Aczone (Dapsone) Data Demonstrates Reduction in Number, Severity of Acne Lesions

QLT Inc. announces data from three clinical studies presented at the American Academy of Dermatology conference in New Orleans demonstrating that the Company's acne product Aczone™ (5% dapsone topical gel) reduces the number and severity of all lesion types in acne patients with no significant safety issues.

In the Phase III efficacy and safety trial reported 496 patients were enrolled. Of those, 330 were treated with 5% dapsone topical gel and 166 with a vehicle control gel. Results from this study demonstrate a significant reduction in the all lesion types (inflammatory, noninflammatory and total lesion counts) in patients using dapsone topical gel compared to the vehicle control group.

Evaluations using a five point static Physicians Global Assessment Scale also showed improvements favoring the dapsone topical gel group. These results are consistent with the two pivotal Phase III trials which will be submitted for publication.

The long-term safety study demonstrates that plasma levels of dapsone remained low throughout the 12-month study. Improvement in acne was seen early in the first month and throughout the study. A separate PK study showed that steady state plasma dapsone levels following topical use are more than 100 fold lower than following a single 100mg oral dapsone dose.

"To date, in eight clinical studies over 4000 patients with acne have been treated with Aczone. The clinical data indicate that Aczone has the potential to become an important new prescription treatment for acne, pending approval by the FDA," said Mike Duncan, President of QLT USA, Inc. Aczone was co-developed by QLT USA, Inc., a wholly owned subsidiary of QLT, and Fujisawa Healthcare Inc., for the treatment of acne vulgaris. A new drug application was filed in the third quarter of 2004 seeking marketing approval from the United States Food and Drug Administration (FDA). A decision is expected from the FDA in the second half of 2005. If approved, Aczone will be marketed in the U.S., Canada and Mexico through an agreement with Fujisawa Healthcare Inc. QLT has retained marketing rights for Europe and elsewhere in the world.

Acne vulgaris is most common in 12- to 17-year-olds and is the most common skin disorder in adolescents. Approximately seven million new cases are diagnosed each year in the U.S. Competing products for the treatment of mild to moderate acne are currently selling between $150M to $200M each per year.

Aczone uses the Company's proprietary Solvent Microparticle (SMP™) delivery system to deliver dapsone, a water-insoluble compound with the anti- inflammatory and anti-microbial properties. Dapsone currently is only commercially available as an oral tablet due to the compound's water insolubility. The SMP system allows localized delivery of this drug.

SOURCE: QLT Inc.