Gene Therapy

The identification of mutations underlying human diseases has
led to a better understanding of the pathogenesis of these
disorders and an expectation that genetic modification may
play a significant role in future treatment strategies. No such
treatments are currently available, but many gene therapy trials
are underway.
The first clinical trials in humans were initiated in 1990 and
since then over 150 have been approved. Most of these have
involved genetic manipulation in the therapy of cancer, some
have involved infectious diseases or immune system disorders
and a few have involved inherited disorders, notably cystic
fibrosis. Human trials are all aimed at altering the genetic
material and function of somatic cells. Although gene therapy
involving germline cells has been successful in animal studies
(for example curing thalassaemia in mice) manipulation of
human germline cells is not sanctioned because of ethical and
safety concerns. So far, results of human gene therapy trials
have been disappointing in terms of any long-term therapeutic
benefit and many technical obstacles remain to be overcome.