New MDM2 Inhibitor Drugs Show Promise Treating Macular Degeneration

MDM2 drug injectionSai Chavala, MD, assistant professor of Ophthalmology and Cell Biology and director of the Laboratory for Retinal Rehabilitation at the University of North Carolina, says a class of drugs known as MDM2 inhibitors, has been successful in tests on mice for both wet and dry macular degeneration.

Macular degeneration is a major cause of vision loss, with millions worldwide affected. The part of the eye that gives us sharp, clear vision — the macula — is destroyed with this disease. Macular degeneration makes it hard to drive, read and do many other everyday activities. Age-related macular degeneration (AMD) affects those over 50.

AMD always starts in its “dry” form, causing blind spots or blurry vision. About 20% of these cases progress, developing the “wet” form. Wet macular degeneration involves abnormal blood vessels that leak blood or other fluid, which causes blindness.

Chavala, the senior author of the study, aims for a longer lasting treatment than is now available. Current treatment, an antibody called anti-VEGF, requires an injection to the eye every four to eight weeks. An injection of the MDM2 inhibitors is only needed every eight weeks. This lowers the cost of treatment and reduces the chance of infection at the injection site.

The anti-VEGF takes aim at the growth factors that create abnormal blood vessels. MDM2 inhibitors target the blood vessels themselves. This causes the abnormal blood vessels to regress, or normalize.

MDM2 works because it activates p53, a protein with the power to decide the life or death of a cell. Activating p53 allowed researchers to begin the process of cell death in the abnormal blood vessels. Using low dose radiation can also activate p53, but researchers contend the MDM2 treatment is better because it doesn’t cause the DNA damage that results from the radiation.
The study was done at the University of North Carolina’s School of Medicine, and published in the Journal of Clinical Investigation.

Treating Wet AMD with Radiation

A new study in London is dedicated to determining the effectiveness of an experimental new treatment for wet macular degeneration.

The new treatment is intended to be an alternative to regular eye injections that some AMD patients receive in an attempt to slow the deterioration of their eyesight.  This procedure involves low levels of radiation (reportedly no more than one would be exposed to during a dental x-ray).  This non-surgical approach involves a 20-minute session during which a robot delivers radiation precisely to where it is needed within the eye.

Source: The Engineer

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