Gene therapy for treating haemophilia: working to correct the body’s blood clotting “software”

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euven (Belgium) and Paris (France), April 27, 2010–

VIB, a life sciences research institute in Flanders, Belgium and Cellectis, (Alternext: ALCLS), the French genome engineering specialist, today announced that they are going to collaborate on research into new approaches to cure haemophilia. Thierry Vandendriessche and Marinee Chuah from the VIB Vesalius Research Center at K.U. Leuvenare going to use meganucleases – tailor made enzymes engineered by Cellectis - to replace faulty blood clotting factor genes with functional copies.  

Haemophilia is a group of hereditary, recessive, sex-linked genetic disorders that impair the body's ability to control blood clotting or coagulation. Haemophilia A (clotting factor VIII deficiency) is the most common form of the disorder, occurring in around 1 in 5,000–10,000 male births. Haemophilia B (factor IX deficiency) occurs at about 1 in about 20,000–34,000 male births. Haemophilia patients suffer in various degrees from uncontrolled internal and external bleeding after a blood vessel is broken. In areas such as the brain or inside joints, this bleeding can be fatal or permanently debilitating.  

Genetic therapy has long been considered a rational approach to cure haemophilia. However, one of the major setbacks to date was that new genetic material was inserted anywhere into the DNA, possibly disrupting useful genes, leading to unwanted side effects or the lack of expression of the gene of interest. Cellectis’ meganuclease technology enables accurate insertion of functional copies of the FVIII and FIX genes in a way that does not disturb the other functions of the targeted cell.  

“Meganucleases have the potential to solve the random insertion issue,” commented Vandendriessche and Chuah from the VIB Vesalius Research Center at K.U. Leuven. “The technique allows the new genes to be delivered at a predetermined and safe location, with great precision. We have high hopes that one day, this research will lead to life-enhancing therapies for haemophiliacs.”  

Gene therapy can be compared to reprogramming a cell’s software by uploading a corrective patch. The genetic code is the programming language, the mutated gene is the bug in the software and the meganucleases are the patch.