Note: The following is an edited version of a press release from Spark Therapeutics.聽Read the press release from Spark Therapeutics聽in it鈥檚 entirety here.

Spark Therapeutics recently announced that 10 participants in its ongoing Phase 1/2 clinical trial of聽SPK-9001 for hemophilia B, as of the June 5, 2017 data cut off, had their AIR reduced approximately 99 percent to a mean of 1.0 annual infusion as of the data cut-off date, compared with 67.5 annual infusions before聽SPK-9001聽administration. Nine of the 10 participants have not experienced a bleed since vector infusion; overall ABR was reduced by approximately 96 percent to a mean of 0.4 annual bleeds, compared with 11.1 bleeds before聽a single administration of 5 x 1011 vector genomes (vg)/kg body weight of SPK-9001. These data represent approximately 9.63 cumulative patient years of SPK-9001exposure from the start of the trial, with one participant out approximately 18 months post-infusion and four additional participants out at least one year post-infusion. All 10 trial participants have shown consistent and sustained increases in factor IX activity level and a discontinuation of routine infusions of factor IX concentrates. Their mean steady-state factor IX activity level, or the average of each participant鈥檚 average activity level after 12 weeks, was 33 percent.

The interim data was聽presented聽at ISTH 2017 Congress in Berlin.

Sign up for E-mails, Dateline Magazine, and other ways to stay connected.