Spark Therapeutics' Hemophilia Gene Therapy Shows Reduction In Bleeding Episodes

Spark Therapeutics, a unit of Roche Holdings AG RHHBY, has announced data from its Phase 1/2 trial of SPK-8011 in hemophilia A.
At a median efficacy follow-up of 33.4 months, the study found that 16 of 18 study participants had sustained factor VIII (FVIII), which permitted prophylaxis cessation and reduction in bleeding episodes.
The latest results were published online in the New England Journal of Medicine (NEJM).
The updated analysis (cutoff May 3) of all 18 study participants demonstrated a 91.5% reduction in annualized bleed rate (ABR) and a 96.4% reduction in the annualized number of FVIII infusions.
Related Link: Spark Therapeutics' Hemophilia Gene Therapy Achieve Stable, Durable FVIII Expression.
In the safety analysis, 33 treatment-related adverse events (AEs) occurred in 8 participants, of which 17 were vector-related, including one serious AE, and 16 were glucocorticoid-related.
As previously reported, two participants lost all FVIII expression due to an anti-AAV capsid cellular immune response, unresponsive to immunosuppression.
The remaining 16 participants maintained FVIII expression.
Price Action: RHHBY shares closed at $49.86 on Wednesday.