MONTREAL -- QLT Inc.. announced Monday the sale of its drug Visudyne for $112.5 million to Valeant Pharmaceuticals International Inc.

Visudyne helped QLT become one of Canada's most successful biotechnology firms on the back of the treatment for age-related macular degeneration -- a major cause of blindness in the elderly.

But sales of the drug, which uses a combination of injections and light therapy to treat AMD, plunged after the introduction of Genentech's Lucentis and rising off-label use of cancer treatment Avastin.

Valeant agreed to pay $62.5 million to acquire the U.S. rights to Visudyne, and another $50 million for rights to the non-U.S. royalties.

QLT is also eligible for up to $5 million in contingent payments relating to the development of its laser program in the United States, up to $15 million related to the non-U.S. royalties.

"The board is pleased to have executed on a key strategic objective and completed a transaction that is in the best interests of the company and its shareholders," QLT chairman Jason Aryeh said in a statement.

"We look forward to returning capital to shareholders in the most efficient manner and to maximize the potential of our synthetic oral retinoid program."

QLT shares were up 48 cents at $7.89 on the Toronto Stock Exchange on Monday, while Valeant shares were up 51 cents at $53.86.

Earlier this year, QLT said it would cut 146 of its 214 remaining jobs. It later lowered its revenue forecast for 2012 to between $31 million and $36 million, compared to its original guidance of $35 to $40 million.

Valeant, which has acquired numerous products and companies since it absorbed the former Biovail pharmaceutical business, said Monday that it sees Visudyne as a valuable addition to the company's ophthalmology business.

"Not only will we be able to use Visudyne to better leverage our current ophthalmology sales force with a complementary product to Macugen, we are pleased to add a product that retinal specialists around the county can use as an adjunctive to products like Macugen to improve treatment options," said Michael Pearson, Valeant's chairman and chief executive officer.