High-dose linaclotide is effective and safe in patients with chronic constipation: A phase III randomized, double-blind, placebo-controlled study with a long-term open-label extension study in Japan

Safety and efficacy of linaclotide in children aged 2-5 years with functional constipation: Phase 2, randomized study

OBJECTIVES

Linaclotide, a guanylate cyclase-C agonist, was recently approved in the United States for the treatment of children 6-17 years of age with functional constipation (FC). This study evaluated the dose-response, safety, and efficacy of 4 weeks of linaclotide compared with placebo in children 2-5 years of age with FC.

METHODS

In this phase 2, randomized, double-blind, placebo-controlled, multidose study, 35 children with FC (based on Rome III criteria) were randomized 3:1 to receive linaclotide (18, 36, or 72 μg, for groups 1, 2, and 3, respectively) and 5:1 to receive linaclotide 9, 18, 36, or 72 μg (group 4), or matching placebo. Key endpoints were the changes from baseline in overall spontaneous bowel movement (SBM) frequency (SBMs/week), stool consistency, and straining, as well as the proportion of days with fecal incontinence during the study intervention period. Adverse events (AEs) were recorded.

RESULTS

Of the randomized patients, 34 (97.1%) completed the treatment period and 33 (94.3%) completed the posttreatment period. Mean change from baseline over the treatment period for three of the four key efficacy endpoints showed greater improvement in the linaclotide 72 μg group versus placebo. A dose-response trend was seen for stool consistency in patients receiving linaclotide. Four patients randomized to linaclotide experienced treatment-emergent AEs, one of which was treatment-related (mild diarrhea). All AEs were mild or moderate and none were severe.

CONCLUSIONS

Linaclotide was well tolerated in this pediatric population and an efficacy trend was seen with linaclotide 72 μg versus placebo.

Efficacy of Polyethylene Glycol Electrolyte Powder Combined With Linaclotide for Colon Cleansing in Patients With Chronic Constipation Undergoing Colonoscopy: A Multicenter, Single-Blinded, Randomized Controlled Trial

INTRODUCTION

Constipation is an independent risk factor for poor bowel preparation. This study aimed to evaluate the bowel cleansing efficacy and safety of polyethylene glycol (PEG) combined with linaclotide (lin) for colonoscopy in patients with chronic constipation (CC).

METHODS

This single-blinded, randomized, controlled, and multicenter study was conducted from July 2021 to December 2022 at 7 hospitals. Patients with CC who underwent colonoscopies were enrolled and randomly assigned to 4 groups with split-PEG regimens: 4L-PEG group, 4L-PEG+1d-Lin group, 3L-PEG+1d-Lin group, and 3L-PEG+3d-Lin group. The primary outcome was rates of adequate bowel preparation, defined as a total BBPS score ≥6 and a score ≥2 for each segment. Secondary outcomes were adverse effects, sleep quality, willingness to repeat the colonoscopy, adenoma detection rate, and polyp detection rate.

RESULTS

Five hundred two patients were enrolled. The rates of adequate bowel preparation (80.0% vs 60.3%, P < 0.001; 84.4% vs 60.3%, P < 0.001) and the total Boston Bowel Preparation Scale (BBPS) scores (6.90 ± 1.28 vs 6.00 ± 1.61, P < 0.001; 7.03 ± 1.24 vs 6.00 ± 1.61, P < 0.01) in the 4L-PEG+1d-Lin group and the 3L-PEG+3d-Lin group were superior to that in the 4L-PEG group. Compared with the 4L-PEG group, the 4L-PEG+1d-Lin group (66.7% vs 81.7%, P = 0.008) and the 3L-PEG+3d-Lin group (75.0% vs 81.7%, P = 0.224) had a lower percentage of mild adverse events. No statistically significant difference in willingness to repeat the colonoscopy, sleep quality, polyp detection rate, or adenoma detection rate was observed among groups.

DISCUSSION

PEG combined with linaclotide might be an effective method for bowel preparation before colonoscopy in patients with CC.

