Clinical Trial’s 13 Years of Follow-Up: Gene Therapy Is Effective, Safe for Hemophilia B скачать в хорошем качестве

Clinical Trial’s 13 Years of Follow-Up: Gene Therapy Is Effective, Safe for Hemophilia B

The follow-up data from a 13-year clinical trial evaluating a gene-transfer-based gene therapy approach for treating hemophilia B were recently published in The New England Journal of Medicine. Heme Today spoke with two members of the investigative team who conducted the trial; principal investigator Ulrike Reiss, MD, the director of the Hemophilia Treatment Center at St. Jude Children’s Research Hospital, Memphis, Tennessee, and Andrew Davidoff, MD, chair of the Surgery Department and the director for Surgical Research at St. Jude. The treatment agent assessed in the clinical trial was scAAV2/8-LP1-hFIXco, an adeno-associated virus (AAV)-mediated gene therapy. The vector was administered as a one-time intravenous (IV) infusion to ten men who had severe hemophilia B. The study team then monitored this cohort over 13 years. In terms of circulating clotting factor IX expression in patients, the results the team observed from the gene therapy, over the long-term monitoring of the cohort, were encouraging. Dr. Reiss and Dr. Davidoff described how the clinical benefit associated with the single infusion persisted over the 13-year follow-up period. “The significant finding was [that] the activity of the replaced clotting factor lasted for the duration of the study without really declining over time. That’s the first time that long-term successful gene therapy has been achieved,” Dr. Davidoff summarized. Illustrative of these positive long-term factor IX effects was that several patients in the cohort with severe disease, who required once or twice weekly IV factor IX infusions, were able to discontinue such infusions and remain off them over the 13-year follow-up period. Another positive development was the clinically meaningful, sustained decrease in bleeding rates that the patients experienced. “This treatment has taken off a lot of burden of the disease for all these patients, all 10 participants, even the patients who still continue prophylaxis have had significant benefit with reduction in their bleeding rate and reduction in having to treat with additional factor any bleed events during that time,” Dr. Reiss elaborated. The investigators each highlighted that the results demonstrated the safety of the gene therapy vector treatment, with no significant toxicities or side effects observed over 13 years of follow-up.