A case-control comparison of direct healthcare-provider medical costs of chronic idiopathic constipation and irritable bowel syndrome with constipation in a community-based cohort

Healthcare Costs of Irritable Bowel Syndrome and Irritable Bowel Syndrome Subtypes in the United States

INTRODUCTION

Contemporaneous data on healthcare costs of irritable bowel syndrome (IBS) in the United States are lacking. We aimed to estimate all-cause and IBS-specific costs in patients with and without IBS and to compare costs across IBS subtypes.

METHODS

Using Optum's deidentified Clinformatics Data Mart Database, we performed a retrospective cohort analysis of patients with and without IBS using data spanning 2016-2021. Patients with IBS were identified by ICD-10 codes. Controls were randomly selected from Clinformatics Data Mart Database participants. Primary outcomes were total all-cause and IBS-specific healthcare costs. Secondary outcomes were costs of individual services associated with any claim. Costs were compared between IBS and control groups and across IBS subtypes using propensity score weighting. Comorbidities were measured with the Elixhauser Comorbidity Index.

RESULTS

Comparison of 102,887 patients with IBS (77.9% female; mean ± SD age 60.3 ± 18.4 years; 75.8% white) and 102,887 controls demonstrated higher median (interquartile range) total costs per year ( P < 0.001) for patients with IBS ($13,288 [5,307-37,071]) than controls ($5,999 [1,800-19,426]). IBS was associated with increased healthcare utilization and higher median annual costs per patient for all services. Median (interquartile range) annual IBS-specific spending was $1,127 (370-5,544) per patient. Propensity score-weighted analysis across IBS subtypes revealed differences in total all-cause and IBS-specific costs and in costs of individual services. Highest spending was observed in IBS with constipation (all-cause $16,005 [6,384-43,972]; IBS-specific $2,222 [511-7,887]).

DISCUSSION

Individuals with IBS exhibit higher healthcare utilization and incur substantially higher all-cause costs than those without. Care costs differ by IBS subtype.

Prevalence and Burden of Illness of Rome IV Chronic Idiopathic Constipation, Opioid-Induced Constipation, and Opioid-Exacerbated Constipation in the United States

INTRODUCTION

Chronic idiopathic constipation (CIC) and opioid-induced constipation (OIC) are disorders that negatively affect quality of life. We sought to assess the prevalence, symptom severity, and medication use among people with Rome IV CIC, OIC, and opioid-exacerbated constipation (OEC) using a nationally representative data set with nearly 89,000 people in the United States.

METHODS

From May 3, 2020, to June 24, 2020, we recruited a representative sample of people in the United States ≥ 18 years to complete an online national health survey. The survey guided participants through the Rome IV CIC and OIC questionnaires, Patient-Reported Outcome Measurement Information System gastrointestinal scales (percentile 0-100; higher = more severe), and medication questions. Individuals with OEC were identified by asking those with OIC whether they experienced constipation before starting an opioid and whether their symptoms worsened afterward.

RESULTS

Among the 88,607 participants, 5,334 (6.0%) had Rome IV CIC, and 1,548 (1.7%) and 335 (0.4%) had Rome IV OIC and OEC, respectively. When compared with people with CIC (Patient-Reported Outcome Measurement Information System score, 53.9 ± 26.5; reference), those with OIC (62.7 ± 28.0; adjusted P < 0.001) and OEC (61.1 ± 25.8, adjusted P = 0.048) had more severe constipation symptoms. People with OIC (odds ratio 2.72, 95% confidence interval 2.04-3.62) and OEC (odds ratio 3.52, 95% confidence interval 2.22-5.59) were also more likely to be taking a prescription medication for their constipation vs those with CIC.

DISCUSSION

In this nationwide US survey, we found that Rome IV CIC is common (6.0%) while Rome IV OIC (1.7%) and OEC (0.4%) are less prevalent. Individuals with OIC and OEC have a higher burden of illness with respect to symptom severity and prescription constipation medication use.

