People with the bleeding disorder hemophilia A require lifelong treatment, which would include regular infusions of a clotting promoter factor VIII. Treatments could be expensive and time-consuming. Since they require injections, patient adherence can become a huge issue. Hence,  gene therapy could be a life-changing solution.

In a phase 1/2 trial for Hemophilia A gene therapy by Spark Therapeutics, results showed that it could reduce bleeding by 97%, as per the data reported in December which suggested that it may not be as effective as a rival in development at BioMarin. The study was tested using three different doses of SPK-8011 treatment, designed to treat hemophilia A.

The treatment triggered an immune response in two patients which had dropped their factor VIII levels to less than 5%. One of the patients didn’t respond to oral steroids and had to be hospitalized.

In order to avoid this immune response in the future, Spark will add prophylactic oral steroids to its treatment.

Katherine High, M.D., the R&D chief and the President of Spark said, “These early data further support the dramatic impact on patient outcomes that can result from factor activity levels above 12% and bring us closer to our goal of one day eliminating spontaneous bleeding altogether, while potentially freeing patients with hemophilia A from the need for regular infusions.”