Plecanatide Improves Abdominal Bloating and Bowel Symptoms of Irritable Bowel Syndrome with Constipation

BACKGROUND

Bloating is a bothersome symptom in irritable bowel syndrome with constipation (IBS-C).

AIM

To evaluate plecanatide efficacy in patients with IBS-C stratified by bloating intensity.

METHODS

Pooled phase 3 data (2 randomized, controlled IBS-C trials) from adults treated with plecanatide 3 mg or placebo for 12 weeks were analyzed. Patients were stratified post-hoc by baseline bloating severity (11-point scale: mild [≤ 5] and moderate-to-severe [> 5]). Assessments included change from baseline in bloating, abdominal pain, and complete spontaneous bowel movement (CSBM) frequency. Abdominal pain and bloating composite responders were defined as patients with ≥ 30% improvement from baseline in both bloating and abdominal pain at Week 12.

RESULTS

At baseline, 1104/1436 patients with IBS-C (76.9%) reported moderate-to-severe bloating. In the moderate-to-severe bloating subgroup, plecanatide significantly reduced bloating severity versus placebo (least-squares mean change [LSMC]: - 1.7 vs - 1.3; P = 0.002), reduced abdominal pain (- 1.7 vs - 1.3; P = 0.006), and increased CSBM frequency (1.4 vs 0.8; P < 0.0001). In the mild bloating subgroup, significant improvements were observed with plecanatide versus placebo for abdominal pain (LSMC: - 1.3 vs - 1.0; P = 0.046) and CSBM frequency (2.0 vs 1.2; P = 0.003) but not bloating (- 0.9 vs - 0.8; P = 0.28). A significantly greater percentage of patients were abdominal pain and bloating composite responders with plecanatide versus placebo (moderate-to-severe bloating: 33.6% vs 26.8% [P = 0.02]; mild bloating: 38.4% vs 27.2% [P = 0.03]).

CONCLUSION

Plecanatide treatment improved IBS-C abdominal and bowel symptoms, including in those who present with moderate-to-severe bloating.

Optimizing the Management Algorithm for Adults With Functional Constipation Failing a Fiber/Laxative Trial in General Gastroenterology: Cost-Effectiveness and Cost-Minimization Analysis

INTRODUCTION

Anorectal function testing is traditionally relegated to subspecialty centers. Yet, it is an office-based procedure that appears capable of triaging care for the many patients with Rome IV functional constipation that fail empiric over-the-counter therapy in general gastroenterology, as an alternative to empirical prescription drugs. We aimed to evaluate cost-effectiveness of routine anorectal function testing in this specific population.

METHODS

We performed a cost-effectiveness analysis from the patient perspective and a cost-minimization analysis from the insurer perspective to compare 3 strategies: (i) empiric prescription drugs followed by pelvic floor physical therapy (PFPT) for drug failure, (ii) empiric PFPT followed by prescription drugs for PFPT failure, or (iii) care directed by up-front anorectal function testing. Model inputs were derived from systematic reviews of prospective clinical trials, national cost data sets, and observational cohort studies of the impact of chronic constipation on health outcomes, healthcare costs, and work productivity.

RESULTS

The most cost-effective strategy was upfront anorectal function testing to triage patients to appropriate therapy, in which the subset of patients without anal hypocontractility on anorectal manometry and with a balloon expulsion time of at least 6.5 seconds would be referred to PFPT. In sensitivity analysis, empiric PFPT was more cost effective than empiric prescription drugs except for situations in which the primary goal of treatment was to increase bowel movement frequency. If adopted, gastroenterologists would refer ∼17 patients per year to PFPT, supporting feasibility.

DISCUSSION

Anorectal function testing seems to be an emergent technology to optimize cost-effective outcomes, overcoming testing costs by phenotyping care.

Perceptions, Definitions, and Therapeutic Interventions for Occasional Constipation: A Rome Working Group Consensus Document

BACKGROUND & AIMS

Functional constipation is the most common of the disorders of gut-brain interaction, affecting approximately 12% of the world population. Although classically considered a chronic condition, many individuals experience shorter yet repetitive bouts of constipation representing a different clinical entity. There has been increased interest in this latter disorder, which has recently been classified as occasional constipation. This Rome Foundation working group document reflects the consensus of an international team of specialists who summarized currently available research to provide a working definition of and treatment algorithm for occasional constipation. The recommendations herein are based on current evidence, accounting for gaps in the literature as well as international variance in definitions and health seeking behaviors for constipation.

METHODS

The committee members reviewed the scientific literature, focusing specifically on occasional constipation, with the understanding that as a new entity, a paucity of data would be available. We used Rome IV research and clinical definitions to establish the framework for our definition of occasional constipation. Where possible, treatment recommendations were determined on the basis of the earliest extractable data from functional constipation studies, focusing on positive results within the first 2 weeks of treatment. We used the Delphi method to create consensus with 100% agreement between the authors.