Patient-Reported Outcomes in Disorders of Gut-Brain Interaction

Disorders of gut-brain interaction are characterized by chronic gastrointestinal symptoms in the absence of abnormal endoscopic or radiologic findings or objective biomarkers that can be identified during routine clinical evaluation. The assessment of the symptom pattern and severity, therefore, is the key modality to evaluate the presence, impact, and evolution of these conditions, for both clinical and regulatory purposes. Patient-reported outcomes are structured symptom assessment questionnaires designed to evaluate symptom patterns, quantify severity of symptoms, and evaluate response to treatment at follow-up. This review provides an overview of currently available patient-reported outcomes for evaluating the main disorders of gut-brain interaction, specifically, functional dyspepsia; irritable bowel syndrome; and chronic constipation. It summarizes their content, level of validation for clinical practice and for research, and the regulatory approach to these conditions. Expected future developments and need for further research on patient-reported outcomes for these and other disorders of gut-brain interaction are highlighted.

Nocebo effects and influencing factors in the randomized clinical trials of chronic constipation: A systematic review and meta-analysis

BACKGROUND

Nocebo effects are unavoidable in randomized clinical trials. We aimed to assess the magnitude of nocebo effects and explore the influencing factors in chronic constipation.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases up to July 2022. Randomized, placebo-controlled trials investigating interventions in chronic constipation were included. We conducted a random effects meta-analysis of the proportion of adverse events (AEs) in placebo-treated participants and evaluated the effect of trial characteristics on nocebo effects.

KEY RESULTS

We identified 20,204 studies from the databases, of which 61 were included in the final analysis. The pooled placebo AE rate was 30.41%, and AE-related withdrawal rate was 1.53%. The most commonly reported AEs were headache (5.67%), diarrhea (4.45%), abdominal pain (3.98%), nasopharyngitis (3.39%), nausea (3.36%), and flatulence (2.95%). The placebo AE rate was lower in trials conducted in Asia compared to those in Europe, North America, and international trials. It was also lower in trials diagnosed by Rome III compared to clinician's opinion and Rome II. Additionally, the placebo AE rate was lower in single-center trials compared to multicenter trials, lower in 5-8 weeks therapy compared to 9-12 weeks therapy, lower in participants with FC compared to those with IBS-C and CC, lower in trials with 2 arms compared to 3 arms, and higher in trials with prokinetic drugs compared to secretagogues and laxatives.

CONCLUSIONS & INFERENCES

The placebo AE rate was 30.41% in patients with chronic constipation. Based on our findings, we recommend that researchers take the nocebo effects into consideration when designing and conducting clinical trials and adopt specific measures to mitigate the negative influence of nocebo effects.

Clinical factors associated with stable treatment of chronic constipation in Japanese patients

BACKGROUND/AIMS

Chronic constipation (CC) is one of the most common gastrointestinal disorders in the general population. Although there are many treatment options, achieving a stable treatment for CC remains one of the challenges in clinical practice. This study aimed to evaluate the clinical factors associated with stable treatment for CC in Japanese patients.

METHODS

A retrospective, cross-sectional, and multicenter study was carried out. Patients were eligible for inclusion if they fulfilled the Rome IV criteria for diagnosing CC and had been treated for at least one and a half years. Patients with up to two prescription modifications for CC in one year were defined as the stable treatment group, whereas those with three or more prescription changes were defined as the unstable treatment group. Univariate and multivariate analyses were carried out to identify factors associated with CC.

RESULTS

A total of 114 patients have been recruited. There were 82 patients (77.0%) in the stable treatment group and 32 patients (23.0%) in the unstable treatment group. Based on multivariate likelihood analysis, only using acid-suppressive drugs contributed to stability treatment in CC patients (odds ratio: 2.81, 95% confidence interval: 1.12-7.08, p = 0.03).

CONCLUSION

Administration of acid-suppressive drugs was the only factor related to the stability of CC treatment. Further studies are needed to validate the results as well as clarify the causes.

Comparative profiles of lubiprostone, linaclotide, and elobixibat for chronic constipation: a systematic literature review with meta-analysis and number needed to treat/harm

OBJECTIVE

To comprehensively evaluate the efficacy, safety, patient symptoms, and quality-of-life (QoL) of lubiprostone, linaclotide, and elobixibat as treatment for chronic constipation (CC).

DESIGN

Systematic literature review (SLR) and meta-analysis (MA). Literature searches were conducted on PubMed and Embase using the Ovid platform.

METHODS

SLR including randomized controlled trials (RCTs) and observational studies was conducted to identify the overall efficacy and safety of lubiprostone, linaclotide, and elobixibat. Thereafter, MA was performed using only RCTs. The number needed to treat (NNT) and number needed to harm (NNH) analyses were additionally conducted.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was efficacy regarding change in spontaneous bowel movements. Secondary outcomes included safety, constipation-related symptoms, and QoL.

