SKADIPhase IV An Evaluator-Blind Controlled Parallel-Group Study To Assess Efficacy And Safety Of Skinoren® 15% Gel And Differin® 0,1% Gel For The Treatment And Maintenance Treatment Of Facial Acne Vulgaris And Late-Type Acne In Females

Differin gel, containing adapalene 0.1%, has been used now for several years in the topical treatment of mild to moderate acne. It has comedolytic and anti-inflammatory activities,and is equally effective and less irritant than other topical retinoids. Adapalene has been shown to maintain therapeutic effect achieved after three months of monotherapy for further three months. Furthermore, its effect in maintenance therapy has been shown in several studies after initial combination with topical or systemic antimicrobials. Skinoren 15% gel (azelaic acid) is an alternative treatment affecting several pathogenetic factors of acne, which has potential in maintenance therapy due to its good tolerability and safety and missing contraindications concerning long-term treatment, which allow even use in pregnancy. Azelaic acid (AzA; HOOC-(CH2)7-COOH) is a naturally occurring compound that interferes with acne pathogenesis by virtue of its antikeratinizing, antibacterial, and anti-inflammatory properties. Vehicle-controlled studies have verified that AzA exercises a significant and clinically relevant effect on both non-inflammatory and inflammatory acne lesions. In the treatment of moderate to severe acne, 20 percent AzA cream may be favorably combined with minocycline (90 percent good and excellent results), and may contribute towards reducing recurrences following discontinuation of systemic therapy (maintenance therapy with AzA cream). Particular advantages of AzA therapy include its favorable safety and side effect profile. It is non-teratogenic, is not associated with systemic adverse events or photodynamic reactions, exhibits excellent local tolerability, and does not induce resistance in Propionibacterium acnes. The 15 % azelaic acid gel has recently proven efficacy in a maintenance treatment of papulopustular rosacea after a combination treatment with oral doxycycline. Mild to moderate acne vulgaris is defined as global severity of 2 through 4, according to the Investigator´s Static Global Assessment (ISGA) and Leeds Revised Acne Grading Scale from 2 trough 7.This inclusion criterion corresponds to the clinical grades usually treated with topical anti-acne therapies. The non-treatment group during the maintenance phase helps to demonstrate the efficacy of Skinoren 15% gel in a maintenance treatment, thereby corroborating the necessity for maintenance therapy reflecting acne as a chronic disease. Acne lesion counting has been used widely in the evaluation of new acne treatments as a change in facial acne lesions counts over time in an individual patient could reflect a true change. However, lesion counts are more valid in greater patient populations as planned in this study. Therefore, the lesion counts are defined as secondary efficacy criteria except during the maintenance phase for the population treated with azelaic acid. As described before, microcomedones are considered as precursor lesion. Moreover, their counts are constantly reduced during acne treatment and precede the clinical relapse. Therefore, microcomedones counts will be used in this trial as a marker of maintenance of therapeutic effect achieved during initial treatment phase.