Spark Therapeutics recently announced updated preliminary data from an ongoing Phase 1/2 clinical trial of SPK-9001, an investigational gene therapy for individuals with hemophilia B. These data were presented by Adam Cuker, MD, during the Hemostasis and Thrombosis Research Society’s 2017 Scientific Symposium in Scottsdale, Arizona on April 7th. Cuker is an assistant professor of medicine at the Perelman School of Medicine of the University of Pennsylvania and a clinical investigator at Children’s Hospital of Philadelphia.
The presentation included post-infusion data from 10 participants who received a single administration of SPK-9001. Spark is developing the therapy in collaboration with Pfizer Inc., as part of the SPK-FIX program which was established in December 2014 with the goal of developing and commercializing novel gene therapy-based treatments for hemophilia B. SPK-FIX utilizes Spark’s proprietary bioengineered adeno-associated viruses (AAVs), which act as delivery vehicles, or vectors, to carry the genetic codes that prompt the FIX production. The approach being tested in this trial uses a modified novel AAV vector to deliver the corrected FIX gene into liver cells where the protein is normally made.
In a press release preceding the presentation, Spark reported that all participants have experienced “consistent and sustained increases in factor IX activity” following administration of SPK-9001. Data as of March 24, 2017 showed that all participants have discontinued routine infusions of factor IX concentrates. The mean steady-state FIX activity level for the 10 participants 12 weeks after receiving the therapy was a sustained 33%.
Annualized bleeding rate among the 10 patients was reduced by 96% to a mean of 0.39 annual bleeds, compared with 9.2 bleeds before SPK-9001 administration. In addition, annualized infusion rates were reduced 99% to a mean of 0.98 annual infusions, compared with 68.5 infusions before SPK-9001 administration.
Two patients who showed a transient asymptomatic elevation in liver enzymes and drop in FIX activity, potentially indicating an immune response, were treated with oral corticosteroids. Liver enzyme levels and FIX activity subsequently normalized in both patients.
“The additional preliminary data continue to support our initial observations that a single intravenous administration of SPK-9001 has resulted in consistent and sustained levels of factor IX activity for trial participants,” said Katherine A. High, MD, president and chief scientific officer at Spark Therapeutics. “Notably, all participants to date have consistently achieved our targeted therapeutic range of FIX activity.
Source: Spark press release dated April 6, 2017