Abstract

LX1033 proved to be 5-16x more potent than LX1031 based on in vitro enzyme and cell-based assays. Preclinical in vitro and in vivo studies in rodents demonstrate that LX1033 inhibits 5- HT synthesis to a greater extent than LX1031. LX1031 was previously shown to offer clinical benefit to patients with IBS in 4-week placebo, controlled study. LX1033 has demonstrated a favorable safety profile in preclinical studies and may be a novel therapeutic agent for IBS-diarrhea predominant (IBS-D) and other GI disorders. Enrollment is ongoing in a placebo-controlled, 4-week Phase 2 trial of LX1033 in 360 patients with IBS-D.