Evolution of Acne Assessments and Impact on Acne Medications: An Evolving, Imperfect Paradigm.

Background: Outcomes for success in acne interventional trials include statistically significant differences from baseline between treatment arms in lesion counts (comedonal, inflammatory and/or total) and in thresholds of categorical improvement in investigator global assessments (IGA).
Objectives: We evaluated differences in outcome measures and definition of success in acne trials; and their impact on FDA approval and indications for acne medications.
Methods: Review of acne clinical trial literature, prescribing information and regulatory guidelines for currently approved acne medications in the United States.
Results: Numerous IGA scales exist with variations in specific categorical definitions. There are also differences in definitions of global success. Outcome success may not be accurately translated into corresponding terminology for indications.
Conclusions: Variability in IGA scales and definitions of success confound comparison of trial results for acne treatments. Harmonization and standardization of these factors will facilitate meta-analytics and treatment selection in patient care. Outcome measure success has not consistently been incorporated into acne medication indications.