Onychomycosis is a fungal infection that involves the nail as well as the skin under and around the nail. It is estimated that onychomycosis affects approximately 32 million individuals in the United States. The prevalence of onychomycosis increases with age, with approximately 18% of individuals over the age of 60 affected. The infection typically involves one or more toenails, although fingernail infections represent about 5% of cases. The most common organisms causing onychomycosis are the dermatophytes, such as Trichophyton rubrum. Less commonly, Candida species and some molds can also infect the nail.
Onychomycosis is a chronic condition, often developing over a period of months or even years. The infected nail can become discolored, thickened and disfigured, and may result in pain when walking. Onychomycosis can also be a significant medical issue for diabetics or other patients with compromised immune systems. In these patients, the infected nail can serve as an entry point for bacterial infection, which can in turn lead to serious complications such as amputation.
Onychomycosis will rarely improve without medical treatment. Due to concerns about possible side effects, limited efficacy and frequent relapse experienced with current therapies, physicians may discourage some patients from undergoing currently available treatments, which include both oral and topical therapies. Terbinafine, the most commonly used oral drug to treat onychomycosis, is limited by significant safety concerns, including liver toxicity and drug-drug interactions. Topical therapies suffer from poor efficacy, with complete cure rates ranging from approximately 5 - 18%, and also poor patient compliance.
Viamet is developing oral VT-1161 for the treatment of onychomycosis. This investigational agent has completed a Phase 2b clinical study in patients diagnosed with onychomycosis of the large toenail. VT-1161 has the potential to be a safe and effective oral treatment for onychomycosis.