<qa>  What is the final efficacy assessment used in primary efficacy analyses?Patients will be treated for approximately 28 days and return to the clinic weekly for safety and efficacy assessments. The investigator will stop study treatment if a patient achieves clinical cure by or after the 3rd treatment visit approximately study day 15. After completing treatment, patients will return to the clinic for scheduled follow-up visits or until ulcer closure. The final efficacy assessments used in the primary efficacy analyses will be obtained at the first follow-up visit approximately 10 days after treatment is stopped. The remaining follow-up visits will occur at approximately 30, 60 and 90 days after treatment is stopped when patients will be assessed for ulcer closure and any re-infection. 