Several properties of VT-1161 suggest that it might be a safer and more effective treatment for onychomycosis of the toenail (also known as toenail fungus) than other oral antifungal medicines.

This study will evaluate the effectiveness and safety of VT-1161 for the treatment of toenail onychomycosis and consists of a screening phase, a 24-week treatment phase in which the patient will take either active drug, placebo or a combination of the 2 (according to random assignment), an initial observational phase of 36 weeks and an additional observational study extension of 9 months.

The additional 9-month observational study extension was added with a protocol amendment and patient participation was optional.

Key Inclusion Criteria:

Distal subungual onychomycosis of the great toenail, affecting at least ≥25 to ≤75% of nail.

Positive culture for dermatophytes and positive KOH.

Nail ≤ 3 mm thick at the distal end.

At least ≥ 2 mm of the proximal end of the great toenail must be free of infection.

Subjects must be able to swallow tablets.

Women of childbearing potential and males must use acceptable birth control methods throughout the study.

Key Exclusion Criteria:

Presence of subungual hematoma or melanonychia.

Presence of dermatophytoma/nail streaks and severe onychorrhexis.

Significant dystrophy or anatomic abnormalities of the great toenail.

Presence of any other infections of the foot.

Evidence of clinically significant major organ disease.

Poorly controlled diabetes mellitus.

Onychomycosis involving more than 8 toe nails.

Recent use of systemic antifungal therapy.

Recent of any topical antifungal nail therapy.

Recent use of systemic corticosteroid therapy.

Recent use of immunosuppressive medication.

History of prolonged QT intervals.

Known human immunodeficiency virus (HIV) infection.

Known significant renal or hepatic impairment.

Known history of intolerance or hypersensitivity to azole antifungal drugs.