Results show a four-fold reduction in bleeding time for CB 2679d-GT and a three-fold improvement in clotting activity when compared with an AAV-encoding Padua vector

Data presented at the 12th Annual Congress of the European Association for Haemophilia and Allied Disorders (EAHAD)

SOUTH SAN FRANCISCO, CA, USA I February 06, 2019 I Catalyst Biosciences, Inc. (NASDAQ: CBIO), a clinical-stage biopharmaceutical company focused on developing novel medicines to address hematology indications presented preclinical proof-of-concept data of CB 2679d-GT Factor IX gene therapy in hemophilia B mice.  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 12th 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.

A copy of the poster can be accessed on the Events and Presentations section of the Catalyst website.

About Catalyst Biosciences
Catalyst is a clinical-stage biopharmaceutical company developing novel medicines to address hematology indications. Catalyst is focused on the field of hemostasis, including the subcutaneous prophylaxis of hemophilia and facilitating surgery in individuals with hemophilia. For more information, please visit www.catalystbiosciences.com.

SOURCE: Catalyst Biosciences