Tuesday, August 29, 2006

Gene Therapy

The LA times has an interesting and informative article on recent advances (and setbacks) in gene therapy here. Here is a snippet from the article:

TO the shrill whine of a high-speed drill, neurosurgeon Dr. Paul Larson makes two nickel-sized holes in Shirley Cooper's skull. Guided by a computerized MRI map, he plunges a long, thin needle through one hole and deep into the brain — and empties the syringe. A very special payload trickles into her brain: genes that, if all goes well, will help her control the movement of her muscles.

It is a day in late May and Cooper, 60, an artist who lives near Seattle, has come to the UC San Francisco Medical Center to find some relief from the Parkinson's disease that is stealing her identity. Without medication, she has trouble walking and talking, and can't hold a paint brush. And the drugs are wearing off — as they eventually do for all Parkinson's patients. After that, she probably will deteriorate rapidly.

The experimental treatment Cooper is undergoing is intended to reverse that process. Parkinson's destroys cells in the brain that make dopamine, and the loss of this key brain transmitter triggers the disease's crippling symptoms: tremors in the arms, legs and face, stiff or frozen limbs, and impaired balance and coordination. In the trial she's involved in — the earliest of clinical tests, designed to assess safety — scientists have engineered a harmless, stripped-down virus to carry a gene that will boost brain dopamine through the enzyme it encodes: amino acid decarboxylase, or AADC.

....Gene therapy is making a comeback after a series of serious setbacks that threatened to permanently derail human tests. In recent years, European scientists have cured more than two dozen patients suffering from three rare, and in some cases lethal, immune disorders.

Spurred by this success, plus the development of new techniques aimed at making the therapy safer and more effective, more than 300 gene therapy trials, including the one for Parkinson's at UC San Francisco, are underway in the U.S. and abroad.

There are 790 approved gene-therapy trials in America and 338 in Europe. See this site for some useful charts on gene therapy trials. The approval of the first commercial gene therapy product was recently reported in the journal Human Gene Therapy (September 2005).