A Randomized, Double-blind, Pivotal Phase 3 Study of WR 279,396 (Paromomycin + Gentamicin Topical Cream) and Paromomycin Alone Topical Cream for the Treatment of Cutaneous Leishmaniasis in Panama

Subjects will be recruited from three regions in Panama known to be endemic for L panamensis CL. Subjects will be screened over a period up to 28 days for eligibility including medical history, physical examination, leishmaniasis history, vital signs, clinical chemistry, prior medications, and parasitology for confirmation of ulcerative CL. If eligible, subjects will be randomized in a targeted 1:1 ratio (200 subjects per group) using site as a stratification variable to receive either WR 279,396 (15% paromomycin + 0.5% gentamicin topical cream) or Paromomycin Alone (15% paromomycin topical cream) by topical application to CL lesions once daily for 20 days. Efficacy will be assessed by measuring the size of the index lesion ulcer, non-index lesions ulcers, and overall size of other non-ulcerated lesions at baseline (before the start of treatment), and on Study Days 20, 35 ± 2 days, 49 ± 4 days, 63 ± 7 days, 100 ± 14 days, and 168 ± 14 days. A notation will be made if clinical evidence of parasite persistence is observed at the Day 63 and beyond visits including significant erythema and induration when a lesion has otherwise completely re-epithelialized to document any subjects removed from the study early if the investigator judges them to be in need of rescue treatment. A photograph will be taken of all lesions at baseline, Day 20 and each of the follow-up visits. Safety will be assessed by monitoring adverse events (AEs) from the start of treatment until study completion, lesion site reactions during treatment, physical examination of the nasal and oral mucosa for appearance of mucosal leishmaniasis on Days 63 ± 7 days, 100 ± 14 days, and 168 ± 14 days, concomitant medication use for the duration of the study, blood creatinine, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels on Study Day 20. After the sponsor's approval, biochemistry can be repeated in the case of abnormal results and if the causes of these results could not be determined. A repeat pregnancy test on Day 35. Recent infection with leishmaniasis prior to the start of the study may result in the development of lesions that were not present at the start of the study that did not receive treatment. New lesions may be treated at the discretion of the investigator with the topical cream to which the subject was assigned any time during the conduct of the study except that treatment must be completed by the Day 168 visit. If a new lesion is discovered at the final study visit, the subject will be referred to their primary physician for treatment.

Subjects who fail therapy (see definition of failure below) will be taken off study and may be administered rescue therapy at the discretion of the subject's personal physician. If the subject met the criteria for therapy failure but was undergoing treatment for new lesions, the subject can continue in the study (by signing a consent addendum) if the investigator decides it is in the best interest of the subject to do so.