SPK-8011 stabilizes Factor VIII levels in Phase I/II for hemophilia A

Spark Therapeutics Inc. (NASDAQ:ONCE) reported preliminary data from a Phase I/II trial showing that a single IV dose of its gene therapy candidate SPK-8011 stabilized Factor VIII activity levels at 14% and 11% of normal in 2 patients with hemophilia A at weeks 12 and 23, respectively. SPK-8011 is an adeno-associated virus (AAV) vector that delivers the Factor VIII gene.

On its 2Q17 earnings conference call, Spark said the company hoped to achieve Factor VIII activity levels of 12% of the normal range, as “well established natural history data” show that there is no risk of annual joint bleeds at the 12% level. The company said there have been no serious adverse events, Factor VIII inhibitor development, thrombotic events or spontaneous bleeds. A third patient is receiving SPK-8011 at twice the dose level of the first 2 patients. Spark told BioCentury that the company has not observed elevated liver enzymes in any of the 3 patients...