RESULTS

Twenty-four studies met the inclusion criteria for the SLR: 17 RCTs, 4 observational studies, and 3 single-arm trials. Feasibility assessment for the MA resulted in 14 studies available for safety data analysis, and 8 available for efficacy analysis, respectively. Three drugs showed similar efficacy in the MA and NNT analysis. However, the NNH analysis revealed distinct safety profiles: lubiprostone, linaclotide, and elobixibat were linked to the highest risk of nausea, diarrhea, and abdominal pain, respectively.

CONCLUSION

The current study provides an updated overview of the efficacy, safety, patient symptoms, and QoL of the three drugs with different mechanisms of action for CC treatment.The findings could help physicians adopt an individualized approach for treating patients with CC in clinical practice.

Current Management of Chronic Constipation in Japan

Constipation is a complicated condition. Chronic constipation is diagnosed when constipation occurs for more than 3 months. Chronic constipation is classified using patient symptoms and the pathophysiology. New therapeutic agents to treat chronic constipation have recently been approved in Japan. However, treatments for constipation that is refractory to traditional laxatives have been approved, an algorithm for the treatment of chronic constipation has not yet been developed. The accumulation of knowledge and data is necessary to develop a new algorithm.

Decoding signaling mechanisms: unraveling the targets of guanylate cyclase agonists in cardiovascular and digestive diseases

Soluble guanylate cyclase agonists and guanylate cyclase C agonists are two popular drugs for diseases of the cardiovascular system and digestive systems. The common denominator in these conditions is the potential therapeutic target of guanylate cyclase. Thanks to in-depth explorations of their underlying signaling mechanisms, the targets of these drugs are becoming clearer. This review explains the recent research progress regarding potential drugs in this class by introducing representative drugs and current findings on them.

Treatment of Chronic Constipation using Elobixibat in a Real-World Setting: A Retrospective Cohort Study using an Electronic Medical Records Database in Japan

Background

Chronic constipation is a common condition affecting people of all ages; therefore, the socioeconomic burden of chronic constipation is nonnegligible. Elobixibat (ELO), an ileal bail acid transport inhibitor, was launched in Japan in 2018. However, evidence of its use in diverse populations is limited.

Objectives

This study aimed to evaluate the prescription of ELO, risk factors associated with ELO discontinuation, and the continuation of stimulants or saline laxatives during ELO treatment in a real-world setting using an extensive electronic medical records database that primarily includes data from acute-care hospitals.

Methods

Data of patients prescribed for ELO from April 1, 2018, to March 31, 2022, were extracted from the database. The discontinuation of ELO and stimulant or saline laxatives during ELO treatment was evaluated using the Kaplan-Meier method. The Cox proportional hazards model evaluated risk factors associated with laxative discontinuation.

Results

In total, 11,062 patients were evaluated. The rate of ELO discontinuation within 360 days of initiation was 78.7%. Hospitalized at the ELO initiation, stage 5 chronic kidney disease, and diagnosis of constipation by departments of obstetrics and gynecology or by departments of malignant neoplasm were identified as risk factors for discontinuation. Diagnosis of constipation, diabetes mellitus, Parkinson's disease, and previous laxative treatment was associated with a lower risk of ELO discontinuation. The prescription rate of stimulants and saline laxatives markedly decreased after ELO initiation; furthermore, nearly half of patients who were continuously prescribed ELO discontinued these laxatives within 360 days.

Conclusions

The discontinuation of ELO was associated with various factors and using ELO may be beneficial in the withdrawal of concurrent stimulants and saline laxatives. These findings may help effectively manage chronic constipation.

