By Lisa Seachrist

Washington Editor

QLT PhotoTherapeutics Inc. filed a registration statement with the Securities and Exchange Commission (SEC) and Canadian authorities for a public offering in the U.S. and all provinces of Canada of 2.25 million shares of common stock.

The offering, which is expected to commence April 9, will in all likelihood raise about $100 million for the Vancouver-based photodynamic therapy specialist whose stock (NASDAQ:QLTI) closed at $42.75 a share Tuesday, down $3.125.

CIBC Oppenheimer Corp./CIBC Wood Gundy Securities Inc. is the lead underwriter for the offering, with BT Alex. Brown, ING Baring Furman Selz LLC, Nesbitt Burns Securities Inc. and Warburg Dillon Read LLC serving as co-managers. QLT has granted the underwriters the option to purchase 337,500 common shares to cover overallotments.

The company said in its prospectus it intends to use the money raised by the offering to continue to develop and commercialize photodynamic therapy for a variety of diseases, ranging from cancer to rheumatoid arthritis. In addition, the company may use the funds to expand into areas outside photodynamic therapy via acquisitions and in-licensing agreements.

The company is currently bound by an SEC-ordered quiet period until a month after the offering is completed and was unable to supply further details on its plans.

QLT¿s photodynamic therapy, which targets diseases associated with rapidly growing tissues, is a two-step process beginning with intravenous administration of a photosensitizing drug, followed by exposure to a dose of light to activate the drug.

The photosensitizing drugs attach themselves to lipoproteins in cells. Because rapidly growing cells have a higher concentration of lipoproteins than normal cells, the drug accumulates in these cells more quickly than in normal cells.

QLT already has regulatory approval for Photofrin in the U.S., Canada, Japan and a number of European countries for palliation of advanced lung and esophageal cancers and the treatment of early esophageal cancer. The company also is developing the drug as a therapy for Barrett¿s esophagus, bladder cancer, gastric cancers, cervical cancer and dysplasia.

In addition to Photofrin, the company is developing Visudyne therapy as a treatment for patients suffering from the ¿wet¿ form of age-related macular degeneration (AMD). As the leading cause of blindness in the U.S., AMD affects approximately 10 percent of the population over age 65, 15 percent of whom suffer from the wet form that causes retinal scarring.

Visudyne is in Phase III studies in the U.S., Canada and Europe as well as in Phase I studies in Japan. The company also has the product in Phase III studies as a treatment for choroidal neovascularization due to pathologic myopia, a condition similar to wet form AMD, which usually affects younger people.

Verteporfin is in early stage clinical development for the treatment of non-melanoma skin cancer, psoriasis, rheumatoid arthritis and psoriatic arthritis. The company also is looking at QLT 0074 in the preclinical setting as a treatment for autoimmune diseases.