UC Santa Barbara’s Dennis Clegg is taking stem cell-based therapy for AMD to clinical trials.
Age-related macular degeneration (AMD) is the leading cause of vision loss in the United States among people age 50 and older. It is estimated that 11 million people in the United States have some form of age-related macular degeneration, and the number is expected to double by 2050.
Pioneering research using stem cells to regenerate eye tissue conducted by UC Santa Barbara’s Dennis Clegg and co-workers may one day help people with AMD. As the first person to hold the newly endowed Wilcox Family Chair in BioMedicine, Clegg, a professor in UCSB’s Department of Molecular, Cellular and Developmental Biology, is poised to bring stem-cell-based therapy for AMD to phase one clinical trials.
Supported by a generous gift from UCSB alumni Sue and Gary Wilcox, the chair is designed to further pre-translational work on human biological systems that may lead to clinical studies.
“I am so grateful to Gary and Sue Wilcox for their generosity in creating the Wilcox Family Chair in BioMedicine,” said Clegg, who is also a co-founder of campus’s Center for Stem Cell Biology and Engineering. “It will help fund innovative, high-risk, high-gain research as well as provide seed money to support students and postdoctoral scholars.”
Clegg is also co-director of the California Project to Cure Blindness, a collaborative effort aimed at developing a stem-cell-based therapy for AMD. The project is funded by the California Institute for Regenerative Medicine (CIRM), the state’s stem cell agency. Partners in the project include the California Institute of Technology (Caltech), the University of Southern California (USC), the City of Hope and University College London.
AMD takes two forms: wet and dry. In the wet form, for which treatment is currently available, growth of abnormal blood vessels causes blood and fluid to leak into the retina, resulting in vision distortion, blind spots and, ultimately, loss of central vision.
The dry form of the disease, which has no treatment and is the focus of Clegg’s research, is caused by the presence of yellow deposits in the eye’s macula. As these deposits grow in size and increase in number, vision is dimmed and distorted. A concomitant thinning of the light-sensitive layer of cells in the macula eventually leads to the death of a cell type called retinal pigmented epithelium (RPE). These are the support cells for the rods and cones — the eyes’ photoreceptors, which allow light to be translated into recognizable images.
“It’s especially devastating because the visual defect occurs in the macula, which is the center of the retina,” Clegg explained. “That part is used for high acuity vision, so people with the disease end up with a big blank spot in the middle of their field of vision. Some reports estimate that more than 30 million people worldwide have this disease, so there is a real unmet medical need for a therapy.”