Contributed by Tom Harrison| 24 May, 2005  01:51 GMT
A clinical trial of Genentech's investigational drug Lucentis (ranibizumab) showed it was effective in maintaining or restoring vision in patients with wet age-related macular degeneration (AMD), the company announced today.
Approximately 95 percent of patients maintained or improved vision (defined as a loss of less than 15 letters in visual acuity) at one year when treated with Lucentis injections compared to approximately 62 percent of those treated in the control arm (p < 0.0001).
Patients treated with Lucentis for 12 months had, on average, a significant improvement in visual acuity compared to their visual acuity at study entry, while the control group demonstrated a substantial decrease in mean visual acuity from baseline to 12 months.
One-year data from the trial will be presented at the 23rd Annual Meeting of the American Society of Retina Specialists (ASRS), July 16 to 20 in Montreal, Canada.
Leading Cause of Blindness in People over 60
AMD is a major cause of painless central visual loss and is the leading cause of blindness for people over the age of 60. The National Eye Institute estimates that there are 1.6 million people with AMD in the United States alone and that this prevalence will grow to 2.95 million by 2020.
AMD occurs in two forms: dry and wet. The dry form is associated with atrophic cell death of the central retina or macula, which is required for fine vision used for activities, such as reading, driving or recognizing faces.
The wet form is caused by growth of abnormal blood vessels -- also known as choroidal neovascularization (CNV), or ocular angiogenesis -- under the macula. These vessels leak fluid and blood and cause scar tissue that destroys the central retina. This results in a deterioration of sight over a period of months to years.
Exceeded Expectations
"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 Hal Barron, M.D., Genentech senior vice president, development and chief medical officer.
A preliminary analysis of the data showed that adverse events were similar to those seen in earlier trials of Lucentis.
Common side effects occurring in the Lucentis arms more frequently than in the control group were mild to moderate and included conjunctival hemorrhage, eye pain and vitreous floaters. Serious ocular adverse events occurring more frequently in Lucentis-treated patients were rare (<1%) and included uveitis and endophthalmitis. There appeared to be no imbalance in serious non-ocular adverse events.
Lucentis is a humanized antibody fragment developed at Genentech and designed to bind and inhibit Vascular Endothelial Growth Factor A (VEGF-A), a protein that is believed to play a critical role in angiogenesis.
Formation of New Blood Vessels
Angiogenesis is the process by which new blood vessels are formed. In 1989, Napoleone Ferrara, M.D., and a team of scientists at Genentech conducted seminal work in the field, which resulted in the identification and cloning of a gene termed Vascular Endothelial Growth Factor (VEGF), now known as VEGF-A.
The VEGF-A protein is believed to play a critical role in angiogenesis and serves as one of the key contributors to physiological or pathological conditions that can stimulate the formation of new blood vessels. The process of angiogenesis is normally regulated throughout development and adult life, and the uncontrolled growth of new blood vessels is an important contributor to a number of pathologic conditions, including wet AMD.
"We are excited that our pioneering work at Genentech in the field of angiogenesis has again translated into a potential new treatment option for patients with such a significant unmet medical need," said Barron. "We look forward to sharing these positive Phase III data with the FDA."
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