Benefit of Topical Combination Therapy for Acne: Analyzing Effect Size Using Number Needed to Treat

Area of Science:

• Dermatology
• Clinical Trials
• Pharmacology

Background:

• Acne vulgaris treatment trials face challenges with high vehicle response rates and varied outcome measures.
• Number Needed to Treat (NNT) offers a standardized method for comparing topical acne treatments indirectly.
• Lower NNT values indicate greater treatment efficacy, despite not capturing all adverse events.

Purpose of the Study:

• To indirectly compare the efficacy of various combination topical acne treatments.
• To utilize Number Needed to Treat (NNT) analysis for standardized treatment comparison.
• To identify superior combination therapies based on consistent efficacy data.

Main Methods:

• A systematic search identified combination topical acne treatments with pivotal Phase 3 efficacy data.
• Treatments meeting the 2018 FDA definition of success were included in Number Needed to Treat (NNT) analyses.
• Efficacy data from 11 trials involving 13 treatments were analyzed, focusing on 12-week success rates.

Main Results:

• Treatment success rates varied from 26.8% (tretinoin 0.1%/BPO 3%) to 50% (triple-combination clindamycin phosphate 1.2%/adapalene 0.15%/BPO 3.1%).
• The triple-combination gel demonstrated favorable NNTs of 4 and 5.
• Adapalene 0.3%/BPO 2.5% gel had an NNT of 5, while tretinoin/BPO showed a wide NNT range (4-9).

Conclusions:

• Triple-combination clindamycin phosphate/adapalene/BPO gel and adapalene/BPO gel exhibited the most favorable Number Needed to Treat (NNT) values.
• This comparative analysis highlights the superior efficacy of specific combination topical therapies for acne vulgaris.
• The findings support the use of NNT for evaluating and comparing acne treatment effectiveness across different trials.