RESULTS

An evidence-based review of the literature resulted in the definition of occasional constipation as follows: "individuals who experience the presence of at least 1 functional constipation symptom, in the absence of alarm signs or symptoms, occurring at irregular and infrequent intervals, which is bothersome enough to induce a patient to seek medical management." Medical management whether seeking medical care or self-treatment was left to the individual's discretion, and we did not include time anchors because these thresholds require further investigation. Polyethylene glycol and stimulant laxatives are recommended as first-line interventions, whereas magnesium-containing compounds are suggested in individuals failing to respond to these therapies. There are insufficient data to make recommendations for using fiber or stool softeners. Prescription laxatives should be reserved for individuals with chronic constipation.

CONCLUSIONS

Occasional constipation is a unique clinical entity characterized by infrequent but recurrent symptoms. Data are limited because consensus definitions have been lacking. Establishing a standardized definition and therapeutic recommendations provides a framework for future studies focusing on epidemiologic and symptoms-based outcomes. Further studies are needed to confirm and refine these recommendations.

Development and Current State of Digital Therapeutics for Irritable Bowel Syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a common, debilitating disorder characterized by abdominal pain and disordered bowel habits. Current pharmacologic treatments often provide incomplete symptom relief and may be poorly tolerated. Furthermore, alleviation of gastrointestinal symptoms does not always translate into improved quality of life for IBS patients. Current treatment guidelines recommend brain-gut behavior therapy (BGBT) in conjunction with other IBS therapies, and, in randomized controlled trials, BGBT has been shown to improve symptoms, patient satisfaction, functioning, and quality of life. Access to BGBT is limited by lack of adequately trained gastrointestinal psychologists, patient time constraints, and cost. Furthermore, clinician knowledge that BGBT is specific, and different from psychotherapy approaches for common mental health disorders, may limit referrals even where available. This review provides an overview of the pathophysiology of IBS, disease burden, unmet therapeutic needs, evidence base of novel digital therapeutics for IBS, and guidance on the introduction and appropriateness of these interventions for patients.

METHODS

We searched the literature for available published data relating to the use of novel digital therapeutics to provide cognitive behavioral therapy and gut-directed hypnotherapy in the treatment of irritable bowel syndrome.

RESULTS

Clinical trial data support the development and utility of digital therapeutics designed to deliver self-guided cognitive behavioral therapy and hypnotherapy for the treatment of IBS.

CONCLUSIONS

BGBTs are effective, guideline-recommended treatments for IBS. Digital therapeutic devices offer accessible, cost-effective treatment options for delivery of adjunctive BGBT for the treatment of IBS. The decision to recommend digital BGBTs should be guided by careful patient assessment that includes mental health screening and risk assessment.

Abdominal Symptom Improvement During Clinical Trials of Tenapanor in Patients With Irritable Bowel Syndrome With Constipation: A Post Hoc Analysis

OBJECTIVES

This post hoc analysis evaluated the efficacy of tenapanor on abdominal symptoms in patients with irritable bowel syndrome with constipation (IBS-C). Abdominal symptoms assessed included pain, discomfort, bloating, cramping, and fullness.

METHODS

The abdominal symptom data were pooled from 3 randomized controlled trials (NCT01923428, T3MPO-1 [NCT02621892], and T3MPO-2 [NCT02686138]). Weekly scores were calculated for each abdominal symptom, and the Abdominal Score (AS) was derived as the average of weekly scores for abdominal pain, discomfort, and bloating. The overall change from baseline during the 12 weeks was assessed for each symptom weekly score and the AS. The AS 6/12-week and 9/12-week response rates (AS improvement of ≥2 points for ≥6/12- or ≥9/12-week) were also evaluated. The association of weekly AS response status (reduction of ≥30%) with weekly complete spontaneous bowel movement (CSBM) status (=0 and >0) was assessed.

RESULTS

Among 1,372 patients (684 tenapanor [50 mg twice a day] and 688 placebo), the least-squares mean change from baseline in AS was -2.66 for tenapanor vs -2.09 for placebo (P<0.0001). The 6/12-week AS response rate was 44.4% for tenapanor vs 32.4% for placebo (P<0.0001), and for 9/12-week AS, 30.6% for tenapanor vs 20.5% for placebo (P<0.0001). A significant association between weekly CSBM status and weekly AS response status was observed each week (P<0.0001), with a greater proportion achieving an AS reduction in patients with >0 CSBMs in a week.

CONCLUSION

Tenapanor significantly reduced abdominal symptoms in patients with IBS-C, particularly pain, discomfort, and bloating measured by AS, compared with placebo.

