An innovative light-activated treatment, Visudyne therapy is specifically indicated for the treatment of AMD patients with predominantly classic subfoveal choroidal neovascularization. Medical experts estimate that of the 500,000 new patients who develop wet AMD every year around the world, 40-60 percent will develop predominantly classic lesions during the progression of their disease. It is also estimated that approximately 20,000 Canadians develop the wet form of AMD each year. Patients with this condition lose their ability to read and recognise faces in as little as two months to three years.

"Visudyne therapy is an important advance in the treatment of AMD. Before today, there was little to offer patients. I am now hopeful that we will be able to preserve and even improve, in some cases, the vision of many of these patients," said Dr. Patricia Harvey, Retina Unit, Vision Science Research Program, Toronto Western Division, University Health Network.

The approval is based on the 12-month results of two 24-month, double-masked, placebo-controlled and randomised studies. The studies included 609 patients from 8 countries including Canada. Results, published in the October 1999 issue of The Archives of Ophthalmology, show that 67 per cent of AMD patients with predominantly classic lesions who were treated with Visudyne therapy lost less than three lines of vision on a standard eye chart compared to 39 per cent on placebo.

The two year results from the studies, announced on March 28 and presented in May at the annual international meeting of the Association for Research in Vision and Ophthalmology, demonstrated that the benefits of Visudyne therapy were maintained over two years.

Roughly twice as many patients on Visudyne lost less than three lines of vision compared to those on placebo. Further, 13 per cent of Visudyne treated patients experienced a vision improvement that was maintained out to two years.

Retreatment rates decreased from 3.4 treatments during the first year to 2.1 treatments during the second year and Visudyne's positive safety profile was maintained. The most frequently reported adverse events attributed to the treatment include injection site events and visual disturbances. In over 3,400 treatments, photosensitivity reactions occurred less than 0.6 percent of the time.

There are two forms of age-related macular degeneration. The most common is the so-called "dry" form, which is associated with the appearance of small deposits on the macula called "drusen". The macula is a small area of the eye located in the centre of the retina.

Wet AMD is characterised by the formation of abnormal blood vessels (choroidal neovascularization or CNV). These vessels leak fluid and lead to the formation of scar tissue on the macula. Although wet AMD accounts for approximately 15 per cent of all cases of AMD, it is responsible for 90 per cent of vision loss associated with the disease. Wet AMD evolves rapidly and the majority of patients can go blind within a couple of years of being diagnosed.

"It is very gratifying to offer patients a treatment that will be able to improve the quality of their life. Finally, we have an effective and well-tolerated treatment for our patients. This could not have come at a better time as the incidence of AMD is expected to increase sharply as Canadian baby-boomers age," said Dr. Michael Potter, Clinical Assistant Professor, University of British Columbia Medical School, Department of Ophthalmology.

Visudyne can be performed in a doctor's office and consists of two stages.
- First, Visudyne is injected intravenously into the patient's arm. It accumulates in higher concentrations in the abnormal vessels in the eye.
- Next, the drug is activated by shining non-thermal laser light into the patient's eye for approximately 90 seconds. Once activated, Visudyne causes a reduction of growth of the abnormal blood vessels and a corresponding reduction or stabilisation of vision loss. Visudyne therapy does not appear to damage normal retina vessels on fluorescein angiography, even after multiple treatments.

Visudyne therapy is being co-developed for ocular conditions by CIBA Vision and QLT Inc. CIBA Vision markets the product worldwide while QLT is responsible for manufacturing the product.

QLT Inc. is based in Vancouver, British Columbia. It is a world leader in the development and commercialisation of proprietary pharmaceutical products for use in photodynamic therapy, an emerging field of medicine utilising light-activated drugs in the treatment of disease.

CIBA Vision Canada is headquartered in Mississauga, Ontario and employs 350 people throughout the country. CIBA Vision Corporation, part of Novartis AG, is a global leader in research, development and manufacturing of optical and ophthalmic products and services.

Visudyne™ is a trademark of Novartis AG.