ASH: Spark highlights promise of gene therapy
- A gene therapy from Spark Therapeutics and Pfizer showed a sustained response in an early trial with a small number of hemophilia B patients, according to data presented this weekend at the annual American Society of Hematology meeting.
- The Phase 1/2 trial of SPK-9001 showed that that one injection of the gene therapy was able to stop spontaneous bleeds from two months and even up to one year in nine patients.
- The first patient in the study, who was followed for 52 weeks post infusion of SPK-9001, no longer needs clotting factor infusions and has a steady-state Factor IX level of 33%. He previously had to infuse clotting factor 99 times over the year prior to getting the gene therapy.
While the trial from Spark and Pfizer is a small one that is particularly early and still needs further follow-up, it offers patients with the debilitating bleeding disorder a ray of hope.
Hemophilia B patients are missing or insufficient in clotting Factor IX, leading to spontaneous and uncontrollable bleeding. Current treatments for the disorder require multiple infusions of the clotting factor each week. Several companies are currently working on gene therapies that could potentially provide patients with the convenience of infusions only once or twice a year.
Factor levels above 5-10% are thought to be the minimum levels needed to control bleeding. Seven of the nine patients in the study who were infused at least 12 weeks ago had levels over 28%.
Two of the nine patients experienced elevated liver enzymes, which can be an indication of an immune response to the gene therapy that would prevent it from working, were treated with corticosteroids and have not had any breakthrough bleeds or required further clotting factor infusions.
Jefferies analyst Gena Wang wrote in a Dec. 5 note that SPK-9001 could be "best-in-class" but needs further follow up to make sure patients don't need consistent steroid therapy.
The companies intend to meet with the Food and Drug Administration in the first quarter of 2017 and discuss the trial design for a Phase 3 trial, which will likely include no more than 100 patients.
- Spark Therapeutics Statement
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