Myths and misconceptions about childhood constipation

Many widely held beliefs and assumptions concerning childhood constipation continue to interfere with rational management of childhood constipation. Although many still believe that constipation is not a common disease, about 9.5% of the world's children suffer from chronic constipation. Most of these children live in non-Western countries. There are major misconceptions about the etiology of constipation as a significant proportion of clinicians still believe that constipation is caused by some form an organic pathology, whereas in reality, the majority have functional constipation. Contrary to a commonly held belief that children outgrow constipation without long-term problems, there is evidence that constipation leads to significant bowel and psychological consequences and has a major impact on the quality of life which detrimentally affects future health and education. Finally, ineffective management strategies such as increasing fiber and water in the diet, and short duration of treatment owing to the fear that long-term laxative treatment leads to colonic dysfunction, interfere with effective therapeutic strategies.   Conclusions: It is apparent that myths and misconception often lead to wrong assumptions regarding the distribution of the disease, its etiology, pathophysiology, and management leading to ordering incorrect investigations and ineffective therapeutic strategies while spending large sums of public funds unnecessarily. Poorly treated constipation leads to deleterious psychological consequences predisposing children to develop significant psychological damage and bowel dysfunctions. This review aims to challenge these myths about various elements of constipation by exploring the existing literature and encouraging clinicians to have a fresh look at old concepts that could interfere with the well-being of children with constipation. What is Known: • Childhood constipation is a growing problem in the world leading to significant suffering and high healthcare expenditure • Myths and misconceptions lead to poor management strategies causing psychological and bowel damage What is New: • Organic, systemic, and bowel disorders leading to constipation are uncommon, and in the majority, it arises due to deliberate fecal withholding and most investigations ordered by clinicians are not very helpful in the management • Most non-pharmacological interventions are not effective in the day-to-day management of childhood constipation. The use of laxatives is considered to be the first-line management strategy.

Effects of linaclotide in the treatment of chronic constipation and irritable bowel syndrome with constipation: a meta-analysis

OBJECTIVE

Linaclotide is a guanylate cyclase-C (GCC) agonist that is found in intestinal epithelial cells and is used when treating chronic constipation (CC) and irritable bowel syndrome with constipation (IBS-C). Several randomized controlled trials (RCTs) were conducted for evaluating its efficacy and safety.

METHODS

The PubMed, EMBASE, and Cochrane databases and the Web of Science were searched to find multiple RCTs of patients with CC or IBS-C. The Jadad scoring system was used for evaluating each study's methodological quality, and RevMan5.3 was used for meta-analysis. The composite endpoint reaction approved by the FDA, abdominal pain and discomfort relief, symptom improvement, and diarrhea-related adverse reactions were chosen as observation indicators, and relative risk (RR) and 95% confidence interval (CI) were obtained for quantitative and comprehensive evaluation.

RESULTS

Eleven randomized controlled studies were included, consisting of 5 cases of CC and 6 cases of IBS-C. Linaclotide reached the composite endpoint response approved by FDA in the treatment of CC (RR = 3.26, 95% CI: 2.45-4.33), and the composite endpoint response approved by FDA for the treatment of IBS-C (RR = 2.26, 95% CI: 1.86-2.74) was greater than the placebo (both p < 0.00001). The main adverse reactions of linaclotide were gastrointestinal, mostly diarrhea, which was higher than that of the placebo when treating CC (RR = 3.56, 95% CI: 2.76-4.60) and IBS-C (RR = 8.23, 95% CI: 5.69-11.90) (both p < 0.00001).

CONCLUSION

Linaclotide proved to be effective and safe for the treatment of CC and IBS-C compared to the placebo. However, diarrhea is the primary adverse reaction.

A Systematic Review and Network Meta-Analysis on the Efficacy of Medications in the Treatment of Chronic Idiopathic Constipation in Japan

Background

In the 2010s, medications with new mechanisms were introduced in Japan for the treatment of chronic idiopathic constipation (CIC). A few systematic reviews have compared medications' relative efficacy, but the reviews included studies on patients from various races, even though the mechanism of CIC is considered to differ between races. The aim of this study was to use a systematic review and network meta-analysis to compare the relative efficacy of these medications in Japanese patients.

Methods

We conducted a meta-analysis and report it here according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We identified studies by searching MEDLINE (via the PubMed interface) and the Cochrane Library and ICHUSHI databases and included randomized clinical trials that compared medications for CIC with placebo in Japanese adults. Two reviewers independently screened and assessed articles, abstracted data, and assessed the risk of bias. We pooled data by random-effects meta-analyses and also performed a Bayesian network meta-analysis to indirectly compare data.

