Israeli researchers to develop medication for incurable eye disease
Retinitis pigmentosa is believed to affect around 1.5 million people globally, with 2,000-3,000 patients in Israel.
By AARON REICHAn illustrative picture of a person's eye. (photo credit: Wikimedia Commons)
Israeli researchers are developing a medication to treat retinitis pigmentosa, an incurable genetic eye disease that causes retina degeneration and blindness at a young age, by recreating a supplement derived from a natural ingredient that no longer exists in sufficient quantities.Retinitis pigmentosa is believed to affect around 1.5 million people globally, with 2,000-3,000 patients in Israel. The disease first manifests early in life, with late onset symptoms appearing in early- to mid-adulthood. A patient's vision will continue to decline as the disease gets progressively worse, which can lead to complete blindness.The disease itself is caused by a genetic mutation that prevents the body from absorbing β-carotene, a pigment that is essential for vision, the lack of which results in vision deterioration and retina degeneration.While there is no cure for the condition, there are many different proposed treatments and medications. One of these was discovered in clinical trials from around a decade ago, which saw a natural food supplement derived from marine algae having success in improving treatment in a third of patients.The specific treatment focused on the active ingredient 9-cis-β-carotene, a version of β-carotene. The ingredient was shown to be absorbed by some of the patients, allowing their vision to improve in several areas – specifically night vision, field of vision and electrical activity in the retina.Later, however, the supplement's effectiveness proved to be more erratic. This was found to be due to environmental factors, which caused a change in the algae, meaning it no longer contained enough 9-cis-β-carotene.However, researchers at Tel Aviv University's Blavatnik Center for Drug Discovery and at Sheba Medical Center have been able to successfully synthesize a stable, man-made form of 9-cis-β-carotene, and are currently developing a drug based on it."When the composition of the natural algae was altered due to changes in its marine environment, we realized that to ensure the drug's reliability we must produce a stable synthetic drug, in which we can control the contents," Dr. Elvira Haimov, head of the center's Medical Chemistry Unit, said in a statement."Our main challenge in developing this drug was the chemical instability of the active ingredient 9-cis-β-carotene, which disintegrates easily in the presence of light and oxygen – a considerable impediment to both manufacturing processes and shelf life," she said. "To address this problem, we developed methods of conservation, mostly by adding stabilizers and antioxidants. Today our project has reached the stage of upscaling – to enable production in larger quantities.""The medication we synthesized was tested successfully on retinal neurons in the lab," the center's managing director Dr. Ludmila Buzhansky explained."Once we are able to produce a sufficient quantity, we will go on to the next stages: more experiments in the lab and on mouse models, followed by clinical trials in human patients," she said. "Since the substance has proven both safe and effective in its natural form, we are very optimistic regarding the potential of the synthetic version."We believe that it will serve as a basis for developing an effective drug that can save the vision of many people suffering from retinitis pigmentosa."
