Promising drug helps seniors with vision disease

washington» An experimental drug is showing promise against an untreatable eye disease that blinds older adults — and intriguingly, it seems to work in patients who carry a particular gene flaw that fuels the damage to their vision.

Age-related macular degeneration, or AMD, is the leading cause of vision loss among seniors, gradually eroding crucial central vision. There are different forms but more than 5 million people worldwide, and a million in the U.S., have an advanced type of so-called “dry” macular degeneration that has no treatment. First patients may notice blurriness when they look straight ahead. Eventually many develop blank spots, becoming legally blind.

“These are seniors who are entering their golden years and now they’ve lost the ability to read, watch television, see their loved ones,” said Dr. Rahul Khurana, a retina specialist and spokesman for the American Academy of Ophthalmology.

The experimental drug, lampalizumab, aims to slow the destruction of light-sensing cells in the retina, creeping lesions that characterize the stage of dry AMD called “geographic atrophy.” When those cells die, they can’t grow back — the vision loss is irreversible.

In an 18-month study of 129 patients, monthly eye injections of the drug modestly slowed worsening of the disease when compared with patients given dummy shots. What’s exciting for scientists came next, when researchers from drugmaker Genentech Inc. took a closer look at exactly who was being helped.

It turns out that nearly 6 in 10 of the study’s participants carry a gene variation that makes part of the immune system go awry. Those are the only patients who appeared to benefit from the drug. While the study is too small to prove if lampalizumab really helps maintain vision, that’s a bigger difference than the overall results suggested.

Wednesday’s study detected no safety concerns, clearing the way for Genentech and its parent company Roche to open two largescale studies that aim to prove if the drug works. Results are expected later this year.