Optimizing the Utility of Anorectal Manometry for Diagnosis and Therapy: A Roundtable Review and Recommendations

BACKGROUND & AIMS

Anorectal manometry (ARM) is a comprehensive diagnostic tool for evaluating patients with constipation, fecal incontinence, or anorectal pain; however, it is not widely utilized for reasons that remain unclear. The aim of this roundtable discussion was to critically examine the current clinical practices of ARM and biofeedback therapy by physicians and surgeons in both academic and community settings.

METHODS

Leaders in medical and surgical gastroenterology and physical therapy with interest in anorectal disorders were surveyed regarding practice patterns and utilization of these technologies. Subsequently, a roundtable was held to discuss survey results, explore current diagnostic and therapeutic challenges with these technologies, review the literature, and generate consensus-based recommendations.

RESULTS

ARM identifies key pathophysiological abnormalities such as dyssynergic defecation, anal sphincter weakness, or rectal sensory dysfunction, and is a critical component of biofeedback therapy, an evidence-based treatment for patients with dyssynergic defecation and fecal incontinence. Additionally, ARM has the potential to enhance health-related quality of life and reduce healthcare costs. However, it has significant barriers that include a lack of education and training of healthcare providers regarding the utility and availability of ARM and biofeedback procedures, as well as challenges with condition-specific testing protocols and interpretation. Additional barriers include understanding when to perform, where to refer, and how to use these technologies, and confusion over billing practices.

CONCLUSIONS

Overcoming these challenges with appropriate education, training, collaborative research, and evidence-based guidelines for ARM testing and biofeedback therapy could significantly enhance patient care of anorectal disorders.

Efficacy and Safety of Naloxegol in Patients with Chronic Non-Cancer Pain Who Experience Opioid-Induced Constipation: A Pooled Analysis of Two Global, Randomized Controlled Studies

Objective

This study evaluates the onset, magnitude, and consistency of improvement of opioid-induced constipation (OIC) symptoms with naloxegol treatment.

Methods

This was a pooled analysis of two Phase 3, double-blind, randomized, placebo-controlled studies (KODIAC-04/05, NCT01309841/NCT01323790) in patients with chronic non-cancer pain and OIC treated with naloxegol 25mg or 12.5mg daily. This analysis assessed improvements in response rates, frequency of spontaneous bowel movement (SBM) and complete SBMs (CSBM), OIC constipation symptoms (straining, stool consistency), time to first post-dose SBM and CSBM, and onset of adverse events over the 12-week period.

Subjects

The population of 1337 subjects had a mean age of 52 years and mean duration of opioid use of 3.6 years at baseline. Mean SBM frequency was 1.4/week.

Results

Naloxegol 25mg and 12.5mg demonstrated significantly higher response rates vs placebo (PBO) [41.9% (P < 0.001), 37.8% (P = 0.008), 29.4% respectively]. Rapid (within 1 week) and sustained (over 12 weeks) symptom improvement was significantly greater for naloxegol vs PBO (P < 0.05). Both doses showed statistically significant and clinically meaningful improvements in straining, stool consistency, number of SBMs and CSBMs/wk. Significantly shorter times to first post-dose SBM and CSBM were observed with naloxegol vs PBO (SBM HR: 25mg = 1.90, 12.5mg= 1.60; CSBM HR: 25mg = 1.42, 12.5mg = 1.36; P < 0.001 for each regimen). Adverse events occurred more frequently in the naloxegol 25mg group and were most frequently reported during the first week.

Conclusion

In patients with chronic non-cancer pain, naloxegol 25mg and 12.5mg demonstrated significantly higher response rates and rapid and sustained improvements in OIC symptoms compared with PBO.

Plecanatide Improves Symptoms of Irritable Bowel Syndrome with Constipation: Results of an Integrated Efficacy and Safety Analysis of Two Phase 3 Trials

Purpose

Patients with irritable bowel syndrome with constipation (IBS-C) experience abdominal pain with altered bowel movements. Plecanatide is indicated as IBS-C treatment in adults. This integrated analysis further characterizes plecanatide efficacy and safety in IBS-C.

Patients and Methods

Data pooled from 2 identically designed phase 3 trials included adults with IBS-C randomized to plecanatide 3 mg or 6 mg, or placebo once daily for 12 weeks. A daily diary recorded stool frequency/symptoms, with abdominal pain, bloating, cramping, discomfort, fullness, and straining intensity individually rated. Overall response (primary endpoint) was defined as ≥30% improvement from baseline in average worst abdominal pain severity and increase of ≥1 complete spontaneous bowel movement, during same week (composite), for ≥6 of 12 weeks. Secondary endpoints included sustained response (overall response, plus meeting weekly composite criteria during ≥2 of last 4 treatment weeks) and changes from baseline in individual symptoms. Safety assessments included adverse event monitoring.