American Gastroenterological Association-American College of Gastroenterology Clinical Practice Guideline: Pharmacological Management of Chronic Idiopathic Constipation

INTRODUCTION

Chronic idiopathic constipation (CIC) is a common disorder associated with significant impairment in quality of life. This clinical practice guideline, jointly developed by the American Gastroenterological Association and the American College of Gastroenterology, aims to inform clinicians and patients by providing evidence-based practice recommendations for the pharmacological treatment of CIC in adults.

METHODS

The American Gastroenterological Association and the American College of Gastroenterology formed a multidisciplinary guideline panel that conducted systematic reviews of the following agents: fiber, osmotic laxatives (polyethylene glycol, magnesium oxide, lactulose), stimulant laxatives (bisacodyl, sodium picosulfate, senna), secretagogues (lubiprostone, linaclotide, plecanatide), and serotonin type 4 agonist (prucalopride). The panel prioritized clinical questions and outcomes and used the Grading of Recommendations Assessment, Development, and Evaluation framework to assess the certainty of evidence for each intervention. The Evidence to Decision framework was used to develop clinical recommendations based on the balance between the desirable and undesirable effects, patient values, costs, and health equity considerations.

RESULTS

The panel agreed on 10 recommendations for the pharmacological management of CIC in adults. Based on available evidence, the panel made strong recommendations for the use of polyethylene glycol, sodium picosulfate, linaclotide, plecanatide, and prucalopride for CIC in adults. Conditional recommendations were made for the use of fiber, lactulose, senna, magnesium oxide, and lubiprostone.

DISCUSSION

This document provides a comprehensive outline of the various over-the-counter and prescription pharmacological agents available for the treatment of CIC. The guidelines are meant to provide a framework for approaching the management of CIC; clinical providers should engage in shared decision making based on patient preferences as well as medication cost and availability. Limitations and gaps in the evidence are highlighted to help guide future research opportunities and enhance the care of patients with chronic constipation.

Analysis of the impact on efficacy of lubiprostone dose reduction to manage adverse events in the treatment of chronic constipation in Japan

OBJECTIVE

To compare outcomes between two doses of lubiprostone in patients with chronic constipation (CC), to assess whether dose reduction affects efficacy.

METHODS

This open-label exploratory study involved 146 patients with CC treated initially with lubiprostone 24 mcg twice daily for a planned duration of 4 weeks. Patients who experienced adverse events (AEs) had their dose reduced to 12 mcg twice daily (for 4 weeks).

RESULTS

Lubiprostone dose was unchanged in 104 patients and reduced due to AEs in 42 patients. Significant differences in the mean number of bowel movements per week favored the dose-reduced group at Week 1 and end of follow-up. No between-group differences were observed over time for mean number of days per week with bowel movements or mean Bristol Stool Form Scale scores. Symptoms of abdominal bloating, strained defecation, and sensation of incomplete evacuation improved in both groups. Before dose reduction, nausea was reported by 64.3% and diarrhea by 45.2% of patients in the dose-reduced group; after dose reduction, no patients reported nausea and one patient reported diarrhea.

CONCLUSION

Dose reduction of lubiprostone reduced the incidence of AEs, with no compromise to efficacy, and may be a suitable approach for patients who develop AEs during treatment.

Burden of Constipation: Looking Beyond Bowel Movements

Chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C) are associated with significant social and economic burdens. To address these burdens, a deeper understanding of their root causes is required. A discrepancy exists between patients' and healthcare providers' (HCPs) perceptions of constipation symptoms and the impact of symptoms associated with CIC and IBS-C. Compared with the HCPs' perceptions of patients' symptoms, a greater percentage of patients report acceptance and feeling in control of their CIC or IBS-C symptoms. Unfortunately, only one-third of individuals with CIC or IBS-C formally consult an HCP about their constipation. Fewer than half take medications, and these are generally over-the-counter therapies rather than prescription therapies. For those who seek help, only one-fifth feel that their constipation symptoms are well managed. Notable sex and cultural differences exist regarding individuals consulting their HCP about constipation. Many individuals with CIC and IBS-C remain inadequately managed and unduly affected, contributing to the high social and economic burden of these conditions.

Cost of Constipation: A New Look With a Focus on New Medications

GOAL

The study was designed to assess drug costs for constipation therapy and to relate costs to markers of functional status.

