SP-304 Dose Ranging Study in Patients With Chronic Idiopathic Constipation

This is a Phase 2a, randomized, double-blind, placebo-controlled, 14-day repeat oral, dose ranging study to determine the safety, PK and PD effects of SP-304 in patients with chronic idiopathic constipation. Patients diagnosed with chronic idiopathic constipation (CIC) will be screened for the anticipated 4 cohorts, to yield 80 randomized patients for enrollment. Four dose cohorts are planned (0.3 mg, 1.0 mg, 3.0mg, and 9.0 mg) with 20 patients per dose cohort \[randomization ratio 3:1 (15 receive SP-304:5 receive placebo)\]. Patients who continue to meet all the entry criteria and complete the pre-treatment bowel movement (BM) diary will receive, in a double-blind, randomized fashion, SP-304 or matching placebo. It is expected that each patient will complete all 14 days of dosing (including making accurate BM diary entries for all 14 days in the treatment period). All patients receiving at least one dose of SP-304 or matching placebo will be considered evaluable for the safety endpoints. If a patient receives at least 5 doses per treatment week (1 dose per day for 7 days) and has completed BM diary entries for those 5 dosing days in each corresponding treatment week, he/she will be considered evaluable.