110 CUTIS ® THERAPEUTICS FOR THE CLINICIAN A North American Study of Adapalene– Benzoyl Peroxide Combination Gel in the Treatment of Acne Linda Stein Gold, MD; Jerry Tan, MD; Alma Cruz-Santana, MD; Kim Papp, MD; Yves Poulin, MD; Joel Schlessinger, MD; Judi Gidner, BS; Yin Liu, PhD; Michael Graeber, MD; for Adapalene-BPO Study Group A fixed-dose combination gel with adapalene 0.1% and benzoyl peroxide (BPO) 2.5% recently has been developed for the treatment of acne vulgaris. In this multicenter, randomized, double-blind, parallel-group, active- and vehicle-controlled study conducted at 60 centers in the United States, Puerto Rico, and Canada, we assessed the efficacy and safety of adapalene-BPO combi- nation gel in comparison with adapalene and BPO monotherapies as well as the gel vehicle. Participants with moderate facial acne vul- garis (rated 3 on the 5-point investigator global assessment of acne severity scale) were recruited and randomized to receive once-daily treatment with adapalene-BPO combination gel, adapalene monotherapy, BPO monotherapy, or gel vehicle for 12 weeks. They were assessed for success rate (the percentage of participants with investigator global assessment of acne severity rated clear or almost clear) and percentage change in inflam- matory lesion (IL), noninflammatory lesion (NIL), and total lesion counts. Of the 1668 participants enrolled, 1429 (85.7%) completed the study. At study end point, adapalene-BPO combination gel showed a sig- nificantly higher success rate ( P ≤ .006) and a greater percentage reduction in all acne lesion counts ( P ≤ .017) compared with the other treat- ment groups. A significant early treatment effect of adapalene-BPO combination gel at week 1 compared with adapalene monotherapy and vehi- cle also was observed for all lesion count reduc- tions ( P ,.001). The safety of adapalene-BPO combination gel was comparable with adapalene and BPO monotherapies and vehicle. In a large clinical trial, the adapalene-BPO fixed-dose combination gel has shown superior- ity in efficacy compared with adapalene and BPO monotherapies and vehicle, with an early onset of efficacy and a good safety profile. Cutis. 2009;84:110-116. A cne vulgaris is a chronic disease of the pilose- baceous unit with a multifaceted pathophysi- ology including sebaceous gland hyperplasia with seborrhea, altered follicular growth and differ- entiation, Propionibacterium acnes proliferation, and inflammation and immune response. 1 Fixed-dose combinations are the mainstay of acne treatment. Dr. Stein Gold is from Henry Ford Health Systems, Detroit, Michigan. Dr. Tan is from Windsor Clinical Research Inc, Ontario, Canada. Dr. Cruz-Santana is from Grupo Dermatologico de Carolina, Puerto Rico. Dr. Papp is from K. Papp Clinical Research, Waterloo, Ontario, Canada. Dr. Poulin is from Centre de Recherche Dermatologique du Quebec Metropolitain, Quebec City, Quebec, Canada. Dr. Schlessinger is from Advanced Skin Research Center, Omaha, Nebraska. Mrs. Gidner and Drs. Liu and Graeber are from Galderma R&D Inc, Cranbury, New Jersey. This study was supported by Galderma R&D Inc. Dr. Stein Gold is an advisor, investigator, and speaker for Galderma Laboratories, LP. Dr. Tan is an advisory board member and speaker and has received research grants from Galderma Laboratories, LP. Drs. Cruz-Santana and Papp report no conflict of interest. Dr. Poulin has received research grants from Galderma Laboratories, LP. Dr. Schlessinger is an advisory board member for Galderma Laboratories, LP. Mrs. Gidner and Drs. Liu and Graeber are employees of Galderma Laboratories, LP. ClinicalTrials.gov identifier: NCT00422240. Correspondence: Linda Stein Gold, MD, Henry Ford Health Systems, Dermatology Department, 3031 W Grand Blvd, Ste 800, Detroit, MI 48202 (lstein1@hfhs.org).