provided more details Monday on tests that suggest an experimental drug may improve vision in some people afflicted with a major eyesight-robbing disease.
Building on preliminary data announced in May, Genentech said its experimental drug Lucentis slows the loss of sight in most people tested after 12 months and produces vision improvement in some patients.
The disease, wet age-related macular degeneration, or wet AMD, damages vision via the growth of extra blood vessels in the eye that leak blood or fluid. The leaking causes pressure on part of the retina, leading to distorted vision and loss of vision. Lucentis acts to stop the growth of these blood vessels.
"These data are very compelling, because, for the first time, we have a potential treatment which has been shown to improve vision in a significant number of patients with wet AMD as opposed to just slowing progression of vision loss," Dr. Joan W. Miller, retina specialist at the Massachusetts Eye and Ear Infirmary, said in a press release issued by Genentech. Miller presented test data at a recent meeting of the American Society of Retina Specialists.
The presentation was being watched because of its potential impact on patients, on Genentech, which hopes to submit an application for the treatment to the Food and Drug Administration later this year, and on
, which has a wet AMD drug on the market.
, Eyetech has been selling its drug Macugen since the beginning of the year. Macugen also stops the growth of unwanted blood vessels in the eye.
According to the FDA, patients treated with Macugen "exhibited a significant decrease in vision loss" in two clinical trials that formed the basis for Eyetech approval application. Both trials tested Macugen for two years. Macugen is injected into the eyeball every six weeks, and Lucentis is injected into the eyeball every four weeks.
Although Eyetech's shares have been slipping since January, the
stock's slide accelerated May 23 when Genentech released preliminary results on Lucentis. Eyetech's stock hasn't recovered.
On Monday, Eyetech's shares were off $1.72, or 13%, to $11.73 in heavy trading. Genentech's stock lost $1.52, or 1.7%, to $88.06 on higher than average trading.
Since Genentech's May announcement, Eyetech has been telling doctors, analysts, journalists and patients that comparing the test results of Lucentis and Macugen is akin to comparing apples and oranges. Eyetech points out that its drug is approved by the FDA, that Macugen's test results cover 24 months vs. 12 months for Lucentis, and that Macugen is approved for treating the three forms of wet AMD, whereas the Lucentis tests focus on two forms.
Eyetech and Pfizer resumed their lobbying Monday. "Macugen has a proven safety profile and has been effective in two pivotal studies conducted over two years, the companies said. "The favorable safety profile of Macugen has been maintained for two years in patients who participated in clinical trials and in tens of thousands of patients who are using the drug."
Genentech presented details of a 12-month clinical trial involving 716 people. Some received Lucentis injected into the eye once a month, and some got a sham injection, in which a doctor prepares and anesthetizes the patient's eye but doesn't perform an injection. The fake injection is the equivalent of a placebo in a clinical trial testing drugs.
Patients were tested on their ability to read letters on an eye chart. Each line on the chart had five letters. After 12 months, the Lucentis patients gained an average of seven letters compared with when they started. The control group patients lost an average of 10.5 letters.
The results show 95% of 478 Lucentis patients lost fewer than 15 letters on the eye chart compared with when they started the test. But only 62% of the 238 patients in the control group lost fewer than 15 letters vs. when they started.
The study also found that 25% (or 59 of 238) of patients treated with 0.3 milligrams of Lucentis and 34% (81 of 240) of patients treated with 0.5 milligrams of Lucentis "improved vision by a gain of 15 letters or more," Genentech said. Among the control group, 5% showed a similar gain.
In addition, the company said nearly 40% of Lucentis-treated patients achieved a visual acuity score of 20/40 or better at 12 months compared with 11% percent in the control group.
"We are very excited that Lucentis has improved vision in patients with wet AMD and look forward to results of a second Phase III trial," said Dr. Hal Barron, Genentech senior vice president of development and chief medical officer. Phase III is the final stage of clinical testing before a drug is submitted for regulatory review.
"The magnitude of the treatment effect in this study suggests that Lucentis could have a major impact on the lives of patients with wet AMD," Barron said.
The clinical trial tested patients with two of the three forms of wet AMD, and Genentech noted that it's working with
on a late-stage clinical trial focusing on the third type of wet AMD, involving 423 patients. Results are expected in the fourth quarter. Genentech will market Lucentis in the U.S., Canada and Mexico. Novartis has the marketing rights in the rest of the world.