BACKGROUND

Secretagogues have been introduced as new agents for the treatment of constipation. Previously published modeling studies suggested that improved productivity lowers the indirect disease burden and balances the higher drug costs.

STUDY

Data were abstracted from the publicly available Medical Expenditure Panel Survey to identify adults with a functional gastrointestinal disorder who received a prescription for laxatives or secretagogues covering >2 days. Demographic data, recorded health care utilization and cost, and markers of functional status were extracted for the years from 2005 to 2017 to determine differences between participants treated with secretagogues or laxatives.

RESULTS

The cohort of 2006 persons was female predominant [67.8%; age: 56.9 (55.8-57.9) years] and spent $92.89 (75.68-110.10) for medications treating constipation. The use of secretagogues (10.3% of the cohort) was the best independent predictor of constipation treatment costs. Using quality of life measures, perceived limitations in activities or work, and absenteeism, there was no difference between participants receiving laxatives and those taking secretagogues.

CONCLUSION

Using survey data designed to be representative of the United States population, the study identified secretagogues as a key cost factor in drug treatment of constipation. The results do not support models suggesting improved role functioning offsets these higher direct expenditures. While prospective comparative studies are needed to more definitively correlate costs with direct or indirect benefits of different agents, limiting the use of more expensive medications to otherwise refractory cases may help to reign in the spiraling health care costs in this country.

Evaluating the Impact of Cost on the Treatment Algorithm for Chronic Idiopathic Constipation: Cost-Effectiveness Analysis

INTRODUCTION

Chronic idiopathic constipation (CIC) is a common and burdensome illness. We performed a cost-effectiveness analysis of the US Food and Drug Administration-approved CIC drugs to evaluate and quantify treatment preferences compared with usual care from insurer and patient perspectives.

METHODS

We evaluated the subset of patients with CIC and documented failure of over-the-counter (OTC) osmotic or bulk-forming laxatives. A RAND/UCLA consensus panel of 8 neurogastroenterologists informed model design. Treatment outcomes and costs were defined using integrated analyses of registered clinical trials and the US Centers for Medicare and Medicaid Services-supported cost databases. Quality-adjusted life years (QALYs) were calculated using health utilities derived from clinical trials. A 12-week time horizon was used.

RESULTS

With continued OTC laxatives, CIC-related costs were $569 from an insurer perspective compared with $3,154 from a patient perspective (considering lost wages and out-of-pocket expenses). CIC prescription drugs increased insurer costs by $618-$1,015 but decreased patient costs by $327-$1,117. Effectiveness of CIC drugs was similar (0.02 QALY gained/12 weeks or ∼7 healthy days gained/year). From an insurer perspective, prescription drugs (linaclotide, prucalopride, and plecanatide) seemed less cost-effective than continued OTC laxatives (incremental cost-effectiveness ratio >$150,000/QALY gained). From a patient perspective, the cost-effective algorithm started with plecanatide, followed by choosing between prucalopride and linaclotide starting at the 145-μg dose (favoring prucalopride among patients whose disease affects their work productivity). The patient perspective was driven by drug tolerability and treatment effects on quality of life.

DISCUSSION

Addressing costs at a policy level has the potential to enable patients and clinicians to move from navigating barriers in treatment access toward truly optimizing treatment choice.

Long-Term Administration of Anthraquinone Rhein on Induction of Constipation in Sprague-Dawley Rats via SCF/c-Kit Signaling Pathways

