With an aging population and rising rates of vision loss, the U.S. pharmaceutical and medical device industries have latched onto ophthalmology as an area where innovation is both needed and lucrative.
Cleveland-area startup Visum Therapeutics is one of the companies going after an orphan eye disease called Stargardt disease, which is a juvenile manifestation of macular degeneration that’s thought to be caused by a genetic deficiency rather than age.
CEO Bill Harte said the company started with a simple idea from the lab of Krzysztof Palczewski, the chairman of the Department of Pharmacology at Case Western Reserve University, whose years of vision research has been published in more than 300 papers. That idea involves a chemical called all-trans-retinal that’s part of the vision cycle. In patients with Stargardt’s, the transporter that clears ATR from the retina doesn’t work properly and causes the chemical to build up. Palczewski’s idea, Harte said, is that the flawed clearing of ATR is the fundamental insult in almost all retinal degenerative diseases.
His next idea was that, rather than stopping the production of ATR, which would impede the vision cycle, a better solution would be to temporarily control levels of the chemical in the eye. Palczewski knew that there were approved drugs on the market that performed the chemical function needed to do this, so he tested 25 of those compounds in mice models of the disease. Sixteen of them were efficacious, but one in particular emerged as a clear retinal protectant and lent itself to easy modification for removal of the U.S. Food and Drug Administration-approved activity, so that it could be tested in eye disease.
That candidate, VSM 20R, was licensed from Case Western Reserve and has been taken through pharmacological and preliminary toxicity studies in animals, Harte said. The next step is completing the series of animal studies that will allow the company to file an IND application with the FDA. That, he said, will require $2.5 million from investors, in addition to some funds committed by the Foundation Fighting Blindness, if Visum can find additional partners.
Because of the similarity in the etiology of Stargardt’s and age-related macular degeneration, Harte said Visum will pursue the drug as a treatment for dry AMD as well, for which drug development efforts have been slow in comparison to the busy market for wet AMD treatments.
There are no FDA-approved drugs for dry AMD or Stargardt disease, but several other companies have their eyes on the same markets. Among them are Acucela and GlaxoSmithKline, which have drugs in phase 2 trials. ScyFIX is taking the device approach and is using electrodes placed around the eyes to deliver microcurrent neuromodulation.
There are also companies taking higher-risk approaches. Oxford Biomedica, for example, is conducting a phase 1/2a study of its gene therapy in Stargardt patients. Advanced Cell Technology has orphan drug designation for its MA09-hRPE cells for use in Stargardt disease and is testing the embryonic stem cell-derived therapy in a phase 1/2 study.
Visum’s drug candidate wouldn’t reduce damage to the retina, but it could provide an option to help prevent further degradation. “You can actually see pretty well with 50 percent of the retina gone,” Harte said. “We’re trying to give someone 10 years of additional seeing.”