QLT Inc. said the US Food and Drug Administration (FDA) has completed its review of QLT USA, Inc.'s labelling supplement (sNDA) for Aczone and has removed the glucose-6-phosphate dehydrogenase (G6PD) screening and blood monitoring requirements.

"We are extremely pleased to report the FDA decision to change the Aczone label as it validates QLT's clinical, regulatory and commercialisation strategy for this product. Management believed in the product and took the necessary steps to address the FDA's needs, ultimately dramatically enhancing the value of Aczone," said Bob Butchofsky, president and chief executive officer, QLT. "Aczone represents an important clinical advance in the treatment of acne and demonstrated safety and efficacy in over 4,000 patients. We can now focus on the divestment of this asset."

The sNDA submitted at the end of May 2007 was primarily based on the phase IV clinical trial completed in 56 safety-evaluable G6PD-deficient patients (see the related press release issued November 7, 2006). This study demonstrated no clinical evidence of haemolytic anaemia in this patient population.

Aczone was originally approved for sale on July 7, 2005. The phase IV clinical trial of the product was performed to meet a post-approval commitment requested by the FDA. The purpose of this study was to gather more information about the safety of Aczone, a prescription topical medicine, in treating patients with acne who have G6PD deficiency. During a six-month period, patients were treated with both Aczone and the Aczone-vehicle (control group) in a cross-over design. Data was analyzed by third party clinical experts in dermatology and haematology who concluded that no clinically meaningful changes in safety-related parameters were observed in the trial.

Aczone is the only acne treatment to harness the potential of dapsone in a topical formulation to provide patients with a convenient and effective therapy. QLT USA owns worldwide marketing rights to Aczone.

Aczone is an aqueous topical gel containing 5 per cent dapsone. Combining dapsone in QLT USA's proprietary Solvent Microparticulate (SMP) gel enables dapsone to be applied topically and safely. In two randomized double-blind, vehicle-controlled clinical studies in 3,000 acne patients, Aczone Gel achieved statistically significant percent reduction in the number of acne lesions and better success rate on the Global Acne Assessment Score. The most common adverse events reported from controlled clinical trials include oiliness/peeling, dryness, and erythema. There were no significant differences in the adverse event rates between Aczone Gel and vehicle control treated patients.