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Quality of Life for Patients with Haemophilia Patients May Potentially Improve with Gene therapy
March 10, 2017-Hong Kong, China — Patients with haemophilia B, who areunable to produce factor IX, began producing sufficient levels factor IX at after theyreceived a single infusion of SPK-9001, an investigational gene therapy product.
This outcome from preliminary data of an ongoing phase 1/2 trial, was reported at the58th Annual Meeting of the American Society of Hematology, from December 3 – 6.
Katherine A. High, MD, of Spark Therapeutics, Inc., Philadelphia, Pennsylvania,explained that patients with haemophilia B need to self-infuse intravenous laboratory-produced factor IX at regular intervals, typically once to twice a week.Factor IX levels fluctuate widely, and patients may need to limit their activities to avoidbreakthrough bleeding when their factor IX levels are low.
The ongoing trial involves seven previously treated adult patients with haemophilia withan extremely deficient, baseline factor IX < 2%.
Twelve weeks after SPK-9001 infusion, patients exhibited factor IX levels of 20 – 40%,and an overall average of 32%. This level is sufficiently close to normal (at least 50% inhealthy adults). Maintaining a minimum level of 12% prevents minor, chronic jointbleeding, a common cause of disability in patients afflicted with haemophilia.
SPK-9001 employs an inactive adenovirus vector that delivers a small section of DNAthat, when stabilised in the patient’s hepatocytes, allows the body to produce factor IX.
Factor IX levels achieved with SPK-9001 have been sufficient to allow patients to engagein normal daily activities without the need for factor IX infusions.
Though none of the seven participants have required infusions of factor IX concentratesto prevent bleeding, one precautionary infusion was needed due to a suspected anklebleed 2 days after administration of SPK-9001. Six patients reported increased physicalactivity and better quality of life.
Dr High said, “One of the potential innovations of gene therapy for haemophilia B vsfactor IX infusions is that once patients establish a stable factor activity level, they mayremain at that level for extended periods.”
“At the factor IX levels attained in the study, patients with haemophilia do not have toworry about bleeding. Most normal activities of daily living should be open to them. Thetherapy could mean a potential paradigm shift in the treatment of haemophilia.”
One participant suffered an autoimmune response and needed corticosteroids. Despite theimmune response and decline in factor IX activity level, this patient has not experiencedany bleeds or required replacement factor IX.
Dr High concluded that the results demonstrated the highest and most consistent levels offactor IX production of any gene therapy evaluated to date. Dr High and her team plan tocontinue to monitor patient outcomes for at least 5 years.