The Effectiveness of Plecanatide for Treating Constipation and Bloating in Patients Aged 18 to 40 Years With Irritable Bowel Syndrome: Utilization of a New Composite Trisymptom Endpoint.

BACKGROUND AND AIM: Irritable bowel syndrome with constipation (IBS-C) is characterized by multiple sensory symptoms, including abdominal pain, bloating, and bowel habit alterations. Therapeutic response should address all components. This study assesses a new exploratory trisymptom composite efficacy endpoint in an IBS-C population of young adults with bloating treated with plecanatide.

METHODS

Pooled data were analyzed from two phase 3, randomized, double-blind trials. Patients (18-40 years) with IBS-C and baseline bloating (score ≥ 1) received plecanatide 3 mg or placebo for 12 weeks. The composite response definition was simultaneous improvement from baseline in three symptoms (abdominal pain, bloating, and complete spontaneous bowel movements [CSBMs]/week) for ≥ 6 of 12 weeks using several thresholds (≥ 2-point or ≥ 30% or ≥ 40% improvement in abdominal pain and bloating plus an increase of ≥ 1 or ≥ 2 CSBMs in the same week).

RESULTS

Six hundred and five adults were included (plecanatide [n = 313]; placebo [n = 292]). Plecanatide/placebo baseline mean symptom scores were 6.2/6.4 for abdominal pain and 6.4/6.6 for bloating; both had a mean of 0.2 CSBMs/week. Significantly more patients in plecanatide versus placebo groups (p ≤ 0.01 for all comparisons) were trisymptom composite responders by several stringent thresholds, including ≥ 30% improvement in pain and bloating plus ≥ 1 CSBM/week increase (23.3% vs. 13.4%; p = 0.002) and ≥ 30% improvement in pain and bloating plus ≥ 2 CSBMs/week increase (19.5% vs. 8.9%; p < 0.001). Plecanatide was well tolerated.

CONCLUSION

Plecanatide simultaneously and significantly improved combined symptoms of abdominal pain, bloating, and CSBM frequency at varying thresholds. Plecanatide is effective in improving global IBS-C symptoms in individuals with bloating.

TRIAL REGISTRATION: ClinicalTrials.gov identifiers-NCT02387359 and NCT02493452.