The purpose of the study is to evaluate the efficacy of RV4104A ointment versus bifonazole-urea ointment for the complete removal of the clinically infected nail plate area in patients with toenail onychomycosis.

Inclusion Criteria:

• Clinical diagnosis of distal-lateral or lateral subungual onychomycosis of one great toenail (the target nail)
• Target nail plate showing ≥ 12.5% of clinically infected area
• Patient must have at least 2 mm of the proximal end of the target nail free of infection
• Target nail infection due exclusively to a dermatophyte (from both positive direct microscopy examination and positive fungal culture as reported by the central mycological laboratory)

Exclusion Criteria:

• Patient with more than 2 affected toenails
• Patient with psoriasis, lichen planus or other abnormalities that could result in clinically abnormal toenail(s)
• Patient with moccasin-type tinea pedis
• Patient who has received systemic antifungal therapy or topical antifungal nail lacquer within 3 months or any other topical antifungal therapy applied to the feet or toenails within 2 months prior to screening visit