Results

The present systematic review and meta-analyses included 1460 patients in 6 randomized clinical trials: 2 on linaclotide, 3 on elobixibat, 2 on lubiprostone, and 1 on lactulose. The results of direct comparisons showed that linaclotide, elobixibat, and lubiprostone were superior to placebo in the change of spontaneous bowel movements (SBMs) within 1 week: linaclotide, 1.95 (95% CI, 1.51-2.39); elobixibat, 5.69 (95% CI, 3.31-8.07); and lubiprostone, 2.41 (95% CI, 0.82-4.01). The Bayesian network meta-analysis showed consistent results. Elobixibat 10 mg was ranked first for the increase in SBMs and complete SBMs within 1 week and the time to first SBM. Lubiprostone 48 μg was ranked first for the proportion of patients with SBM within 24 hours.

Conclusion

Our direct and indirect meta-analyses revealed that the new CIC medications available in Japan have equal efficacy but that elobixibat and lubiprostone are highly likely to be more efficacious.

Comparison of the Efficacy and Safety of Different Doses of Linaclotide for Patients with Chronic Constipation: A Meta-Analysis and Bayesian Analysis

BACKGROUND

It is ambiguous whether a higher dose of linaclotide provides higher efficacy for chronic constipation (CC) patients. The meta-analysis aimed to assess the efficacy and safety of linaclotide doses ranging from 62.5 μg to 600 μg for CC patients.

METHODS

A comprehensive search was conducted, and STATA16 software was used for data analysis.

RESULTS

Seven studies with 4,107 patients were eligible. A significantly enhanced number of completely spontaneous bowel movement (CSBM) responders were found in the extremely low-dose group (OR: 2.94; 95% CI: 1.98-4.34; p < 0.001), the low-dose group (OR: 3.24; 95% CI: 2.44-4.31; p < 0.001), the medium-dose group (OR: 3.08; 95% CI: 1.46-6.50; p=0.003), and high-dose group (OR: 4.79; 95% CI: 3.04-7.54; p < 0.001). Bayesian analysis showed the high-dose group obtained the maximum CSBM responder rate (OR: 4.94; 95% credible interval (CrI): 3.22-7.79; probability rank = 0.87) indirectly compared with extremely low-dose, low-dose, and medium-dose groups. However, no significant difference presented in the CSBM responder rate by pairwise comparisons of the different dose groups. Additionally, no more any adverse events occurred in the higher linaclotide dose group (RR: 0.91; 95% CrI: 0.60-1.38) indirectly compared with other dose groups.

CONCLUSIONS

High dose of linaclotide could be more effective and safer for CC patients, which need more trials to confirm in the future.

Positioning of Bristol Stool Form Scale type 3 in constipation treatment satisfaction: A multicenter study in Japan

BACKGROUND AND AIM

Many patients are not satisfied with chronic constipation (CC) treatments. The aim of this study was to identify factors linked to CC treatment satisfaction or dissatisfaction.

METHODS

Our study population included patients who received CC treatment at a clinic or hospital. CC was diagnosed by a physician based on the patient's complaint. Treatment satisfaction was evaluated using the 28th question of the Patient Assessment of Constipation Quality of Life questionnaire.

RESULTS

We conducted this study at 28 facilities. We included 167 patients (mean age 66.7 ± 15.2 years, male:female ratio is 1:3.07). Sixty-eight (40.7%) of patients were satisfied with their constipation treatment. Treatment dissatisfaction of CC was significantly associated with frequency of bowel movement <3/week (odds ratio [OR] = 0.376, 95% confidence interval [CI]: 0.156-0.904, P = 0.029) or Bristol Stool Form Scale (BSFS) type 3 (OR = 0.401, 95% CI: 0.170-0.946, P = 0.037).

CONCLUSIONS

Our study showed that CC patients with BSFS type3 were not satisfied with constipation treatment. In general, BSFS types 3-5 are defined as normal stools. Therefore, BSFS type 3 may be set as a treatment goal even though the patient is not satisfied. The pathophysiology of CC differs by region and patient background. Therefore, parameters used to define successful treatment will be different by patient or region. We should reconsider the positioning of BSFS type 3 to improve treatment satisfaction for CC.

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.

