Spark announces results of long-term trials of hemophilia A gene therapy.

Haemophilia is a rare hereditary haemorrhagic disease that takes a long time for blood to clot due to a lack of several coagulation factorsThe incidence of haemophilia A is about 4 times that of haemophilia BHemophilia A is characterized by mutations in genes that encode coagulation factor VIII, leading to a defect in clotting function and an increased risk of bleedingAt present, the standard method for treating haemophilia A is to control and prevent bleeding by repeated intravenous infusion plasma source or recombinant coagulation factor VIIIHemophilia patients have a strong need for innovative therapiesSPK-8011 is a new adenovirus (AAV) carrier using AAV-LK03 shell, carrying a cryptocogen-optimized human coagulation factor VIIIThe U.SFood and Drug Administration (FDA) has granted this treatment in the rapy orphan drug qualification and breakthrough therapy recognitionIn this Phase 1/2 clinical trial, a total of 14 patients were treated with SPK-8011, two of them received low doses (5E11 vg/kg), 3 received medium doses (1E12 vg/kg) and 9 received high doses (2E12 vg/kg) gene therapyTwo patients treated with high-dose gene therapy for the lack of coagulation factor VIII expression, possibly due to the patient's immune response to the adeno-related virus shellThe remaining 12 patients showed stable and persistent coagulation factor VIII expressionAll 14 subjects showed the ability to quickly remove AAV vectors from semen, serum, saliva and urine within 2 weeks of receiving AAV vector administrationAfter 6 weeks of administration, AAV vectors were not detected in all subjects' peripheral blood mononucleosis (PBMC), semen, serum, saliva, and urineDr Federico Mingozzi, Chief Scientific Officer of Spark Therapeutics, said: "We are very encouraged by these interim data, which continue to show an acceptable safety and a significant reduction in bleeding in patients over an average of more than two years of observationOur research and development focuses on optimizing dose and immunomodulation programmes prior to the entry of Phase 3 clinical studies and demonstrating the safety, predictability, effectiveness and persistence of hemophilia A gene therapy at the lowest effective dose and the best immunomodulation programmeThe original title: ExpressA treatment reduced the patient's bleeding rate by 91%, Spark announced the results of long-term trials of haemophilia A gene therapy References: 1 Spark Therapeutics Alex Update d Data on SPK-8011 from Phase 1/2 Clinical Trial in Hemophilia A at ISTH 2020 Virtual Congress Retrieved July 12, 2020, from