Provided is a regimen for therapeutic treatment of inflammatory acne lesions in a subject afflicted with moderate to severe acne. The regimen can include topically applying to said subjects skin, as active ingredients, 0.3% by weight adapalene and 2.5% by weight benzoyl peroxide, combined in a single formula that delivers said active ingredients together to achieve, in a group of such subjects, a decrease of at least about 80% in the number of said subjects having nodules and/or cysts after treatment with said regimen, wherein said percents by weight are relative to the weight of the single formula, and wherein said single formula is applied once or twice daily for a period of about 12 weeks.
