Treatment Designed to Prevent Vision Loss
by Tom Hoglund, Originally published in Update, Winter 2003 Issue

GenVec, Inc., a biopharmaceutical company based in Gaithersburg, Maryland, has launched a small, phase 1 clinical trial testing gene therapy in the wet form of age-related macular degeneration (AMD). This is the first time gene therapy treatment for retinal degenerative disease has reached human clinical trials.

“This is a huge milestone for gene therapy. The Foundation hopes to see gene therapy clinical trials for a number of retinal degenerative diseases in the near future,” said Dr. Gerald Chader, Chief Scientific Officer of The Foundation Fighting Blindness.

The GenVec treatment uses gene therapy to treat the eye with the gene that encodes pigment epithelium-derived factor (PEDF). Expressed in retinal pigment epithelial cells that line the retina, PEDF’s protein product is thought to be a natural regulator of blood vessel growth. In previous experiments, PEDF inhibited blood vessel growth by as much as 90% in rodent models. Further work in patients with AMD found that levels of PEDF are abnormally decreased.

Because this gene therapy treatment is highly experimental, enrollment in the GenVec clinical trial is limited to patients with severe AMD. In this way, the safety of the treatment can be evaluated without exposing patients with good central vision to undue risk. The trial will evaluate up to 8 different doses of PEDF in a total of 51 patients.

PEDF has great potential in treating the entire spectrum of retinal degenerative diseases. Besides being a potent inhibitor of blood vessel growth, PEDF has also been found to slow photoreceptor cell degeneration. Additional information on GenVec is available at its web site located at www.genvec.com.