Catalyst Biosciences Announces Preclinical Proof-of-Concept Data of Gene Therapy Candidate

Catalyst Biosciences (NASAQ:CBIO) has announced preclinical proof-of-concept data of its gene therapy candidate, CB 2679d-GT Factor IX  gene therapy in hemophilia B mice.

As quoted in the press release:

The adeno-associated virus (AAV)-based CB 2679d Factor IX gene therapy candidate demonstrated superior results when compared with an AAV-encoded Padua vector in both reduction in bleeding times (four-fold reduction) and clotting activity (three-fold improvement). The data were presented in a poster at the 12^th Annual Congress of the European Association for Haemophilia and Allied Disorders (EAHAD) held Feb. 6-8, 2019 in Prague.

“These results are encouraging and demonstrate preclinical proof-of-concept for CB 2679d-GT, a gene therapy candidate encoding our engineered Factor IX as a potential new treatment for hemophilia B,” said Nassim Usman, Ph.D., chief executive officer of Catalyst. “The data indicate that CB 2679d-GT achieves a more rapid and robust hemostatic correction of bleeding in hemophilia B mice with a significantly improved clotting activity and four-fold reduction of bleeding time when compared with an AAV-encoding FIX-R338L Padua. We remain committed to advancing dalcinonacog alfa (DalcA – subcutaneous recombinant CB 2679d) into a Phase 2b study this quarter and believe that CB 2679d-GT could be an important pipeline product that may provide additional treatment options for patients during their lifetime of therapy.”

The 20-week preclinical study compared the activity of CB 2679d-GT with that of an AAV-encoding FIX-R338L Padua (FIX-Padua) in hemophilia B mice. Treatment with both CB 2679d-GT and FIX-Padua showed a reduced clotting time within the first week that remained stable up to the 20-week study endpoint. CB 2679d-GT demonstrated a statistically significant, three-fold improvement in clotting activity (p <0.04), compared with FIX-Padua. Furthermore, when evaluated at 20 weeks, there was a four-fold reduction in bleeding time after treatment with CB 2679d-GT compared to FIX-Padua at both the 5×10⁹ vg/mouse (p < 0.01) and the 1×10¹⁰ vg/mouse (p < 0.01) dose levels. These results suggest that CB 2679d-GT exhibits a superior hemostatic potency when compared with FIX-Padua.

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