Spark Therapeutics, Inc. recently released preliminary data from a phase 1/2 dose-escalation clinical trial for SPK-8011, the company’s investigational gene therapy candidate for hemophilia A.

SPK-8011 entails a one-time intravenous infusion, designed to trigger the production of therapeutic levels of factor VIII (FVIII), a protein that is normally deficient in individuals with hemophilia A. Spark Therapeutics’ proprietary bioengineered adeno-associated viruses (AAVs) act as delivery vehicles, or vectors, to carry the genetic codes that prompt the FVIII production. The approach being tested in this trial uses a modified novel AAV vector to deliver the corrected FVIII gene into liver cells where the protein is normally made.

As of the August 1, 2017 data cutoff, two trial participants who have received a single administration of SPK-8011 have been followed for 23 weeks and 12 weeks, respectively. Spark reports that during this period there has been a steady rise in FVIII levels that have now stabilized at 11% and 14% of normal, respectively.

A third participant received a higher dose SPK-8011. While it is too early to cite specific results for this participant, Spark reports that his FVIII activity levels are “tracking proportionally higher,” consistent with the dose escalation. In all, three trial participants have received a single administration of SPK-8011, with no serious adverse events reported to date, including no factor VIII inhibitors and no thrombotic events.

“The encouraging start of our SPK-8011 clinical trial reinforces the strength of our gene therapy platform, delivers human proof-of-concept in a second liver-mediated disease -- a significant achievement in the gene therapy field -- and positions us well to potentially transform the current treatment approach for this life-altering disease with a one-time intervention,” said Katherine A. High, president and chief scientific officer of Spark Therapeutics.

Source: Yahoo Finance, August 2, 2017