Background and Study Aims. It has been shown that abuse of laxatives is becoming a serious problem; therefore, a comprehensive understanding of its effect and possible mechanism on colon motility is essential to select effective treatments and avoid their abuse. Herein, we aimed to investigate the long-term stimulation of rhein on induction of constipation in rats and its underlying mechanisms. Materials and Methods. After establishing rat models of constipation, the rats were randomly divided into two equal subgroups and administered daily with normal saline (model control group) or 10 ml/kg PEG4,000 (PEG-treated group). Simultaneously, normal Sprague-Dawley (SD) rats were administered with normal saline (normal group). Physiological and fecal parameters were calculated, and intestinal transmission function was evaluated. After scarification, colonic tissues were freshly prepared for histological localization detected by immunohistochemical analysis and for the expression of stem cell factor (SCF) and c-kit proteins determined by western blot assay. Results. Following the initiation of rhein-induced rat constipation, body weight was lost slightly, the first time of black stool discharge was obviously longer, and the fecal moisture and number of fecal pellets decreased distinctly as compared with normal group. A decreased expression of SCF and c-kit was detected in model control group in comparison with normal group. Notably, compared with model control group, neither the alterations of fecal parameters and intestinal transmission function were effectively restored, nor the expression of SCF and c-kit was markedly elevated after administration of PEG4,000 for 30 d. Conclusion. Long-term stimulation of rhein can develop the constipation via SCF/c-kit signaling pathway, yet the symptoms of constipation and colon power cannot be alleviated or restored by PEG4,000. Collectively, these findings strongly suggest that long-term use of anthraquinone laxatives should be avoided for clinical treatment of constipation.

Perceived Barriers to Treatment in Persons Treated for Functional Gastrointestinal Disease with Constipation

INTRODUCTION

Despite expanding treatment options, patients with functional gastrointestinal disorders (FGID) frequently express concerns about problems with access to care. We hypothesized that health insurance coverage contributes to the perceived problems with care delivery.

METHODS

Using the Medical Expenditure Panel Survey, we examined a cohort of participants defined by the diagnosis code for FGID plus the recorded prescription for laxative therapy. Demographic data, healthcare utilization and cost, insurance coverage, comorbid conditions, and information about provider characteristics were extracted for the years 2005-2015. Age- and sex-matched controls were identified for each year included. Barriers to care were based on responses to questions about inability to receive timely care or medication. Logistic regression was used to identify independent predictors of perceived barriers.

RESULTS

The cohort was female predominant (67.8%; mean age: 58.8 ± 0.33 years) with 15.4% reporting problems with access to care. Limited insurance coverage was most commonly cited by respondents. Consistent with this result, uninsured persons were significantly more likely to report barriers to care, while the type of insurance for those covered did not independently predict access problems. In addition, comorbidity burden and provider-specific factors, such as available contact options or insufficient explanations, correlated with perceived barriers to care delivery.

CONCLUSION

While the study design cannot establish causal links, persons with FGID commonly report access problems, which correlate with lack of health insurance and comorbidities. Providers can influence this perception by offering more flexible office hours and incorporating patient expectations related to treatment explanations and shared decision-making.

Comprehensive assessment of patients with irritable bowel syndrome with constipation and chronic idiopathic constipation using deterministically linked administrative claims and patient-reported data: the Chronic Constipation and IBS-C Treatment and Outcomes Real-World Research Platform (CONTOR)

AIMS

To characterize a US population of patients with irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC) using CONTOR, a real-world longitudinal research platform that deterministically linked administrative claims data with patient-reported outcomes data among patients with these conditions.

METHODS

Patients with IBS-C or CIC were identified using diagnosis and treatment codes from administrative claims. Potential respondents received a mailed survey followed by 12 monthly online follow-up surveys and 2 mailed diaries. Surveys collected symptom severity, treatment use, quality of life, productivity, and condition/treatment history. Comorbidities and healthcare costs/utilization were captured from claims data. Diaries collected symptoms, treatments, and clinical outcomes at baseline and 12 months. Data were linked to create a patient-centric research platform.

RESULTS

Baseline surveys were returned by 2,052 respondents (16.8% response rate) and retention rates throughout the study were high (64.8%-70.8%). Most participants reported burdensome symptoms despite having complex treatment histories that included multiple treatments over many years. More than half (55.3%) were dissatisfied with their treatment regimen; however, a higher proportion of those treated with prescription medications were satisfied.

LIMITATIONS

The study sample may have been biased by patients with difficult-to-treat symptoms as a result of prior authorization processes for IBS-C/CIC prescriptions. Results may not be generalizable to uninsured or older populations because all participants had commercial insurance coverage.

CONCLUSIONS

By combining administrative claims and patient-reported data over time, CONTOR afforded a deeper understanding of the IBS-C/CIC patient experience than could be achieved with 1 data source alone; for example, participants self-reported burdensome symptoms and treatment dissatisfaction despite making few treatment changes, highlighting an opportunity to improve patient management. This patient-centric approach to understanding real-world experience and management of a chronic condition could be leveraged for other conditions in which the patient experience is not adequately captured by standardized data sources.