Results

Overall, 2176 patients (74.0% female; mean [SD] age, 43.5 [14.1] years) were included in efficacy analyses (plecanatide 3 mg [n = 724], 6 mg [n = 723], placebo [n = 729]). A significantly greater percentage of patients achieved overall response with plecanatide 3 mg (25.6%) and 6 mg (26.7%) versus placebo (16.0%; both P < 0.001 vs placebo). A significantly greater percentage of patients were sustained responders with plecanatide 3 mg (24.3%) and 6 mg (25.6%) versus placebo (15.6%; both P < 0.001 vs placebo). Significant improvements from baseline in abdominal discomfort, abdominal fullness, abdominal pain, bloating, and cramping occurred as early as Week 1 (Week 2 for abdominal pain) with plecanatide and were maintained through Week 12 versus placebo. Diarrhea, the most common adverse event, occurred in 4.3% (3 mg), 4.0% (6 mg) and 1.0% (placebo) of patients, leading to study discontinuation in 1.2%, 1.4%, and 0 patients, respectively.

Conclusion

Plecanatide is safe and effective for treating global and individual IBS-C symptoms.

Differential Diagnosis of Chronic Diarrhea: An Algorithm to Distinguish Irritable Bowel Syndrome With Diarrhea From Other Organic Gastrointestinal Diseases, With Special Focus on Exocrine Pancreatic Insufficiency

Chronic diarrhea, defined as diarrhea persisting for more than 4 weeks, affects up to 5% of the population regardless of patient age, sex, race, or socioeconomic status. The impact on patient health and quality of life is substantial, and diagnosis and management of these patients have significant economic consequences for health care services. The differential diagnosis of chronic diarrhea is broad, with etiologies including infections, endocrinopathies, maldigestive/malabsorptive conditions, and disorders of gut-brain interaction. The considerable overlap of symptoms across this spectrum makes accurate diagnosis problematic and may lead to delays in diagnosis or misdiagnosis. In this narrative review, we consider the differential diagnosis of chronic diarrhea, focusing on irritable bowel syndrome with diarrhea and exocrine pancreatic insufficiency, two conditions that may present similarly but have very different underlying causes and require significantly different management strategies. We outline a 4-step diagnostic strategy and propose a straightforward algorithm to assist in efficiently differentiating irritable bowel syndrome from exocrine pancreatic insufficiency and other causes of chronic diarrhea. We anticipate that these aids will improve diagnostic accuracy, which ultimately should lead to improvements in patients' health-related quality of life and reduce the societal burden on health care services.

Rare, Overlooked, or Underappreciated Causes of Recurrent Abdominal Pain: A Primer for Gastroenterologists

Recurrent abdominal pain is a common reason for repeated visits to outpatient clinics and emergency departments, reflecting a substantial unmet need for timely and accurate diagnosis. A lack of awareness of some of the rarer causes of recurrent abdominal pain may impede diagnosis and delay effective management. This article identifies some of the key rare but diagnosable causes that are frequently missed by gastroenterologists and provides expert recommendations to support recognition, diagnosis, and management with the ultimate aim of improving patient outcomes.

CABOSEQ: The Effectiveness of Cabozantinib in Patients With Treatment Refractory Advanced Renal Cell Carcinoma: Results From the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC)

BACKGROUND

There are limited data evaluating the activity of cabozantinib (CABO) as second line (2L) therapy post standard of care ipilimumab-nivolumab (IPI-NIVO) or immuno-oncology(IO)/vascular endothelial growth factor inhibitor (VEGFi) combinations (IOVE).

MATERIALS AND METHODS

Using the IMDC database, we sought to identify the objective response rate, time to treatment failure (TTF) and overall survival (OS) of 2L CABO after IPI-NIVO, IOVE combinations, pazopanib or sunitinib (PAZ/SUN) or other first line (1L) therapies. Multivariable Cox regression, adjusted for underlying differences in IMDC groups, was used to compare differences in OS for 2L CABO based on preceding therapy.

RESULTS

Three hundred and forty-six patients received 2L CABO (78 post IPI NIVO, 46 post IOVE, 161 post PAZ/SUN, 61 post Other). Of the entire cohort, 12.6%, 62.6%, and 24.8% were IMDC favourable, intermediate, and poor risk, respectively. Patients that received 1L IPI-NIVO had a median OS of 21.4 (95% CI, 12.1 - NE [Not evaluable]) months compared to 15.7 (95% CI, 9.3 - NE) months in 1L IOVE and 20.7 (95% CI, 15.6 - 35.6) months in 1L PAZ/SUN, P = .28. Median TTF from the initiation of 2L CABO in the overall population was 7.6 (95% CI, 6.6 - 9.0) months. We were unable to detect a significant difference in 2L CABO OS based on type of 1L therapy received: 1L IPI-NIVO (reference group) vs. 1L IOVE HR 1.73 (95% CI, 0.83 - 3.62 P = .14), 1L PAZ/SUN 1.16 (95% CI, 0.67 - 2.00 P = .60), however given the retrospective observational nature of this work a lack of sufficient power may contribute to this.

