Study of the Safety and Tolerability of ALTH12 Versus Mesalamine Enema in Subjects With Left-Sided Ulcerative Colitis

This Phase I study will be a closely monitored trial of a small number of subjects to establish, preliminarily, the tolerability and safety of two ALTH12 enema formulations: ALTH12-1:4 and ALTH12-2:4. The study will be conducted in two parts. The first part will be the assessment of the safety and tolerability of a single dose of ALTH12-1:4 or the comparator, mesalamine (4.0g 5-ASA) followed by an assessment of repeated administrations of study drug (ALTH12-1:4 or comparator) for 6 weeks. The second part will be the same assessment for ALTH12-2:4. Three subjects will be enrolled in each cohort: 2 to receive ALTH12 enema therapy and 1 subject to receive comparator enema therapy. A total of up to 9 patients will be enrolled in this study, allowing for up to 3 replacement or additional patients.