The purpose of this study is to assess the efficacy, safety and tolerability of HTS-519 Inserts in the treatment of mild to moderate toenail fungus disease of the big toenail.

Open label, single-site

Inclusion Criteria:

• Male and females 18 - 74 years of age inclusive
• Fungal toenail infection of one or both of the large (great) toenails
• The nail infection must be due to a dermatophyte, (mixed infections [dermatophyte and non-dermatophyte] are not allowed)
• Willingness not to have professional pedicures or application of any nail polish product or nail cosmetics to the toenails after the screening visit

Exclusion Criteria:

• History of any significant chronic fungal disease other than onychomycosis or immunocompromised condition
• Any abnormalities of the nail or previous surgery of the toenail that could prevent a normal appearing nail if clearing of infection is achieved
• Significant confounding conditions as assessed by the study doctor
• Participation in any other trial of an investigational drug or device within 30 days or participation in a research study concurrent with this study
• No administration of systemic antifungal medications within 6 months prior to screening visit
• No application of prescription topical antifungal medications for toenail fungus within 3 months or other commercially available topical medications for toenail fungus applied directly to the toenails within 1 month prior to screening visit
• Tinea pedis (athlete's foot) that would require systemic treatment

Other protocol-defined inclusion/exclusion criteria may apply

48 weeks