NEW ORLEANS – Naftifine hydrochloride 2% cream, an investigational topical allylamine antifungal, hit all of its primary and secondary end points in a pair of phase III, placebo-controlled clinical trials that were conducted in patients with tinea pedis or tinea cruris.
One of the two randomized, double-blind studies involved 334 patients with tinea cruris at 19 centers who were randomized to 2 weeks of once-daily naftifine 2% cream (NAFT-500) or placebo. The primary study end point (complete cure at week 4) was achieved in 25.3% of patients on the topical antifungal agent, compared with 2.8% on placebo, Dr. Lawrence C. Parish reported at the annual meeting of the American Academy of Dermatology.
Complete cure in both phase III trials was defined as negative mycology results on dermatophyte culture and potassium hydrochloride (KOH) mount, along with the absence of erythema, itching, and scaling.
The tinea pedis study included 353 patients at 15 centers who were randomized 2:1 to 2 weeks of once-daily naftifine 2% cream or placebo. Complete cure was achieved at week 6 in 17.7% of the patients who were assigned to the topical allylamine, compared with 7.1% in the placebo arm, according to Dr. Parish of Jefferson Medical College, Philadelphia.
Tinea pedis is one of the top five reasons for physician visits in the United States, and the second-leading skin infection, the dermatologist noted. Secondary end points in the tinea pedis study included the mycologic cure rate, which was 67.3% in the naftifine 2% arm, compared with 21.4% in controls. Treatment effectiveness was defined by a negative culture and KOH. Scores of 0 or 1 on a 0-4 scale for the symptoms of erythema, scaling, and itching was achieved in 56.5% of the active treatment group and in 20% of controls.
Of patients in the naftifine 2% group, 32% rated themselves as experiencing excellent improvement at 6 weeks, compared with 14% of controls. Among naftifine-treated patients, 7.7% rated themselves as unchanged or worse at 6 weeks, compared with 28.6% of controls.
Naftifine 2% cream was well tolerated. The most common adverse events were application site itching (reported by 3.0% of patients assigned to the topical antifungal and 3.4% on placebo) and application site irritation (1.3% and 2.5%, respectively).
The mycologic cure rate at week 4 in the tinea cruris study was 72% in the naftifine 2% arm and 15.5% with placebo. Treatment effectiveness was attained by 60% of naftifine-treated patients and 9.9% of those on placebo.
In terms of patient satisfaction ratings, 43.5% of subjects in the naftifine 2% cream group characterized themselves as showing excellent improvement, as did 11.1% of controls. None of the patients who received the topical allylamine – but 12.7% of controls – said their condition was worse, compared with baseline.
Dr. Parish disclosed having received research grants from Merz Pharmaceuticals to conduct the two phase III studies.