Turning Genetic Knowledge Into Therapies

June 29th, 2015 by FFB Canada

Taking research from the laboratory to the clinic takes time, dedication, patience and planning, and it also requires a broad network of supporters.  Here at the Foundation Fighting Blindness, we began funding Dr. Ian MacDonald’s choroideremia research in 1985. Today we are thrilled to announce that his first clinical trial of a gene therapy for treating choroideremia has officially begun. “This new step forward is extremely meaningful,” says Sharon Colle, FFB President & CEO. “We believed in the translational potential of Dr. MacDonald’s work since the very beginning and are extremely proud to be supporting the first clinical test of his research. This trial gives us hope and proof that laboratory science has the potential to transform into clinical research.”

Choroideremia is a rare condition that travels through families on the X chromosome. An affected man will have unaffected sons and daughters who have a 50% chance of transferring the damaged gene to their own sons.

In the 1980s, scientists did not know what gene caused choroideremia, but the pattern was evident. As a post-doctoral fellow in clinical genetics, Dr. Ian MacDonald was urged to study it by Barbara Owens, a reporter for the Ottawa Citizen whose cousins and uncles lived with the disease.

Ms. Owens was a family tree enthusiast. She was able to identify an ancestor, who arrived in Ontario in 1849 apparently affected by choroideremia. Building on her information, Dr. MacDonald was able to identify 1800 family members and traced the inheritance of the disease.

With the support of Foundation donors, Dr. MacDonald was then able to localize the gene to a particular portion of the X chromosome, and to develop the first predictive test for a genetic eye condition to determine which family members were at risk.

In the years since, Dr. MacDonald has become an international expert on choroideremia. When the exact gene that causes choroideremia was identified by UK scientist Dr. Miguel Seabra, the two men collaborated to create the screening test now used globally to test for the disease.

Today, Dr. MacDonald continues to collaborate with Dr. Seabra, and ophthalmological surgeon, Dr. Robert MacLaren to test the first therapy for choroideremia. The therapy is a potential model for the treatment of many retinal diseases.

The first clinical trials took place at the University of Oxford. Results published in The Lancet Medical Journal in 2014 reported that six months after treatment, the first six patients showed improvement in their vision in dim light; and two of the six were able to read more lines on an eye chart. Oxford research is ongoing under the direction of ophthalmologist Dr. Robert MacLaren.

Researchers believe this new approach to eye therapy has promise for treating people early on before too many cells in the retina have been lost. It may also have relevance for other, far more common causes of blindness, such as retinitis pigmentosa and age-related macular degeneration.

Dr. MacDonald says he’s “absolutely impressed” by the eye’s ability to heal itself and reattach the retina within hours of surgery. “The human body is doing its work. We’re just helping it.

Thanks to the Foundation Fighting Blindness community for making this possible!

Sources:

You can read more about Dr. MacDonald’s work in our report: Celebrating 40 Years of Discovery. 
Media credit: With help from Gregory Kennedy, Alberta Health Services Communications