Durham-based Viamet Pharmaceuticals has reported positive results from clinical trials of its lead product candidate for the treatment of two common fungal infections.

The orally administered compound, called VT-1161, demonstrated safety and efficacy in two Phase 2b trials, one for the treatment of onychomycosis, a chronic infection in the large toenail, and one for the treatment of recurrent vulvovaginal candidiasis, or yeast infection of the vagina.

The onychomycosis study, called RENOVATE, reported complete cure rates ranging from 32 percent to 55 percent after 48 weeks of treatment, and rates continued to improve through 60 weeks, the company said in a news release.

The current standard-of-care for onychomycosis, terbinafine, has a cure rate of about 31 percent at 48 weeks, but safety concerns including liver toxicity and drug-to-drug interactions limit its use. Topical therapies, while safer, suffer from low cure rates, ranging from 6 to 18 percent.

“Current therapies for onychomycosis are suboptimal with respect to efficacy, safety, dosing convenience and duration of response,” said Viamet CEO Robert Schotzinger, M.D., Ph.D. “VT-1161 has demonstrated a high degree of in vitro potency against the most common fungal pathogens that cause onychomycosis, a favorable oral pharmacokinetic profile, and a favorable safety profile in previous studies.

“The increasing complete cure rates at 60 weeks are encouraging signs that VT-1161 may provide patients with a longer duration of response and therefore lower relapse rates. We believe that these attributes, coupled with the positive efficacy and safety results from our RENOVATE trial, suggest that VT-1161 has the potential to be a best-in-class and effective new treatment option for patients with onychomycosis.”

Onychomycosis, primarily affecting the nail, nail bed and surrounding tissues, is extremely common. About 32 million people in the United States have it.

Viamet’s study of recurrent vulvovaginal candidiasis (RVVC) showed that patients taking VT-1161 had much lower recurrence rates of infection, ranging from 0 to 11 percent, compared with 66 percent of patients taking placebo, through 48 weeks. In the trial, called REVIVE, the compound was very well tolerated with a favorable safety profile, and there was also no evidence of an adverse effect on liver function, the company said.

“VT-1161 has demonstrated a high degree of potency against Candida species, the causative fungal pathogens responsible for RVVC, demonstrating the potential to be a first-in-class treatment option for these patients,” Schotzinger said. “It has shown a robust oral pharmacokinetic profile and maintained a favorable safety profile in previous studies. These very positive results from our REVIVE trial suggest that VT-1161 has the potential to be a first-in-class, highly effective and safe treatment option for patients with RVVC.”

An estimated 5 to 8 percent of U.S. women are affected by RVVC during their child-bearing years, but there are no approved therapies, Schotzinger said.

In October 2016 Viamet received Fast Track and Qualified Infectious Disease Product designations for VT-1161 for RVVC from the U.S. Food and Drug Administration. The designations carry incentives including expedited regulatory review by the FDA and a five-year extension of marketing exclusivity.

VT-1161 blocks the production of ergosterol, an essential component of the fungal cell membrane. In preclinical studies it demonstrated broad-spectrum anti-fungal activity against both dermatophytes and Candida species, including those species that cause onychomycosis and RVVC.

Viamet discovers and develops antifungal therapies based on its Metalloenzyme Inhibitor Design and Synthesis (MIDAS) platform. The company identifies small-molecule inhibitors of key metalloenzymes ─ enzymes containing a metal, such as iron, zinc or copper. The platform yields compounds that promise greater selectivity, fewer side effects and better potency compared to currently available antifungal agents.

In addition to VT-1161, Viamet has compounds in development for the treatment of cryptococcal meningitis, valley fever, and hospital-based, invasive fungal infections.

The company in 2015 won a $1.95 million grant from the Department of Defense to develop a topical antifungal agent for preventing and treating mold infections in soldiers with battlefield wounds.

Viamet was founded in 2005 by entrepreneur and inventor Holden Thorp, a chemistry professor at the University of North Carolina at Chapel Hill who went on to become chancellor of UNC before being named provost of Washington University in St. Louis in 2013.

In October 2014, Viamet closed on $60 million in Series D financing provided by Brandon Point Industries, working with Woodford Investment Management. Other investors in the company include Novartis Venture Fund, Lilly Ventures, Hatteras Venture Partners, Intersouth Partners, Lurie Holdings, Astellas Venture Management, A&B Equity Holdings and Malin.

(C) N.C. Biotechnology Center