CONCLUSION

In a large real world dataset, we identified clinically meaningful activity of 2L CABO after all evaluated contemporary 1L therapies, irrespective of whether the 1L regimen included a VEGFi. These are real world benchmarks with which to counsel our patients.

Evidence-based treatment recommendations for OTC management of chronic constipation

ABSTRACT

Chronic constipation is a common gastrointestinal condition, and most individuals self-treat with multiple over-the-counter (OTC) laxatives prior to consulting a health care provider. This brief report is a synopsis of an updated systematic review the authors conducted of published data on the efficacy and safety of OTC treatments to provide evidence-based recommendations. After applying the selection criteria, 41 randomized controlled clinical trials of ≥ 4-week duration were identified and analyzed. Standardized definitions of constipation were applied across these studies; however, definitions for stool frequency and consistency varied. Overall, the short- and long-term efficacy of polyethylene glycol-based preparations and senna were supported by good (grade A) evidence suggesting their use as first-line laxatives. Modest evidence (grade B) supported the use of other agents including the stimulants bisacodyl and sodium picosulfate, fiber, fruit-based laxatives, and magnesium oxide. Additional evidence from rigorously designed studies is needed to support the use of other options for chronic constipation. The OTC products studied were generally well tolerated with common adverse effects being abdominal pain, cramping, bloating, diarrhea, and nausea.

Re-evaluation of the Cardiovascular Safety Profile of Tegaserod: A Review of the Clinical Data

BACKGROUND AND AIMS

Tegaserod is a 5-HT₄ receptor agonist approved for irritable bowel syndrome with constipation in women <65 years of age without a history of cardiovascular ischemic events. Safety data are presented from 2 external adjudications from the 2018 Gastrointestinal Drugs Advisory Committee meeting supporting tegaserod's reintroduction after its voluntary 2007 withdrawal. Withdrawal was based on an internal adjudication using pooled placebo-controlled tegaserod data to identify potential cardiovascular ischemic signals.

METHODS

An independent committee conducted an external adjudication to evaluate 24 possible cardiovascular ischemic events (tegaserod: n = 20; placebo: n = 4) identified internally. A second independent external adjudication further evaluated these events.

RESULTS

A total of 18,645 patients were included (tegaserod: n = 11,614; placebo: n = 7031). The first adjudication identified 14 (0.075%) events (tegaserod: n = 13 [0.11%]; placebo: n = 1 [0.014%]). All patients had ≥1 cardiovascular risk factor, and 11 had ≥2. The second adjudication identified 390 events, 24 (0.13%) were classified as probable new or worsening events (tegaserod: 18 [0.16%]; placebo: 6 [0.09%]). For tegaserod, 7 (0.06%) were coronary or cerebrovascular ischemic events compared with 1 (0.01%) for placebo (odds ratio, 4.24; 95% confidence interval, 0.52-34.74; P = .273). All tegaserod patients reporting cardiovascular events had ≥1 risk, including cardiovascular disease, hyperlipidemia, ≥55 years of age, hypertension, diabetes, obesity, and smoking. Women <65 years of age without a history of cardiovascular ischemic events and ≤1 cardiovascular risk factor receiving tegaserod experienced no major adverse cardiovascular event(s).

CONCLUSIONS

Two independent, external adjudications suggest that tegaserod is safe for women <65 years of age with irritable bowel syndrome with constipation, no history of cardiovascular ischemic events, and ≤1 cardiovascular risk factor.

Baseline Predictors of Discontinuation of Prescription Drug Therapy for IBS-C: Cohort Analysis at an Integrated Healthcare System

BACKGROUND

Effective prescription drug treatment of constipation-predominant irritable bowel syndrome (IBS-C) requires patients to remain on daily therapy, yet predictive factors to optimize treatment selection are unknown.

AIMS

We assessed whether common comorbidities including chronic overlapping pain conditions (COPCs), mood disorders, or concurrent medications influence the risk of discontinuing IBS-C prescription drug therapy.

METHODS

We included all IBS-C patients who initiated treatment with the secretagogues linaclotide or lubiprostone across the Michigan Medicine healthcare system between 2012 and 2016. A Cox proportional hazards model was constructed to model time-to-treatment discontinuation as a valid, quantifiable measure of IBS medication persistence using hazards ratios (HR) with 95% confidence intervals (CI).

