Two randomized, double-blind, controlled trials of 2219 subjects to compare the combination clindamycin/tretinoin hydrogel with each agent alone and vehicle for the treatment of acne vulgaris

Background: The development of a hydrogel to stabilize and solubilize clindamycin and tretinoin provides a single, once-daily treatment for acne vulgaris. Objective: Our aim was to compare the efficacy and safety of the combination of clindamycin (1%) and tretinoin (0.025%) with each agent alone and vehicle. Methods: Two randomized, double-blind, active drug- and vehicle-controlled 12-week studies evaluated inflammatory and noninflammatory lesion counts and the Investigator's Static Global Assessment in 2219 subjects with acne vulgaris. Results: The combination demonstrated superior efficacy to clindamycin, tretinoin, and vehicle. Combination hydrogel was significantly more effective in reducing inflammatory (P < .005), noninflammatory (P <= .0004), and total (P < .0001) lesion counts than the other treatments and vehicle. The proportion of subjects with clear or almost clear skin on the Investigator's Static Global Assessment was greater with the combination (P < .0007). Limitations: A majority of subjects (82.6%) had grade 2-3 acne vulgaris at baseline; therefore these overall results may not be representative of the response in the subjects (17.4%) with grade 4-5 acne. Conclusion: The combination clindamycin/tretinoin hydrogel was well tolerated and significantly more effective than clindamycin, tretinoin, or vehicle for the treatment of acne vulgaris.