Four Promising Advances in Gene Therapy Research
Gene therapy was introduced as a theory in 1972, and the first attempt to transfer a human gene took place in the 1980s. The treatment was unsuccessful, and since then, there have been exponential improvements in hemophilia research and education.
Today, the questions at hand are, “What is the goal of gene therapy?” and “What is the future of gene therapy research for hemophilia?” The answer is to replace a faulty gene with a fully-functioning one. In this article, we’re going to take a closer look at four promising advances in gene therapy research to meet that goal:
1. Gene therapy AMT-060 prevents bleeds for up to five years
AMT-060 is uniQures first-generation gene therapy treatment, and it continues to reduce bleeding episodes in participants with hemophilia B. Also, eight out of nine men in the study were able to stop their current prophylactic treatments.
AMT-060 uses a modified version of the adeno-associated virus variant 5 to deliver a functioning copy of the FIX gene. Delivery is through a single injection into the bloodstream. The data shows that this treatment prevents bleeds for up to five years. These findings were offered at the 62nd Annual Meeting & Exposition of the American Society of Hematology, held virtually in December.
2. AMT-061 successfully increased factor IX activity and controlled bleeding for hemophilia B
AMT-061 from uniQure is an investigative gene therapy for the treatment of hemophilia B. At the 62nd Annual Meeting & Exposition of the American Society of Hematology, the company presented findings that show the therapy successfully increased factor IX (FIX) activity and controlled bleeding in hemophilia patients.
AMT-061 uses an AAV5 viral vector to deliver a version of the FIX gene with high FIX activity. Hemophilia B is caused by missing or defective FIX clotting protein, and the delivery allows hemophilia B patients to produce functional FIX.
The study involved 54 men with a median age of 41.5. Each was given a single dose of the AMT-061 treatment via intravenous infusion. The therapy was well-tolerated; however, 37 participants reported mild adverse events, including increased liver enzymes, headaches, and flu-like symptoms.
They did see a decrease in bleeds, though. 39 patients saw no bleeds during the trial.
3. A single dose of gene therapy BAY 2599023 safely promoted sustained production of factor VIII (FVIII)
BAY 2599023, formally called DTX201, is an experimental gene therapy for hemophilia A developed by Bayer with Ultragenyx Pharmaceuticals. In its clinical trial, two out of the six participants are still showing FVIII activity a year after their single dose.
BAY 2599023 uses a modified version of the adeno-associated virus (AAVhu37) to deliver a shorter but functional copy of FVIII to the patient. Individuals with hemophilia A cannot produce or have limited quantities of FVIII. Two patients were given the lowest dose of BAY 2599023, and it was well-tolerated. Testing found that it effectively increased levels of FVIII and prevented occurrences of bleeds.
Two patients were given a low-medium dose of the therapy and saw increases in FVIII levels. They were also able to stop prophylactic treatments, although one of the two men did have a slight elevation in liver enzymes.
The two final participants received a high-medium dose of BAY 2599023. Both men had mild to moderate elevations in liver enzymes. One man had a traumatic bleed during the trial that was resolved without an infusion of clotting factors.
4. BioMarin’s gene therapy prevents bleeds after four years
Valoctocogene roxaparvovec from BioMarin Pharmaceuticals is an investigational gene therapy that effectively prevents bleeding episodes after four years. This gene therapy, formally called BMN 270, uses a modified version of the adeno-associated virus to deliver a functional copy of the FVIII gene. Results show that all study participants can remain off of prophylaxis treatments for factor VIII, and their ABR continues to be low.
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