By James DeGiulio --
Earlier this year, we reported on the therapeutic potential of gene therapy experiencing a revival of sorts after falling out of favor for over 10 years (see "Gene Therapy Experiencing a Revival"). That revival continues, as evidenced by a press release issued by GlaxoSmithKline on Monday, in which the pharmaceutical company reports that it has licensed a gene therapy treatment for a rare disease that afflicts just 350 children worldwide. Following its recent formation of a rare disease unit, GSK has allied with two Italian groups, Fondazione Telethon and Fondazione San Raffaele, and has obtained an exclusive license to develop an experimental gene therapy for a disease called ADA severe combined immune deficiency (ADA-SCID).
The ADA-SCID gene therapy news may remind some of the infamous 1999 attempt to cure the related disease severe combined immune deficiency using gene therapy. Unfortunately, due to carcinogenic viral integration, the therapy caused leukemia in some of the patients. While ADA-SCID is similar to severe combined immune deficiency, the techniques used in this gene therapy treatment are different, and the Italian group has provided very promising results. In this ex vivo stem cell therapy, the patient's hematopoietic stem cells are harvested from the body, functional copies of the gene are inserted into the stem cells using a modified viral vector, and the cells are re-introduced to the patient. Because the technique uses the patient's own cells, there is much less risk of immune rejection compared to a bone marrow transplant, which is currently the best treatment option available. Most importantly, the ex vivo technique appears to be extremely safe. On July 22, 2010, the San Raffaele Telethon Institute group published an article in the New England Journal of Medicine showing successful treatment in 8 of 10 children without substantial side effects, including no leukemia cases observed after four years.
GSK also plans to work with the Italian researchers to develop ex vivo stem cell therapy for six other rare diseases, with the potential to treat a range of rare disorders. The first two disorders will be metachromatic leukodystrophy and Wiskott-Aldrich Syndrome -- clinical trials for both of these disorders were initiated last spring. Others include beta-thalassemia, mucopolysaccharoidosis type I (MPS), globoid leukodystrophy (GLD), and chronic granulomatous disorder (CGD). All of these disorders have molecular mechanisms that are well understood and all are caused by faults in a single gene. GSK's rare disease unit will look at roughly 200 of the 6,000 rare diseases. The unit will not be conducting its own research, but will instead further develop approaches discovered in academia or within other GSK units.
James DeGiulio has a doctorate in molecular biology and genetics from Northwestern University and is a graduate of Northwestern University School of Law. Dr. DeGiulio is a member of MBHB's 2010 associate class and he can be contacted at [email protected]