Atlanta-based Expression Therapeutics recently announced phase 1 clinical trial results based on ET3, the company’s investigational gene therapy. ET3 is developed with novel lentiviral vectors.
This type of therapy uses repurposed retroviruses to introduce a factor VIII transgene to deliver targeted genetic material. The technique involves taking hematopoietic stem cells (a self-renewing cell isolated from blood or bone marrow) from a patient, adding the lentiviral vector and re-infusing it into the body. In this model, the genetic messaging prompts the production of the factor VIII in people with hemophilia A. Ideally, these vectors deliver this genetic material into living cells to achieve a therapeutic effect that is free of unintended adverse reactions in the short and long term.
These results were presented during the 66th American Society of Hematology meeting, which was held December 7-10, 2024, in San Diego, California.
The trial, which is being conducted at the Christian Medical College on Vellore, India, includes five participants with severe hemophilia A, ranging in age from age from 22 to 41. None of these patients had factor VIII inhibitors at the time of study. Leading into the study, all participants reported annualized bleeding rates of no less than 20 events.
Each participant received a single dose of the therapy. According to a new press release, no spontaneous bleeding events occurred in any participant These results were consistent with measured FVIII levels, which in all five participants increased from undetectable to levels predicted to produce therapeutic efficacy. The median follow-up was 14 months (range, 9 to 27 months).
In terms of safety, investigators report that except for neutropenia and thrombocytopenia (which were expected), no adverse events observed amongst participants graded higher than moderate severity. Inhibitors to FVIII did not develop in any participants post gene therapy administration. no safety concerns.
“This Phase I clinical trial produced no unexpected safety issues and remarkable clinical efficacy. Lentiviral vector hematopoietic stem cell therapy offers the hope of permanent cure of hemophilia A patients that ultimately may be extended to the pediatric population,” said Pete Lollar, MD, Chairman of the Board of Expression Therapeutics and Hemophilia of Georgia Professor at Emory University School of Medicine.
The results were also published on December 9th in The New England Journal of Medicine.
Source: PR Newswire, December 11, 2024
Writer: Jonathan Angarola, Senior Manager of Medical Programs & Information