RESULTS

Our cohort included 225 patients on linaclotide and 492 on lubiprostone (mean age 48.3 years, 86.9% women, 46.6% with at least one COPC, 60.3% with at least one mood disorder) with an average follow-up of 2.1 years. Patients with at least one COPC (HR = 0.566; 95%CI = 0.371-0.863) and also women (HR = 0.535; 95%CI = 0.307-0.934) had a lower risk of discontinuing linaclotide, while COPCs predicted a trend toward increased discontinuation of lubiprostone (HR = 1.254; 95%CI = 0.997-1.576). Age, comorbid mood disorders, and baseline use of narcotics or benzodiazepines did not significantly mediate the risk of treatment discontinuation; our findings remained stable in univariate and multivariable analyses.

CONCLUSIONS

COPCs and sex appear to influence the likelihood of discontinuation of two commonly prescribed secretagogues, while mood disorders, narcotics, and benzodiazepines may not. Routine assessment for comorbid COPCs prior to initiating therapy may optimize IBS-C treatment selection and outcomes in practice.

Review article: current and future treatment approaches for IBS with constipation

BACKGROUND

Multiple efficacious therapies are currently available for treating irritable bowel syndrome with constipation (IBS-C). IBS-C specific survey tools that assess symptom relief, treatment satisfaction, and quality of life are important for gauging real-world effectiveness.

AIMS/METHODS

This article reviews clinical trial efficacy data as well as survey data on adequate relief and quality of life from pivotal trials for lubiprostone, linaclotide, plecanatide, tenapanor, and tegaserod. A brief discussion of agents in development with novel mechanisms of action is also provided.

RESULTS/CONCLUSIONS

Quality of life and symptom metrics should be standardized and continue to be represented in future IBS-C trials. The choice of agent should be tailored to probability of improving symptoms, safety, tolerability, and cost.

The influence of brain metastases on the central nervous system effects of methylnaltrexone: a post hoc analysis of 3 randomized, double-blind studies

PURPOSE

Peripherally acting μ-opioid receptor antagonists such as methylnaltrexone (MNTX, Relistor®) are indicated for the treatment of opioid-induced constipation (OIC). The structural properties unique to MNTX restrict it from traversing the blood-brain barrier (BBB); however, the BBB may become more permeable in patients with brain metastases. We investigated whether the presence of brain metastases in cancer patients compromises the central effects of opioids among patients receiving MNTX for OIC.

METHODS

This post hoc analysis of pooled data from 3 randomized, placebo-controlled trials included cancer patients with OIC who received MNTX or placebo. Endpoints included changes from baseline in pain scores, rescue-free laxation (RFL) within 4 or 24 h of the first dose, and treatment-emergent adverse events (TEAEs), including those potentially related to opioid withdrawal symptoms.

RESULTS

Among 356 cancer patients in the pooled population, 47 (MNTX n = 27; placebo n = 20) had brain metastases and 309 (MNTX n = 172; placebo n = 137) did not have brain metastases. No significant differences in current pain, worst pain, or change in pain scores from baseline were observed between patients treated with MNTX or placebo. Among patients with brain metastases, a significantly greater proportion of patients who received MNTX versus placebo achieved an RFL within 4 h after the first dose (70.4% vs 15.0%, respectively, p = 0.0002). TEAEs were similar between treatment groups and were generally gastrointestinal in nature and not related to opioid withdrawal.

CONCLUSION

Focal disruptions of the BBB caused by brain metastases did not appear to alter central nervous system penetrance of MNTX.

Focus on Pharmacotherapy for Irritable Bowel Syndrome with Constipation

Irritable bowel syndrome with constipation is a common disorder that significantly impairs quality of life. There are now multiple classes of therapeutics that have been shown via rigorous clinical testing to improve the abdominal and bowel symptoms attributed to irritable bowel syndrome with constipation. These include the secretagogues (lubiprostone, linaclotide, plecanatide, tenapenor) and the prokinetic agent tegaserod. This article highlights the pivotal evidence for these agents and most recent treatment guidance from the major North American gastroenterological societies. When pharmaceuticals are used, a patient-specific approach based on efficacy, safety, tolerability, access, and affordability is recommended.

Antispasmodics for Chronic Abdominal Pain: Analysis of North American Treatment Options

