of its hemophilia B gene therapy into a pivotal study next year, sending shares in the company sharply higher.
- The new therapy, known as AMT-061, is similar to uniQure's existing AMT-060 candidate, which has been tested in a Phase 1/2 study. UniQure is touting AMT-061 as more effective and more broadly applicable than the older candidate.
- Importantly, both the Food and the Drug Administration and the European Medicines Agency signed off on including AMT-061 under existing designations for AMT-060, clearly a regulatory pathway to accelerate work on AMT-061.
Perhaps in a nod to boost confidence in its reworked candidate, uniQure noted that AMT-061 and AMT-060 are identical in structure except for two nucleotide substitutions in the coding sequence for FIX. This gene variant, known as FIX-Padua, appears to be correlated to higher FIX activity than wild-type FIX protein, uniQure said.
"Our mission in hemophilia B has always been to develop the safest and most effective gene therapy with the broadest application to patients," said uniQure CEO Matthew Kapusta. "We believe AMT-061 moves us closer to this goal, as it has the potential to provide optimized clinical and tolerability benefits to nearly all severe and moderately severe patients with hemophilia B."
The pivotal study next year will be an open-label, single-dose trial to evaluate AMT-061 for prevention of bleeds in patients with severe or moderately severe hemophilia B. UniQure said it will measure a baseline during a six-month observational lead-in before treatment with AMT-061.
Importantly, uniQure also announced the acquisition of a patent family that covers the FIX-Padua variant and its use in gene therapies from Professor Paolo Simioni of the University of Padua in Italy.
Michael Yee, an equity analyst at Jefferies, sees uniQure's choice to switch from AMT-060 to AMT-061 as a positive one. Yet Yee did question the news in light of Italian drugmaker Chiesi stepping out of its partnership with uniQure on AMT-060 earlier this year.
"We note partner Chiesi returned this program to uniQure ... therefore, today's news is somewhat odd as it could mean Chiesi gave the program back knowing or not knowing that uniQure would use the F9-Padua variant," Yee wrote.
Under an agreement with the FDA, AMT-061 will be covered by AMT-060's Breakthrough Therapy designation and Investigational New Drug application. Similarly, an agreement with the EMA means that AMT-061 can retain AMT-060's PRIME designation.
One of uniQure's key potential competitors, Spark Therapeutics, also has a hemophilia B gene therapy in Phase 1/2. SPK-9001, as it is known, is in development in collaboration with Pfizer Inc., and delivers the FIX-Padua variant with an AAV vector. Interim data from a Phase 1/2 study showed a 99% reduction in annualized infusion rate and a 96% reduction in annualized bleeding rate. Spark plans a pivotal study in 2018.
While Yee acknowledges that uniQure now could be more of a competitor for Spark, he sees uniQure's news as "incremental," leaving Jefferies' positive view of Spark unchanged.