Efficacy and Tolerability of a Tretinoin 0.02%, Clindamycin 0.8% and Glycolic Acid 4% Gel in Acne: A Multicenter, Prospective, Pragmatic, Assessor-Blinded, 12-Week Trial on 159 Subjects

Abstract

Background: Topical retinoid and antibacterial agents are commonly used as first-line treatments in mild/moderate acne vulgaris (AV). Adherence to retinoid treatment could be limited by the low local tolerability. Literature data show that up to 15% of patients prematurely stop the treatment with retinoids because of skin irritation. A medical device in gel formulation containing tretinoin (0.02%), glycolic acid (4%) and clindamycin (0.8%) is available. So far, no real-life, prospective data regarding efficacy and tolerability of this gel are available. We performed a prospective, multicenter, pragmatic 12-week, assessor-blinded trial. Primary outcomes were the changes of Total acne lesions (TL) count. Secondary outcomes were the evolution of Global Acne Grading System score (GAGS) e and Noninflammatory (NI-L) and Inflammatory (I-L) lesions count. An additional secondary outcome was also to evaluate the local tolerability of the gel. Materials and methods: In a real-life multicenter trial, 159 subjects with mild/moderate AV of the face were enrolled after their informed consent in a 12-week trial. Subjects were instructed to apply the gel once daily at evening. Baseline GAGS score was calculated, and a baseline picture of the face was also taken. Visits were performed after 6 and 12 weeks. Clinical evaluation and pictures were performed at the same time-points. GAGS score, NI-L and I-L calculation were performed evaluating subjects’ pictures coded in a randomized fashion by an assessor unaware of time-sequence. At week 6 and 12, an Investigator Global Assessment (IGA) score, using a 5-point scale was also calculated. Outcomes evaluation was performed on an Intention-to-treat basis. Results: A total of 134 (84%) subjects concluded the 12-week treatment period. Twenty-five subjects (16%) concluded prematurely the trial due to poor local tolerability. At baseline the total number of TL was 17 ± 10. Active treatment reduced significantly TL to 11 ± 7 after 6 weeks and to 6.3 ± 5 after 12 weeks, representing a -63% reduction in comparison with baseline. The mean ± SD GAGS score at baseline was 17.3 ± 8. GAGS score was reduced significantly to 11.8 ± 4 after 6 weeks and to 6.3 ± 3 at the end of treatment (a -63% reduction). Both NI-L and I-L lesions numbers were significant reduced at week 6 (NI-L: -42%; I-L:-35%) and at week 12 (NI-L:-65%; I-L:-65%). Tolerability was evaluated good/very good in 123 out of 134 subjects (91%). Conclusion: This gel containing tretinoin, glycolic and clindamycin, used as monotherapy in the treatment of mild to moderate acne, has shown to be effective in reducing TL, NI-L, I-L and GAGS score. The local tolerability profile is in line with other topical retinoids products.