Chronic abdominal pain is a common gastrointestinal (GI) symptom that characterizes many functional GI disorders/disorders of gut-brain interaction, including irritable bowel syndrome, functional dyspepsia, and centrally mediated abdominal pain syndrome. The symptoms of abdominal pain in these highly prevalent disorders are often treated with antispasmodic agents. Antispasmodic treatment includes a broad range of therapeutic classes with different mechanisms of action, including anticholinergic/antimuscarinic agents (inhibition of GI smooth muscle contraction), calcium channel inhibitors (inhibition of calcium transport into GI smooth muscle), and direct smooth muscle relaxants (inhibition of sodium and calcium transport). The aim of this review article was to examine the efficacy and safety of antispasmodics available in North America (e.g., alverine, dicyclomine, hyoscine, hyoscyamine, mebeverine, otilonium, pinaverium, and trimebutine) for the treatment of chronic abdominal pain in patients with common disorders of gut-brain interaction. For the agents examined, comparisons of studies are limited by inconsistencies in treatment dosing and duration, patient profiles, and diagnostic criteria employed. Furthermore, variability in study end points limits comparisons. Risk of selection, performance, detection, attrition, and reporting bias also differed among studies, and in many cases, risks were considered "unclear." The antispasmodics evaluated in this review, which differ in geographic availability, were found to vary dramatically in efficacy and safety. Given these caveats, each agent should be considered on an individual basis, rather than prescribed based on information across the broad class of agents.

Tegaserod for Irritable Bowel Syndrome With Constipation in Women Younger Than 65 Years Without Cardiovascular Disease: Pooled Analyses of 4 Controlled Trials

INTRODUCTION

Tegaserod was the first US Food and Drug Administration-approved drug for irritable bowel syndrome with constipation (IBS-C) in women and was recently reapproved for use. Recognizing that clinical trials were performed almost 20 years ago, we performed an integrated analysis on patient-reported outcomes relevant to current practice including previously unpublished data.

METHODS

Data from 4 12-week, randomized, placebo-controlled trials evaluating tegaserod 6 mg b.i.d. in patients with IBS-C were pooled. We analyzed 2 groups: all women (overall population) and women younger than 65 years without a history of cardiovascular ischemic events (indicated population). The primary end point was subjective global assessment of IBS-C symptom relief. Responders rated themselves as "considerably" or "completely" relieved ≥50% of the time or at least "somewhat relieved" 100% of the time over the last 4 weeks.

RESULTS

The overall and indicated populations included 2,939 (tegaserod [n = 1,478]; placebo [n = 1,461]) and 2,752 (tegaserod [n = 1,386]; placebo [n = 1,366]) participants, respectively. The pooled odds ratios (95% confidence interval) for clinical response during the last 4 weeks in the overall and indicated populations with tegaserod were 1.37 (1.18, 1.59; P < 0.001) and 1.38 (1.18, 1.61; P < 0.001). In the overall and indicated populations, clinical response rates for tegaserod during the last 4 weeks were 43.3% and 44.1% versus 35.9% and 36.5% with placebo (P < 0.001). Adverse events were similar between groups. No significant cardiovascular events related to tegaserod were observed in patients with ≤1 cardiac risk factor.

DISCUSSION

Tegaserod 6 mg b.i.d. reduced IBS-C symptoms in overall and US Food and Drug Administration-indicated populations (women aged <65 years with no history of cardiovascular ischemic events).

Efficacy and Safety of Neostigmine and Decompressive Colonoscopy for Acute Colonic Pseudo-Obstruction: A Single-Center Analysis

Background

Acute colonic pseudo-obstruction (ACPO) is characterized by acute colonic dilation in the absence of anatomical obstruction. Neostigmine is an acetylcholinesterase inhibitor recommended as first-line salvage therapy for uncomplicated ACPO. Decompressive colonoscopy is recommended if neostigmine is contraindicated or unsuccessful. There is a need to better characterize relative efficacy and factors impacting treatment choice. The aim of the study was to examine the use, efficacy, and safety of neostigmine and decompressive colonoscopy in the management of ACPO at a single academic center.

Methods

Patients ≥ 18 years of age meeting established criteria for uncomplicated ACPO and with cecal diameter ≥ 10 cm on imaging between 1999 and 2019 were identified. Individuals were categorized as having received supportive care alone or subsequent trials of neostigmine or decompressive colonoscopy. Demographics and pre- and post-intervention data were collected, including indication and contraindication to intervention used, time to intervention, initial response, and adverse events.

Results

In 46 cases of ACPO (N = 42 patients), all but one individual received initial supportive care. Seven responded to conservative measures alone. Of the patients failing supportive care, 15 cases were initially treated with neostigmine (response rate 86.7%) and 24 initially underwent decompressive colonoscopy (response rate 95.8%) (P = 0.390). One episode of transient bradycardia, resolved with atropine, occurred in the neostigmine group. One patient experienced respiratory instability during colonoscopy.

Conclusions

Both neostigmine and decompressive colonoscopy appear effective for treating uncomplicated ACPO in individuals failing conservative therapy. Adverse events were infrequent in both cohorts. Future prospective studies examining treatment for ACPO should focus on whether either intervention is superior to the other.

