Updated from 4:46 p.m. EDT

Genentech

(DNA)

said Monday that preliminary tests show most patients afflicted by an eyesight-robbing disease were able to maintain or improve their vision with an experimental drug.

If more test results demonstrate that the drug Lucentis can improve vision, Genentech would have a significant advantage over existing treatments for wet age-related macular degeneration, or wet AMD, which causes people to lose their central vision. Drugs on the market can at best preserve vision or halt the progression of the disease toward legal blindness. Wet AMD usually affects people 50 and over.

"These Lucentis data exceeded our expectations because they show, for the first time in a phase III trial, a statistically significant improvement in vision for patients in a disease that has remained chronic and progressive despite current treatment options," said Dr. Hal Barron, Genentech's senior vice president for development and chief medical officer. Phase III tests are the final clinical trials before a company submits a drug application to health regulators.

Genentech said test results involving 716 people show that about 95% of those taking Lucentis "maintained or improved vision" after 12 months of treatment vs. around 62% given a placebo. Lucentis is injected into the eye every four weeks. Detailed results will be unveiled at a medical conference in Montreal in July.

Genetech and

Novartis

(NVS) - Get Report

are conducting two additional phase III tests of Lucentis. Results of a clinical trial in the U.S., Europe and Australia are expected during the fourth quarter. Results of another clinical trial are due during the first half of 2006.

The partnership calls for Genentech to market Lucentis in North America and Novartis to sell the drug in the rest of the world.

Genentech's eye drug applies a technology to inhibit a protein that is believed to play a role in the development of new blood vessels in the eye. As these runaway vessels proliferate, they leak blood or fluid, putting pressure on part of the eye called the macula which governs fine, detailed vision. When the macula bulges, vision becomes distorted, and if the disease attacks both eyes, people can become legally blind.

If Lucentis is approved, it would be the second drug that thwarts the growth of blood vessels by impairing the activity of a protein called vascular endothelial growth factor, or VEGF.

Eyetech Pharmaceuticals

(EYET)

won FDA approval in December for its drug Macugen. Eyetech's marketing partner is

Pfizer

(PFE) - Get Report

. Macugen has been shown to delay and slow the progression of wet AMD; it does not restore sight.

Macugen must be injected into the eye every six weeks. It has been approved for treating all forms of wet AMD. One key issue for Lucentis will be how many types of wet AMD are approved by the FDA. Monday's test results covered two of three subgroups of the disease.

Genentech's announcement, which came after markets closed, sent Eyetech's stock diving in after-hours trading, as it fell $6.43, or 26.7%, to $17.43. Genentech's shares rose $2.63, or 3.4%, to $79.23 in extended trading.

Shares of another player in the macular degeneration market,

QLT

(QLTI)

, dropped 60 cents, or 5.1%, in after-hours trading.

QLT has teamed up with Novartis to make a different type of drug. Although Macugen and Lucentis must be injected directly into the eye, QLT's drug, Visudyne, is injected intravenously. Visudyne chemically sensitizes the eye, which is then exposed to infrared light.

This treatment, called photodynamic therapy, stops blood vessels from leaking, but it doesn't restore sight and it doesn't stop new blood vessels from developing. According to the Visudyne Web site, the number of treatments per patient can vary, but studies show that, on average, patients require 2.7 treatments a year over the course of two years.

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