Original Research

Evaluation of Gender as a Clinically Relevant Outcome Variable in the Treatment of Onychomycosis With Efinaconazole Topical Solution 10%

Cutis. 2015 September;96(3):197-201

References

1. Scher RK, Coppa LM. Advances in the diagnosis and treatment of onychomycosis. Hosp Med. 1998;34:11-20.

2. Gupta AK, Jain HC, Lynde CW, et al. Prevalence and epidemiology of onychomycosis in patients visiting physicians’ offices: a multicenter Canadian survey of  15,000 patients. J Am Acad Dermatol. 2000;43:244-248.

3. Finch JJ, Warshaw EM. Toenail onychomycosis:  current and future treatment options. Dermatol Ther. 2007;20:31-46.

4. Kumar S, Kimball AB. New antifungal therapies for the treatment of onychomycosis. Expert Opin Investig Drugs. 2009;18:727-734.

5. Elewski BE, Charif MA. Prevalence of onychomycosis  in patients attending a dermatology clinic in northeastern Ohio for other conditions. Arch Dermatol. 1997;133:1172-1173.

6. Araujo AJG, Bastos OMP, Souza MAJ, et al. Occurrence of onychomycosis among patients attended in dermatology offices in the city of Rio de Janeiro, Brazil. An Bras Dermatol. 2003;78:299-308.

7. Pierard G. Onychomycosis and other superficial fungal infections of the foot in the elderly: a Pan-European  Survey. Dermatology. 2001;202:220-224.

8. Drake LA, Scher RK, Smith EB, et al. Effect of onychomycosis on quality of life. J Am Acad Dermatol. 1998;38(5, pt 1):702-704.

9. Kowalczuk-Zieleniec E, Nowicki E, Majkowicz M.  Onychomycosis changes quality of life. J Eur Acad  Dermatol Venereol. 2002;16(suppl 1):248.

10. Katsambas A, Abeck D, Haneke E, et al. The effects of foot disease on quality of life: results of the Achilles  Project. J Eur Acad Dermatol Venereol. 2005;19:191-195.

11. Salgo PL, Daniel CR, Gupta AK, et al. Onychomycosis disease management. Medical Crossfire: Debates, Peer Exchange and Insights in Medicine. 2003;4:1-17.

12. Elewski BE. The effect of toenail onychomycosis on patient quality of life. Int J Dermatol. 1997;36:754-756.

13. Hay RJ. The future of onychomycosis therapy may  involve a combination of approaches. Br J Dermatol. 2001;145:3-8.

14. Whittam LR, Hay RJ. The impact of onychomycosis on quality of life. Clin Exp Dermatol. 1997;22:87-89.

15. Stier DM, Gause D, Joseph WS, et al. Patient satisfaction with oral versus nonoral therapeutic approaches in onychomycosis. J Am Podiatr Med Assoc. 2001;91:521-527.

16. Elewski BE, Rich P, Pollak R, et al. Efinaconazole 10% solution in the treatment of toenail onychomycosis: two phase 3 multicenter, randomized, double-blind studies.  J Am Acad Dermatol. 2013;68:600-608.

17. Tosti A, Elewski BE. Treatment of onychomycosis with efinaconazole 10% topical solution and quality of life.  J Clin Aesthet Dermatol. 2014;7:25-30.

18. Werschler WP, Bondar G, Armstrong D. Assessing treatment outcomes in toenail onychomycosis clinical trials. Am J Clin Dermatol. 2004;5:145-152.

19. Gupta AK. Treatment of dermatophyte toenail onychomycosis in the United States: a pharmacoeconomic analysis. J Am Podiatr Med Assoc. 2002;92:272-286.

20. Sigurgeirsson B. Prognostic factors for cure following treatment of onychomycosis. J Eur Acad Dermatol  Venereol. 2010;24:679-684.

21. Epstein E. How often does oral treatment of toenail onychomycosis produce a disease-free nail? an analysis of published data. Arch Dermatol. 1998;134:1551-1554.

The current analysis suggests that male onychomycosis patients may be more difficult to treat, a finding noted by other investigators, though the reason is not clear.²⁰ It is known that the prevalence of onychomycosis is higher in males,^2,5 but data comparing cure rates by gender is lacking. It has been suggested that men more frequently undergo nail trauma and tend to seek help for more advanced disease.²⁰ Treatment compliance also may be an issue. In our study, mean nail involvement was similar among male and female participants treated with efinaconazole (36.7% and 35.6%, respectively). Treatment compliance  was higher among females compared to males  (93.0% vs 91.1%), with the lowest compliance rates seen in males in the vehicle group (where complete cure rates also were the lowest). The amount of study drug used was greater in males, possibly due to larger toenails, though toenail surface area was not measured. Although there is no evidence to suggest that male toenails grow quicker, as many factors can impact nail growth, they tend to be thicker. Patients with thick toenails may be less likely to achieve complete cure.²⁰ It also is possible that male toenails take longer to grow out fully, and they may require a longer treatment course. The 52-week duration of these studies may not have allowed for full regrowth of the nails, despite mycologic cure. Indeed, continued improvement in cure rates in onychomycosis patients with longer treatment courses have been noted by other investigators.²¹

The current analysis revealed much lower baseline QOL scores in female onychomycosis patients compared to male patients. Given that target nail involvement at baseline was similar across both groups, this finding may be indicative of greater concern about their condition among females, supporting other views that onychomycosis has a greater impact on QOL in female patients. Similar scores reported across genders at week 52 likely reflects the greater efficacy seen in females.

Conclusion

Based on this subgroup analysis, once-daily application of efinaconazole topical solution 10% may provide a useful option in the treatment of mild to moderate onychomycosis, particularly in female patients. The greater improvement in nail condition concomitantly among females translates to higher overall treatment satisfaction.

Acknowledgment—The author thanks Brian Bulley, MSc, of Inergy Limited, Lindfield, West Sussex, United Kingdom, for medical writing  support. Valeant Pharmaceuticals North America, LLC, funded Inergy’s activities pertaining to  the manuscript.