[Efficacy and Safety of Linaclotide in Elderly Patients]

The efficacy and safety of linaclotide in elderly patients are poorly understood. Herein, we aimed to assess the efficacy and safety of linaclotide in elderly patients in real-world setting. We retrospectively enrolled consecutive patients who started linaclotide therapy at Sapporo Medical University Hospital from October 1, 2017 to December 31, 2019. The efficacy and safety of linaclotide were examined in relation to various factors, including age (<65 or ≥65 years) and dose (0.25 or 0.5 mg/d). Fifty-two patients were enrolled, 60% of whom were over 65 years old and 40% were female. Thirty-six patients received a linaclotide dose of 0.25 mg/d. The most common side effect was diarrhea, but there was no difference in the incidence of diarrhea between the elderly (64.5%) and non-elderly patients (42.9%, p=0.130). No significant difference was observed with respect to improvement in constipation in the elderly (83.9%) and non-elderly patients (71.4%, p=0.318). Additionally, the difference in efficacy of linaclotide in patients who received a reduced dose (80.6%) vs. those who received the recommended dose (75.0%) was not statistically significant (p=0.719). Multivariate analysis revealed that age, gender, and dose were not associated with diarrhea induced by linaclotide treatment. However, concurrent treatment with constipation-inducing medications [odds ratio (OR) 5.79, p=0.047] and linaclotide monotherapy (OR 11.1, p=0.040) were both risk factors contributing to diarrhea. Linaclotide is effective and safe for use in elderly patients. The incidence of diarrhea may increase when linaclotide is administered alone or concurrently used with medications that cause constipation.

Oral Pharmacological Activation of Hypothalamic Guanylate Cyclase 2C Receptor Stimulates Brown Fat Thermogenesis to Reduce Body Weight

Linaclotide is a synthetic peptide approved by the FDA for the treatment of constipation-predominant irritable bowel syndrome and chronic constipation. Linaclotide binds and activates the transmembrane receptor guanylate cyclase 2C (Gucy2c). Uroguanylin (UGN) is a 16 amino acid peptide that is mainly secreted by enterochromaffin cells in the duodenum and proximal small intestine. UGN is the endogenous ligand of Gucy2c and decreases body weight in diet-induced obese (DIO) mice via the activation of the thermogenic program in brown adipose tissue. Therefore, we wanted to evaluate whether oral linaclotide could also improve DIO mice metabolic phenotype. In this study, we have demonstrated that DIO mice orally treated with linaclotide exhibited a significant reduction of body weight without modifying food intake. Linaclotide exerts its actions through the central nervous system, and more specifically, via Gucy2c receptors located in the mediobasal hypothalamus, leading to the activation of the sympathetic nervous system to trigger the thermogenic activity of brown fat stimulating energy expenditure. These findings indicate for first time that, in addition to its effects at intestinal level to treat irritable bowel syndrome with constipation and chronic constipation, linaclotide also exerts a beneficial effect in whole body metabolism.

Polyethylene glycol 3350 plus electrolytes for chronic constipation: a 2-week, randomized, double-blind, placebo-controlled study with a 52-week open-label extension

BACKGROUND

Although polyethylene glycol 3350 plus electrolytes (PEG3350 + E) is the most widely used osmotic laxative in Europe, prospective data on its long-term (over 6 months) safety and efficacy are not available to date.

METHODS

Japanese patients with chronic constipation were randomized to receive PEG3350 + E or placebo for 2 weeks orally. Following this, the patients received PEG3350 + E in the 52-week extension study. The starting dose was 13.7 g/day dissolved in 125 mL of water, and dose titration was allowed (upper limit 41.1 g/day) according to the patient's bowel condition. The primary efficacy endpoint was the change from baseline in frequency of spontaneous bowel movements (SBMs) at week 2 in the double-blind study. Secondary endpoints and adverse events were assessed. Safety and efficacy were also assessed in the extension study.

RESULTS

Among 204 patients who provided informed consent, 156 were randomized and included in the full analysis. The frequency of SBMs was significantly higher with PEG3350 + E [least squares mean (LSM) 4.3, 95% confidence interval (CI) 3.6-4.9] compared with placebo (LSM 1.6, 95% CI 1.2-2.1; P < 0.0001). A total of 153 patients entered the extension study; PEG3350 + E led to a sustained improvement in bowel function. The common adverse drug reactions during the entire study period were mild gastrointestinal disorders (abdominal pain 4.5%, diarrhea 3.8%, nausea 3.2%, abdominal distension 2.6%).

CONCLUSIONS

Treatment with PEG3350 + E resolved constipation in the short term, was well tolerated, and led to sustained improvement in bowel function in the long-term treatment of Japanese patients with chronic constipation.

CLINICAL TRIAL REGISTRATION NUMBER

Japic CTI-163167.