Gene therapy in the clinic

Gene therapy is thought as a novel method of therapy. The first clinical trial was performed in 1990. The correction of genetic monogenic disorder, severe combined immunodeficiency by retrovirus transfer of normal adenosine deaminase gene to the lymphocytes of patients was well described. So far, the number of clinical trials has rapidly increased. Cancer, monogenic diseases, vascular and infectious diseases are the main targets of clinical gene therapy. The sufficient gene transfer is possible using effective vectors. The retroviral and adenoviral vectors are most frequently used in the clinic but very often the naked/plasmid DNA is also useful. Mostly the therapeutic genes are transferred into the liver, skeletal muscles, heart, central nervous system, lungs, skin, pancreas and blood cells. The genes are administered directly to target tissues or indirectly by intravenous or intramuscular injections. Quite often gene therapy is the only method for no option patients who are not suited to conventional therapies. Many hopes are linked with the gene therapy of vascular diseases and application of various expression vectors encoding angiogenic factors for the treatment of heart or hind limb ischemia. Overexpression of angiogenic genes, for example vascular endothelial growth factor (VEGF) or fibroblast growth factor (FGF) cause the formation of new vessels and improve the clinical state of patients. The first clinical trials of angiogenic gene therapy with the plasmid encoding vascular endothelial growth factor have been also performed in Poland.