Tavaborole

Tavaborole is an oxaborole antifungal.

At therapeutic doses, tavaborole is not expected to prolong QTc to any clinically relevant extent.

Tavaborole undergoes extensive metabolism. Renal excretion is the major route of elimination of the metabolites.

In a clinical pharmacology trial of six healthy adult male volunteers who received a single topical application of 5% ¹⁴C-tavaborole solution, tavaborole conjugates and metabolites were shown to be excreted primarily in the urine.

The pharmacokinetics (PK) of tavaborole was investigated in 24 adult subjects with distal subungual onychomycosis involving at least 4 toenails (including at least 1 great toenail) following a single dose and a 2-week daily topical application of 200 μL of a 5% solution of tavaborole to all ten toenails and 2 mm of skin surrounding each toenail. Steady state was achieved after 14 days of dosing. After a single dose, the mean (± standard deviation) peak concentration (C_max) of tavaborole was 3.5 ± 2.3 ng/mL (n=21 with measurable concentrations, range 0.618–10.2 ng/mL, LLOQ=0.5 ng/mL), and the mean AUC_last ± SD was 44.4 ± 25.5 ng*hr/mL (n=21). After 2 weeks of daily dosing, the mean C_max ± SD was 5.2 ± 3.5 ng/mL (n=24, range 1.5–12.8 ng/mL), and the mean AUC_τ ± SD was 75.8 ± 44.5 ng*hr/mL.

In another study PK of tavaborole was investigated in 22 subjects aged 12 years to less than 17 years with distal subungual onychomycosis involving at least 4 toenails (including at least 1 great toenail with at least 20% involvement) following once daily application of 5% solution of tavaborole to all ten toenails and 2 mm of skin surrounding each toenail for 29 days. On Day 29, the mean ± SD C_max was 5.9 ± 4.9 ng/mL (n=21 with measurable concentrations, range 1.0 –16.4 ng/mL, LLOQ=0.5 ng/mL), and the mean ± SD AUC_0-24 was 76.0 ± 62.5 ng*hr/mL.

Drug Interaction Studies

In Vitro Studies

In vitro studies have shown that tavaborole, at therapeutic concentrations, neither inhibits nor induces cytochrome P450 (CYP450) enzymes.