Pathology: In normal vision, absorption of a photon of light initiates a signaling cascade which results in the visual pigment rhodopsin triggering light perception in the brain. In the final stages of the vision cycle, all-trans-retinal (ATR), an intermediary in this process, gets isomerized back to its starting conformation so the vision cycle can begin again. However, in Stargardt's disease and AMD, ATR is not cleared properly, which leads to the formation and accumulation of cytotoxic metabolites.
Compelling Technology: Several companies are developing therapies to completely shut down all-trans-retinal, however this disturbs the natural vision cycle and can cause night blindness.
Visum's novel approach proposes to develop drugs that will temporarily control levels of ATR in the eye and preserve the natural vision cycle, leading to a therapeutic treatment.
Visum has identified a lead compound, VSM 20R, which is an enantiomer of an FDA approved drug that demonstrates complete retinal protection in preclinical studies.
Unique Approach: Visum has discovered a unique chemical approach to sequester rather than eliminate ATR. Through this process, 25 diverse FDA approved drugs demonstrating both mechanistic and in vivo efficacy have been identified. A PCT application has been filed, which covers the lead compound (VSM 20R), the 25 FDA approved drugs, and numerous others identified in a high throughput screen that work via this mechanism. VSM 20R does not have the liabilities of the approved drug, as it has been shown to be inactive for the FDA approved pharmacology.
Visum has also identified a fluorescent biomarker that can track drug efficacy and disease progression through noninvasive imaging. This biomarker is suitable for clinical trials and has shown a compelling dose/efficacy relationship with Visum's compounds. By utilizing a drug that has already been proven to be safe in conjunction with a biomarker that can track efficacy, Visum anticipates a low-risk Phase I clinical trial.
Visum will pursue a Phase II study of VSM 20R in Stargardt's disease, which is designated as an Orphan Disease and can therefore offer faster registration and lower risk. Since Stargardt's disease is a juvenile form of macular degeneration, this study can facilitate entering the much larger AMD market in the future.
Market potential: Stargardt's disease is an orphan disease with approximately 20-25,000 patients in the United States. For comparison, the wet form of AMD utilizes Leucentis at a cost per patient of $12,000 per year. Estimating a 50% market penetration, Stargardts disease can be a $100-150 million opportunity. If our therapies were expanded to include treating dry AMD, an unmet medical need, with a market of over 1.5 million patients, this could represent a $10 billion market opportunity.