How do we measure efficacy of therapy in onychomycosis: Patient, physician, and regulatory perspectives

Abstract

Background: Onychomycosis is a difficult to treat fungal infection of the nail plate. Definitions of treatment outcomes measured in clinical trial settings vary widely, preventing the comparison of data across studies. Objective: To investigate definitions of efficacy measures used in clinical trial settings for the treatment of onychomycosis and discuss the importance of consistent reporting. Methods: We searched Pubmed and Ovid for studies in which oral and topical drugs were used to treat onychomycosis. Results: The majority of clinical trials investigated used mycological and clinical cure to validate efficacy of treatment. Mycological cure was almost exclusively defined as negative potassium hydroxide (KOH) microscopy and negative culture, whereas clinical cure had a variety of definitions ranging from ≥ 50% clinical improvement to 0% nail plate involvement. The majority of efficacies were measured between 48–52 weeks from the onset of treatment. Conclusion: Clinical cure and almost complete cure definitions need to be consistently used across all boards. We have suggested definitions for clinical cure, clinical success and clinical improvement. Finally, efficacy measures should be completed between 78-104 weeks from onset of treatment, if feasible.

Keywords:

• Complete cure
• mycological cure
• clinical cure
• treatment success

Disclosure statement

A. K. Gupta has been a clinical trials investigator for Valeant Canada, Nuvolase, Bristol Meyers Squibb, Eli Lilly, Merck, Novartis, Janssen and Allergan. A. K. Gupta has served as a speaker or consultant for Valeant Canada, Janssen, Novartis, Sandoz, Moberg Pharma, and Bayer. C. Studholme is an employee of Mediprobe Research Inc. which conducts clinical trials under the supervision of AKG.