Advances in Acne Care: Evaluating Adapalene-Clindamycin Gel

Acne is caused by multiple factors, including excess sebum production, imbalances in the skin's microbiome, abnormal keratinization, and inflammation. While combination therapies often work better than single treatments to address these underlying factors, they come with several challenges, such as poor adherence to multi-drug regimens and concerns about antibiotic resistance.

Given these challenges, a recent study investigated the effectiveness and safety of a fixed-dose combination gel containing adapalene 0.1% and clindamycin 1% for treating moderate facial acne. Here’s an in-depth look at the research.

How the Study Was Designed

This large-scale Phase III clinical trial involved 1,617 patients between 12 and 40 years old who had moderate facial acne as classified by the Modified Pillsbury Acne Grading Scale.

Participants were randomly assigned to one of three treatment groups:

• A combination gel with adapalene and clindamycin applied once daily at night
• Adapalene gel applied once daily at night
• Clindamycin gel applied twice daily

The study’s main goals were to measure the percentage reduction in total lesion count after 12 weeks and to assess how many patients achieved at least a two-grade improvement on the Investigator Global Assessment (IGA) scale. Secondary goals included reductions in inflammatory and non-inflammatory lesion counts.

What the Study Found

The results showed that the combination gel was more effective than the single treatments. It reduced total lesion counts by 66.85 percent, compared to 50.82 percent with adapalene alone and 57.61 percent with clindamycin alone. Additionally, 19.28 percent of patients using the combination gel saw at least a two-grade improvement on the IGA scale, compared to 7.74 percent in the adapalene group and 14.77 percent in the clindamycin group.

For inflammatory lesions, the combination gel reduced counts by 73.20 percent, which was higher than the reductions seen with adapalene (54.33 percent) and clindamycin (66.33 percent). Similarly, non-inflammatory lesion reductions were greater with the combination gel (63.04 percent) compared to adapalene (46.93 percent) and clindamycin (53.02 percent).

In terms of safety, the results were similar across the treatment groups. Adverse events occurred in 44.74 percent of the combination gel group, 44.51 percent of the adapalene group, and 38.69 percent of the clindamycin group. Most adverse events were mild or moderate, with dry skin and redness being the most common. It’s also important to note that no serious drug-related side effects were reported.

How the Results Might Impact Acne Patients

Given those results, the fixed-dose combination gel proved to be more effective in reducing acne lesions and improving skin scores than either adapalene or clindamycin monotherapy. Its once-daily application is also more convenient for patients, which could help improve adherence. Additionally, using a lower dose of clindamycin in the combination gel may help reduce the risk of antibiotic resistance while still achieving positive response rates. And so overall, this combination therapy shows promise as a safe and effective option for improving moderate facial acne.

Reference:

Luan C, Yang WL, Yin JW, et al. Efficacy and safety of a fixed-dose combination gel with adapalene 0.1% and clindamycin 1% for the treatment of acne vulgaris (CACTUS): a randomized, controlled, assessor-blind, phase III clinical trial. Dermatol Ther (Heidelb). 2024;14(12):3097-3112. doi:10.1007/s13555-024-01286-x