Is Constipation Associated with Worse Functioning in Adult Women? A Cross-Sectional Study

OBJECTIVE

The aim of this study is to analyze the relationship between intestinal constipation and functioning in adult women living in a municipality in the interior of northeast Brazil.

MATERIALS AND METHODS

This is a cross-sectional study conducted with 195 adult women in the city of Santa Cruz-RN. Constipation was diagnosed using the Rome III criteria. Functioning was measured through WHODAS 2.0. Social conditions, habits and lifestyle were also investigated. Inferential analysis was performed using the chi-squared test and the Mann-Whitney U-test, and the effect size was determined by eta squared (η2). Multivariate analysis was performed using multiple linear regression to analyze the relationship between the WHODAS total score and constipation, being adjusted by covariates with p≤0.20 in the bivariate. A statistical significance level of p<0.05 was considered.

RESULTS

Most of the participants in this study were aged 19 to 39 years (69.7%) and had an income of up to 1 minimum monthly salary (79.5%). WHODAS scores showed that women with constipation had more disability in the cognitive (p <0.001), mobility (p <0.002), self-care (p <0.001), and participation (p <0.001) domains, as well as the total score (p <0.001). After multiple linear regression analysis, the total WHODAS score remained associated with constipation (p <0.001), in which this condition increases the score by nine points.

CONCLUSION

The results of this study show that there is a reduction in functioning associated with the presence of constipation in adult women, mainly affecting the cognition, mobility, self-care and participation domains, in addition to the total score.

The Humanistic and Economic Burden of Chronic Idiopathic Constipation in the USA: A Systematic Literature Review

Background

Chronic idiopathic constipation (CIC) is a functional gastrointestinal disorder with an estimated prevalence of 16% in the USA; however, the humanistic and economic burden of CIC is poorly characterized.

Aim

This systematic literature review aimed to assess the humanistic and economic burden of CIC in adults in the USA.

Methods

Two systematic literature searches of English-language publications on the humanistic and economic burden of CIC in adults in the USA were conducted using electronic databases and other resources. Both searches included the terms "chronic idiopathic constipation" and "functional constipation". Specific terms used in the search on humanistic burden included "quality of life", "SF-36", "SF-12", and "PAC-QOL"; search terms for economic burden included "cost", "resource use", "absenteeism", and "productivity".

Results

Overall, 16 relevant articles were identified. Health-related quality of life (HRQoL) appeared to be reduced in patients with CIC compared with controls and the general US population. Abdominal (r=0.33-0.49), stool (r=0.23-0.33), and rectal symptoms (r=0.53) appeared to be associated with reduced HRQoL. Younger age and female sex were associated with reduced overall HRQoL and greater symptom severity. Direct outpatient costs were higher in patients with CIC than those without CIC (US$6284 vs US$5254). Patients with CIC and abdominal symptoms reported more days of disrupted productivity per month than those without abdominal symptoms (3.2 days vs 1.2 days). The overall prevalence of complementary and alternative medicine use by patients with CIC was similar to that in the general US population.

Conclusion

The reduced HRQoL and increased costs associated with CIC indicate unmet therapeutic need in this disorder. Further research is required to better understand the humanistic and economic burden of CIC in the USA.

Chronic Constipation in the United States: Results From a Population-Based Survey Assessing Healthcare Seeking and Use of Pharmacotherapy

OBJECTIVES

Chronic idiopathic constipation (CIC) is characterized by unsatisfactory defecation and difficult or infrequent stools. CIC affects 9%-20% of adults in the United States, and although prevalent, gaps in knowledge remain regarding CIC healthcare seeking and medication use in the community. We recruited a population-based sample to determine the prevalence and predictors of (i) individuals having discussed their constipation symptoms with a healthcare provider and (ii) the use of constipation therapies.

METHODS

We recruited a representative sample of Americans aged 18 years or older who had experienced constipation. Those who met the Rome IV criteria for irritable bowel syndrome and opioid-induced constipation were excluded. The survey included questions on constipation severity, healthcare seeking, and the use of constipation medications. We used multivariable regression methods to adjust for confounders.

