STARGARDT'S DISEASE

Untreatable and Leading Cause of Childhood Blindness

Stargardt's disease is a rare yet life devastating condition. It is the most common form of inherited macular degeneration, and affects one in 10,000 people (about 30,000 people in the United States). There is currently no cure or treatment for Stargardt's disease. Patients with Stargardt most often start experiencing significant vision loss during their childhood and teenage years (60% of the patients are diagnosed before 20 years of age). This vision loss cannot be corrected by glasses. Diagnosis is often delayed due to the young age of the patients and the rareness of the disease. After diagnosis, vision deteriorates continuously to levels below 20/200 considered legal blindness, as the disease affects mostly the central vision and spares the peripheral vision. Almost all patients with Stargardt's disease will live legally blind during their adult lives, although patients with late onset may retain some visual acuity. Loss of central vision leads to impossibility to perform tasks such as reading, writing, driving or recognizing faces.

Stargardt's disease results from a defective gene, the ABCA4, responsible for the synthesis of an important protein called Rim protein. A normally functioning Rim protein transports vitamin A molecules from the photoreceptors (the molecules sensitive to light) into specialized cells (called RPE), where vitamin A can be recycled to be reused for vision. In Stargardt, the defects in the ABCA4 gene lead to dysfunction of this protein. As a result of the genetic defect, vitamin A transport is affected and vitamin A molecules tend to accumulate in the photoreceptors. This accumulation leads to the formation of toxic pigments (known as "vitamin A dimers") and believed to be partly responsible for vision loss. In a normal individual, this process of accumulating A2E usually takes decades, explaining why age-related macular degeneration (AMD) occurs later in life of normal people, but in patients with Stargardt's disease, the same process takes only a few years explaining the early vision loss.

If the involvement of A2E and other vitamin A dimers in Stargardt is now relatively well understood and if genetic tests can now accurately diagnose the disease, there has been unfortunately little attention paid to Stargardt compared to the more prevalent AMD. An explanation could be that Stargardt is a very rare disease with few patients compared to other diseases, making it less attractive for pharmaceutical companies to develop a treatment for this disease. Rare diseases are also called "orphan diseases" due to this lack of interest from drug developers.

Alkeus Pharmaceuticals is committed to searching and developing cures or treatments for serious ophthalmic conditions, and despite its rareness, a treatment for Stargardt's disease would have a impact on the lives of hundreds of thousands of people worldwide, particularly as patients with Stargardt lose vision during childhood and could benefit the most of a treatment that could slow or stop the progression of vision loss. Such a treatment is generally called a "disease modifying drug", as it may not repair already lost vision but has the potential to alter the course of the disease and slow it down.

In addition, due to certain similarities between Stargardt and dry-AMD, a better understanding of Stargardt's disease could undoubtedly contribute to better understanding and treating of dry-AMD, and perhaps help develop a treatment that could save thousands of Stargardt patients from going blind.

Alkeus' lead compound, ALK-001, is an oral compound with a well understood mechanism of action and solid science. Moreover, ALK-001 was specifically designed to treat Stargardt's disease by preventing the formation of vitamin A dimers in the eye. ALK-001 has been cleared by the U.S. Food and Drug Administration (FDA) to start a clinical trial which will help evaluate the investigational drug profile and test its safety and effectiveness in patients with Stargardt's disease. If you have been diagnosed with Stargardt and would like to stay informed of our future clinical studies, please register in confidence by clicking here.

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