IP Review Summer 2018

3 The reinvention of human gene therapy Gene therapy is a technique in which a correcting gene is delivered to a patient in order to treat or prevent disease. In many instances, this gene replaces a defective gene which is the underlying cause of the disease. For example, some forms of haemophilia are the result of a mutation in a single gene which causes a key protein in the blood clotting system not to work correctly. The first gene therapy trial was approved in 1990. The therapy was given to two children who had severe combined immunodeficiency (SCID) which was caused by a defect in the gene encoding the enzyme adenosine deaminase (ADA). This gene therapy sought to insert a correct version of the ADA gene so that the children’s immune system could work effectively. Whilst it was shown that the functional ADA enzyme was present in the children following treatment, unfortunately, the level of ADA was too low to show a clinical benefit in treating the SCID. + Cover Story The concept of gene therapy has been around for over 25 years. At its inception, it was hailed as a powerful new technique for treating previously incurable genetic disorders. Unfortunately, the initial hype did not materialise into approved medicines and the field went out of favour, with many biotech companies looking for alternative therapies for human disease. However, in recent years, there appears to have been a revival with a number of approved medicines on the market and more in the pipeline.