RESULTS

Overall, 4,702 participants had experienced constipation (24.0% met the Rome IV CIC criteria). Among all respondents with previous constipation, 37.6% discussed their symptoms with a clinician (primary care provider 87.6%, gastroenterologist 26.0%, and urgent care/emergency room physician 7.7%). Age, sex, race/ethnicity, marital status, employment status, having a source of usual care, insurance status, comorbidities, locus of control, and constipation severity were associated with seeking care (P < 0.05). Overall, 47.8% of respondents were taking medication to manage their constipation: over-the-counter medication(s) only, 93.5%; prescription medication(s) only, 1.3%; and both over-the-counter medication(s) and prescription medication(s), 5.2%.

DISCUSSION

We found that 3 of 5 Americans with constipation have never discussed their symptoms with a healthcare provider. Furthermore, the use of prescription medications for managing constipation symptoms is low because individuals mainly rely on over-the-counter therapies.

Clinical response to linaclotide at week 4 predicts sustained response in irritable bowel syndrome with constipation and improvements in digestive and extra-digestive symptoms

BACKGROUND

Linaclotide is approved for the treatment of moderate-to-severe irritable bowel syndrome (IBS) with constipation (IBS-C) in adults. This study aimed to assess factors predictive of a clinical response and improvements in non-IBS symptoms with linaclotide treatment in a Spanish patient population.

METHODS

In this open-label phase IIIb study, patients with moderate-to-severe IBS-C received linaclotide 290 μg once daily for 12 weeks. The primary endpoint was clinical response at week 12, defined as >30% reduction in IBS symptom severity score (IBS-SSS) or IBS-SSS <75 plus self-reported response of feeling 'better' or 'much better' versus the baseline. Digestive nonintestinal and extra-digestive symptom scores were assessed. Baseline characteristics and week 4 clinical response were assessed as predictors of week 12 clinical response.

RESULTS

A total of 96 patients were eligible; 91 were female and the mean age was 47.4 years. Mean (SD) baseline IBS-SSS was 371 (72.5). In the intention-to-treat and per-protocol populations, 22.9% and 31.7% were clinical responders at week 4, respectively, and 25.0% and 36.7% were clinical responders at week 12. Digestive nonintestinal and extra-digestive symptom scores were significantly improved at weeks 4 and 12. Baseline characteristic was not associated with week 12 clinical response; however, clinical response at week 4 was predictive of response at week 12 (OR: 6.5; 95%IC: 2.1-19.8). The most common adverse event was diarrhea inclusive of loose or watery stools (35.4%).

CONCLUSIONS

Linaclotide improves IBS-C symptoms, including digestive nonintestinal and extra-digestive symptoms. A clinical response at week 4 may predict response at week 12.

Lubiprostone in the treatment of chronic idiopathic constipation: an update on health-related quality of life and patient-reported outcomes

Chronic idiopathic constipation, if inadequately treated, can be bothersome with a detrimental effect on patients’ quality of life (QOL). This may also result in frequent health care visits, increasing the burden of this ailment’s medical cost. Management strategies, focused on lifestyle changes, include increased exercise, a high-fiber diet, and toilet training. Pharmacologic options include fiber supplementation, laxatives, serotonergic agents, and prosecretory agents such as lubiprostone. In this review, we were able to conclude that lubiprostone, when used for chronic idiopathic constipation, has a significantly beneficial effect on both patients’ symptoms and their QOL. In multiple randomized controlled trials, it has been found to have increased the number of spontaneous bowel movements at different time endpoints. Corresponding improvements were also observed for abdominal bloating, discomfort, stool frequency, and straining symptoms among patients.

