KAUAI, HAWAII – Two keys to effective topical treatment of onychomycosis are treat it early and address coexisting tinea pedis, according to Theodore Rosen, MD.

A third element in achieving treatment success is to use one of the newer topical agents: efinaconazole (Jublia) or tavaborole (Kerydin). The efficacy of efinaconazole approaches that of terbinafine, the most effective and widely prescribed oral agent, which has a 59% rate of almost complete cure, defined as less than 10% residual abnormal nail with no requirement for mycologic cure.

And while tavaborole isn’t quite as effective, it’s definitely better than previous topical agents, Dr. Rosen said at the Hawaii Dermatology Seminar provided by Global Academy for Medical Education/Skin Disease Education Foundation.

Both of these topicals are well tolerated and feature good nail permeation. They also allow for spread to the lateral nail folds and hyponychium. They even penetrate nail polish, although efinaconazole often causes the polish to lose its spiffy gloss, said Dr. Rosen, professor of dermatology at Baylor College of Medicine, Houston.

To underscore the importance of early treatment and addressing concomitant tinea pedis, he cited published secondary analyses of two identical double-blind, multicenter, 48-week clinical trials totaling 1,655 adults with onychomycosis who were randomized 3:1 to once-daily efinaconazole 10% topical solution or its vehicle.

Treat early

Phoebe Rich, MD, of the Oregon Dermatology and Research Center, Portland, broke down the outcomes according to disease duration, in a study of more than 1,500 patients with onychomycosis. She found that the complete cure rate at 52 weeks dropped off markedly in patients with a history of onychomycosis for 1 year or longer at baseline.

Complete cure – defined as no clinical involvement of the target toenail along with both a negative potassium hydroxide examination and a negative fungal culture at 52 weeks – was achieved in 43% of efinaconazole-treated patients with onychomycosis for less than 1 year. The rate then plunged to 17% in those with a disease duration of 1-5 years and 16% in patients with onychomycosis for more than 5 years. Nevertheless, the topical antifungal was significantly more effective than was the vehicle, across the board, with complete cure rates in the vehicle group of roughly 18%, 5%, and 2%, respectively, in patients with onychomycosis for less than 1 year, 1-5 years, and more than 5 years (J Drugs Dermatol. 2015 Jan;14[1]:58-62).

Tackle coexisting tinea pedis

Podiatrists analyzed the combined efinaconazole outcome data based on whether participants had no coexisting tinea pedis, baseline tinea pedis treated concomitantly with an investigator-approved topical antifungal, or tinea pedis left untreated. They concluded that treatment of coexisting tinea pedis decisively enhanced the efficacy of efinaconazole for onychomycosis.

A total of 21% of study participants had concomitant tinea pedis, and 61% of them were treated for it. At week 52, the onychomycosis complete cure rate was 29% in the efinaconazole group concurrently treated for tinea pedis, compared with just 16% if their tinea pedis was untreated (J Am Podiatr Med Assoc. 2015 Sep;105[5]:407-11).

“If you see tinea pedis, don’t blow it off. Treat it. Otherwise, you’re not getting rid of the fungal reservoir,” Dr. Rosen emphasized.

He noted that two topical agents approved for tinea pedis – naftifine 2% cream or gel and luliconazole 1% cream – are effective as once-daily therapy for 2 weeks, a considerably briefer regimen than with other approved topicals. And short-course therapy spells improved adherence, he added.

In the pivotal trials, naftifine had an effective treatment rate – a clinically useful endpoint defined as a small amount of residual scaling and/or redness but no itching – of 57%, while for luliconazole the rates were 33%-48%.

These two agents also are approved for treatment of tinea corporis and tinea cruris. Naftifine is approved as a once-daily treatment for 2 weeks, while luliconazole is, notably, a 7-day treatment. Luliconazole, in particular, is a relatively expensive drug, Dr. Rosen added, so insurers may require prior failure on clotrimazole.

When to treat onychomycosis topically

The pivotal trials of tavaborole and efinaconazole were conducted in patients with 20%-60% nail involvement. The infection didn’t extend to the matrix, and nail thickness and crumbly subungual debris were modest at baseline.

“There are always potential safety issues – drug interactions, GI disturbance, taste loss, headache, teratogenicity, cardiotoxicity, hepatotoxicity – anytime you put a pill in your mouth. So if you have a patient who’s dedicated enough to use a topical for 48 weeks and it’s a modestly affected nail, think about it,” Dr. Rosen advised.

He reported serving on scientific advisory boards for Aclaris, Anacor, Cipla, and Valeant.

SDEF/Global Academy for Medical Education and this news organization are owned by the same parent company.

bjancin@frontlinemedcom.com

Maximizing topical toenail fungus therapy