No need of factor IX infusions in Hemophilia B after single dose of gene therapy

The New England Journal of Medicine has published interim data as of July 25, 2017, from the Phase 1/2 clinical trial of SPK-9001, an investigational gene therapy for hemophilia B. With a cumulative follow-up of 492 weeks' observation of the first 10 adult male participants, the mean steady-state factor IX activity was 34 percent of normal (range of 14-81 percent) following a single administration of investigational SPK-9001. The annualized bleeding rate (ABR) was reduced 97 percent, from a mean rate of 11.1 events per year before vector administration to 0.4 events per year after vector administration (p=0.02), while factor IX concentrate use was reduced 99 percent (p=0.004).

"People who live with hemophilia today face a lifelong need for vigilant monitoring and recurrent factor concentrate infusions to prevent spontaneous, potentially life-threatening bleeds and to protect their joints. The discipline required to execute the usual prophylactic regimen can exact a heavy toll on quality of life, and these regimens result in significant costs to patients, families and the healthcare system," said Katherine A. High, M.D., president and head of Research and Development at Spark Therapeutics and co-author of the paper. "The data suggest a one-time infusion of SPK-9001 has the potential to safely sustain factor IX coagulant activity level that may result in the termination of baseline prophylaxis factor infusions, significantly reduce bleeding, and nearly eliminate the need for exogenous factor IX concentrate infusions."

In this open-label, non-randomized, multicenter Phase 1/2 clinical trial, there were no serious adverse events during or following infusion of SPK-9001, and no participants experienced thrombotic events or developed factor IX inhibitors. Two participants developed an asymptomatic and transient increase in liver enzymes that resolved with a tapering dose of oral corticosteroids. One participant with the severe joint disease has administered factor for suspected bleeding, but overall factor use for this participant was 91 percent lower than before SPK-9001 infusion.

Please refer to the paper, "Hemophilia B Gene Therapy with a High Specific Activity Factor IX Variant," for the full description of the design and interim results of this study.

For more details click on the link: http://dx.doi.org/10.1056/NEJMoa1708538