Benefit-Risk Assessment of Plecanatide in the Treatment of Chronic Idiopathic Constipation

Plecanatide, a uroguanylin analog, activates the guanylate cyclase C receptors in the epithelial lining of the gastrointestinal tract in a pH-dependent fashion initiating (1) the conversion of intracellular guanosine triphosphate to cyclic guanosine monophosphate, which increases the activity of the cystic fibrosis transmembrane conductance regulator to increase chloride and bicarbonate secretion into the intestinal lumen and (2) a decrease in activity of the sodium-hydrogen ion exchanger. The resulting ionic shifts cause an increase in lumenal fluid to facilitate digestion. Plecanatide has been approved by the FDA for use in chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation. This manuscript is a critical assessment of the therapeutic efficacy and potential risks associated with the use of plecanatide in CIC. The discussion of CIC as a clinical and investigative disorder focuses on the importance of this problem as well and the difficulties involved in clinical management and scholarly investigation of a symptom arising from multiple pathophysiologic mechanisms. Clinical data from studies of recently approved drugs for CIC are utilized to construct a platform for thoughtful understanding of CIC and of how changes in investigation guidelines influence the interpretation of study data and guide symptom management. Plecanatide is a safe and effective medication for the management of adults with CIC.

A randomized controlled and long-term linaclotide study of irritable bowel syndrome with constipation patients in Japan

BACKGROUND

Clinical testing was required to verify the effect of linaclotide 0.5 mg/d in patients with irritable bowel syndrome with constipation (IBS-C) in Japan.

METHODS

This was a randomized, double-blind, placebo-controlled (Part 1) and long-term, open-label extension (Part 2) study of linaclotide at 60 hospitals and clinics in Japan. Patients with IBS-C diagnosed using Rome III criteria (n = 500) were randomly assigned to linaclotide 0.5 mg (n = 249) or placebo (n = 251) for a 12-week treatment period followed by open-label treatment with linaclotide (n = 324) for an additional 40 weeks. The primary endpoints were the responder rate of global improvement of IBS symptoms and complete spontaneous bowel movement (CSBM) during 12 weeks. The secondary endpoints included responder rates of SBM and abdominal pain/discomfort relief.

KEY RESULTS

Part 1: The responder rates for global improvement and for CSBM frequency were significantly higher for linaclotide compared to placebo (P < 0.001). Secondary endpoints including responder rates for SBM and abdominal pain/discomfort relief in the linaclotide group were also significantly greater than those in the placebo group. Part 2: Patients switched from placebo to linaclotide showed similar responder rates for global improvement and CSBM frequency to those in patients who continued to receive linaclotide, supporting sustained efficacy. Diarrhea was seen in 14.5% of patients; all cases were mild or moderate.

CONCLUSIONS AND INFERENCES

This study suggests that a linaclotide dose of 0.5 mg is effective and safe for IBS-C patients in Japan.

Safety and tolerability of plecanatide in patients with chronic idiopathic constipation: long-term evidence from an open-label study

OBJECTIVE

This multi-center, fixed-dose, open-label study evaluated the long-term safety and tolerability of once-daily oral plecanatide for the treatment of adults with chronic idiopathic constipation (CIC).

METHODS

Eligible patients completed a phase 2b or phase 3 double-blind study of plecanatide, or had not previously been treated with plecanatide. Enrolled patients received plecanatide (3 or 6 mg) for up to 72 weeks. Safety and tolerability were assessed by the incidence, nature, and severity of spontaneously reported treatment-emergent adverse events (TEAEs). Patients also completed Patient Global Assessment questionnaires, which included measures of treatment satisfaction and the desire to continue treatment.

RESULTS

There were 2370 patient exposures in this study, with the vast majority (90.5%) receiving treatment with plecanatide 6 mg. At the time of study closure, 1932 (81.5%) had completed or were still receiving study drug. TEAEs were qualitatively and quantitatively similar to those observed in prior double-blind studies. The most common TEAEs were diarrhea (7.1%) and urinary tract infection (2.2%). TEAEs leading to discontinuation occurred in 5.3% of patients, with diarrhea leading to discontinuation in 3.1%. Most TEAEs were mild/moderate in severity and were generally considered not related to plecanatide treatment. At the end of treatment, the median score for treatment satisfaction was 4.0 (quite satisfied), and the median score for treatment continuation was 4.0 (quite likely).

CONCLUSIONS

Long-term treatment of adults with CIC demonstrated that plecanatide was safe and well tolerated, with low TEAE and discontinuation rates. Patients indicated satisfaction and a desire to continue with plecanatide treatment.