The Efficacy and Safety of Tavaborole, a Novel, Boron-Based Pharmaceutical Agent: Phase 2 Studies Conducted for the Topical Treatment of Toenail Onychomycosis
September 2014 | Volume 13 | Issue 9 | Original Article | 1124 | Copyright © September 2014
Mirna E. Toledo-Bahena MD,a Alicia Bucko DO JD,b Jorge Ocampo-Candiani MD,c Maira E. Herz-Ruelas MD,c
Terry M. Jones MD,d Michael T. Jarratt MD,e Richard A. Pollak DPM MS,f Lee T. Zane MDg
aInstituto Mexicano de Investigación Clínica, Roma Norte, Cuauhtémoc, Distrito Federal, Mexico
bAcademic Dermatology Associates, Albuquerque, NM
cDepartment of Dermatology, University Hospital José Eleuterio González, Universidad Autónoma de Nuevo León (UANL), Monterrey,
dJ&S Studies, Inc., College Station, TX
eDermResearch, Inc., Austin, TX
fEndeavor Clinical Trials, San Antonio, TX
gAnacor Pharmaceuticals, Inc., Palo Alto, CA
METHODS: One double-blind, randomized, vehicle-controlled study (study 1) and two open-label studies (studies 2 and 3) examined the efficacy, safety, and optimal dosing concentration of tavaborole topical solution applied once daily or three times weekly for 180 days at concentrations of 1.0%, 2.5%, 5.0%, or 7.5%. Patient cohort 3 of study 2 received open-label tavaborole 5.0% once daily for 360 days. All three studies assessed day 180 treatment success, defined as complete or partial clinical evidence of clear nail growth plus negative fungal culture.
RESULTS: A total of 336 patients were included in the intent-to-treat (ITT) or modified ITT populations and efficacy analyses across the 3 studies. In study 1, treatment success rates at day 180 were higher with tavaborole 2.5%, 5.0%, and 7.5% vs vehicle (27%, 26%, and 32% vs 14%, respectively; slope P=0.030). In cohort 3 of study 2, 7% of patients achieved treatment success with tavaborole 5.0% at day 360. Negative culture rates at day 180 in study 1 were numerically higher for tavaborole 2.5%, 5.0%, and 7.5% vs vehicle (slope P=0.046). Application-site reactions of general irritation, erythema, scaling, and stinging/burning were most common with tavaborole 7.5%, were generally mild to moderate, and resolved with treatment discontinuation and/or a reduction in dosing frequency. No systemic safety concerns were observed.
CONCLUSION: Tavaborole solution demonstrated favorable efficacy and safety in phase 2 clinical studies. Based on these findings, tavaborole topical solution, 5% was further investigated in larger, more definitive phase 3 studies. Results from these completed phase 3 studies will provide additional evidence regarding the safety and efficacy of tavaborole in the treatment of toenail onychomycosis.
J Drugs Dermatol. 2014;13(9):1124-1132.