A 3-Part Phase 1 Study to Investigate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of DSP-6952 in Healthy Japanese Subjects and Those With ≤3 Spontaneous Bowel Movements per Week

Efficacy and Safety of 5-HT4 Receptor Agonist Minesapride for Irritable Bowel Syndrome with Constipation in a Randomized Controlled Trial

BACKGROUND & AIMS

Treatment options for irritable bowel syndrome with constipation (IBS-C) are limited-new prokinetic drugs are needed. We evaluated the efficacy and safety of minesapride (DSP-6952), a partial agonist with high affinity for 5-HT4 receptors, in patients with IBS-C in Japan.

METHODS

We performed a double-blind phase 2 study of 171 patients with Rome III-defined IBS-C at 33 centers in Japan, from December 2012 through August 2013. Patients were randomly assigned to groups given minesapride (1, 4, 12, or 40 mg) or placebo once daily for 4 weeks. The primary outcome was efficacy, defined as improvement in the weekly frequency of complete spontaneous bowel movements (CSBMs), abdominal symptoms, and IBS-C symptoms (according to the Japanese version of the IBS severity index score). For evaluation of safety, adverse events (AEs) were recorded.

RESULTS

The least squares mean change from baseline in the weekly frequency of CSBMs was greater in all minesapride groups than in the placebo group at week 4 (40 mg vs placebo, P = .040). The abdominal symptoms score improved in minesapride 40 mg group. The overall IBS severity index score decreased from baseline to week 4 in all treatment groups-especially in the 12 mg and 40 mg groups (P = .048 and <.001 vs placebo, respectively). The proportions of patients with treatment-emergent AEs in the pooled minesapride and placebo groups were 55.0% and 60.0%, respectively. The most common treatment-emergent AE was diarrhea (in 42.9% and 37.1% of patients in the pooled minesapride and placebo groups, respectively).

CONCLUSIONS

In a phase 2 trial of patients with IBS-C in Japan, minesapride increased stool frequency (measured by CSBMs), reduced abdominal and overall IBS-C symptoms, and was well tolerated. Japan Pharmaceutical Information Center trial no: JapicCTI-122041.

Pharmacokinetics, safety and metabolite profiling of minesapride, a novel 5-HT4 receptor partial agonist, in healthy elderly and young subjects

Minesapride is a novel 5-hydroxytryptamine 4 (5-HT₄) receptor partial agonist that is expected to show efficacy in patients with irritable bowel syndrome with predominant constipation and functional constipation. An open-label study was conducted to evaluate pharmacokinetics (PK) and safety of minesapride. Japanese subjects, 12 elderly and 12 young, received a single oral dose of minesapride 40 mg/day in the fasted state. Metabolite profiles were also investigated in this clinical study and in an in vitro study using cryopreserved hepatocytes. Clinical results showed that minesapride was rapidly absorbed (C_max: 2302.1 ng/mL in the elderly group, 2117.5 ng/mL in the young group), and the plasma concentration then decreased with half-life of approximately 7 h. There were no notable PK differences between elderly and young groups. No serious adverse events (AEs) were observed. The only AE that occurred in 2 or more subjects was diarrhea. Metabolite profiles in plasma and urine were similar between elderly and young groups. No major metabolites exceeded 10% of unchanged minesapride, and results of the in vitro study suggested that there were no human-specific metabolites. From the viewpoints of PK and metabolite profiling, no dose adjustment of minesapride is warranted in elderly population without renal or hepatic impairment.

Randomised clinical trial: minesapride vs placebo for irritable bowel syndrome with predominant constipation

BACKGROUND

Agonists of 5-hydroxytryptamine 4 receptor are potential agents for irritable bowel syndrome with predominant constipation (IBS-C). However, only tegaserod has been approved for a very limited population in the US.

AIM

To evaluate the efficacy and safety of minesapride in patients with Rome IV defined IBS-C.

METHODS

A double-blind, placebo-controlled, dose-finding study was performed. Overall, 411 patients were randomised to receive minesapride at 10, 20 or 40 mg/d, or placebo for 12 weeks. The primary endpoint was Food and Drug Administration (FDA) composite endpoint (responder: a patient who reported an increase in one or more complete spontaneous bowel movements from baseline and improvement of ≥30% from baseline in weekly average of worst abdominal pain score, both in the same week for ≥6/12 weeks).

RESULTS

The FDA composite responder rate was 13.6% (14/103) in the placebo group, 13.6% (14/103) in the 10 mg group, 19.2% (20/104) in the 20 mg group and 14.9% (15/101) in the 40 mg group, and no dose-response relationship was found. A greater percentage of minesapride 40 mg-treated patients than placebo-treated patients met both responder requirements for ≥9/12 weeks as the stricter composite evaluation (P < 0.05). Furthermore, minesapride 40 mg significantly increased SBM frequency compared with placebo (adjusted P < 0.001 at Week 12). The most common adverse event was mild diarrhoea.

CONCLUSIONS

Minesapride was safe and well-tolerated. Although the primary endpoint was negative, minesapride 40 mg is likely to improve the stricter composite endpoint and SBM frequency. Japan Pharmaceutical Information Center Number: Japic CTI-163459.