Improved work productivity and health-related quality of life in patients with irritable bowel syndrome with diarrhea receiving eluxadoline following inadequate response to loperamide

BACKGROUND: Irritable bowel syndrome with diarrhea (IBS-D) is a chronic disorder of gut-brain interaction that negatively affects work productivity and health-related quality of life (HRQOL). IBS-D therapeutic options are limited and include loperamide, an over-the-counter μ-opioid receptor agonist commonly used as an antidiarrheal agent, and eluxadoline, a mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist approved in the United States for the treatment of IBS-D in adults. OBJECTIVE: To characterize the effect of eluxadoline on work productivity and HRQOL in patients with IBS-D with previous inadequate response to loperamide. METHODS: The Work Productivity and Activity Impairment Questionnaire for IBS-D (WPAI:IBS-D), Centers for Disease Control and Prevention Healthy Days Core Module (CDC HRQOL-4), and EuroQoL-5 Dimension (EQ-5D) instruments were administered at baseline and week 12 of a phase 4 clinical trial (RELIEF), assessing the efficacy and safety of eluxadoline treatment in adults with IBS-D reporting previous inadequate response to loperamide. Changes from baseline to week 12 for each assessment were evaluated using an analysis of covariance model. Indirect costs were calculated by converting overall work productivity losses into monetary values. RESULTS: A total of 346 patients were randomized to either eluxadoline (n = 172) or placebo (n = 174). From baseline to week 12, compared with placebo, twice-daily treatment with eluxadoline resulted in significantly greater reductions in absenteeism (2.6%; P = 0.046). Numerically greater decreases in presenteeism, overall work productivity loss, and daily activity impairment were also observed in patients receiving eluxadoline compared with those receiving placebo (P = not significant for each). Numerical reductions in overall work productivity loss from baseline to week 12 translate to approximately 2.4 hours per patient per week (123 hours annually) and correspond to an avoided overall work loss of $4,503 annually for an employee with IBS-D treated with eluxadoline. In addition, from baseline to week 12, treatment with eluxadoline led to a significantly greater reduction in the number of unhealthy days experienced (-1.7 days; P = 0.042), as well as numerical improvements in EQ-5D measures in comparison with placebo (P = not significant for each). CONCLUSIONS: In patients with IBS-D reporting inadequate response to loperamide, eluxadoline treatment was associated with significant reductions in absenteeism and the number of unhealthy days experienced. Eluxadoline treatment of IBS-D may lead to significant cost savings via mitigation of losses in work productivity. DISCLOSURES: This study was sponsored by Allergan plc (before acquisition by AbbVie, Inc.). Allergan plc and/or AbbVie, Inc., was involved in the study design, collection, analysis, interpretation of the data, writing of the report, and the decision to submit the report for publication. Abel and Burslem are employees of AbbVie, Inc., and own stock/stock options. Brenner has served as a consultant, speaker, and/or advisor for Allergan plc (before acquisition by AbbVie, Inc.), Alnylam, Alpha Sigma, Arena, Bayer, Ironwood Pharmaceuticals, Salix Pharmaceuticals, Shire, Synergy, and Takeda Pharmaceuticals. He is also supported in research by an unrestricted gift from the Irene D. Pritzker Foundation. Sayuk has served as a consultant and speaker for Allergan plc (before acquisition by AbbVie, Inc.), Gi Health Foundation, Ironwood Pharmaceuticals, Salix Pharmaceuticals, and Synergy. Portions of the current work were presented at AMCP Nexus; October 22-25, 2018; Orlando, FL.

A237 IMPROVEMENT IN ABDOMINAL SYMPTOMS WITH LINACLOTIDE IN PATIENTS WITH IRRITABLE BOWEL SYNDROME WITH CONSTIPATION: RESULTS FROM A PHASE 3B TRIAL

Background

Linaclotide (LIN) is a guanylate cyclase-C agonist approved to treat irritable bowel syndrome with constipation (IBS-C) in adults. Abdominal symptoms are important to patients with IBS-C. In a recent Phase 3b study, LIN significantly improved a composite score of abdominal bloating, pain, and discomfort (Abdominal Score), which was used as the primary endpoint in the study.

Aims

To evaluate the efficacy of LIN for improving additional efficacy abdominal symptom endpoints in a randomized, double-blind, placebo (PBO)-controlled Phase 3 study of LIN in patients with IBS-C.

Methods

Adults with IBS-C were randomized to PBO (N=308) or LIN 290 μg (N=306) once daily for 12 weeks. Patients recorded their daily abdominal symptoms, including the individual items of bloating, pain, and discomfort, using an 11-point scale (0–10; 0=none, 10=worst possible). The primary endpoint was the Abdominal Score. Additional efficacy endpoints included 6/12-week abdominal pain and constipation (APC)+1 responder, 6/12-week abdominal bloating responder, 6/12-week abdominal pain responder, and 6/12-week abdominal discomfort responder. For individual symptoms, a responder was a patient who had an improvement from baseline of ≥2 points in the respective endpoint for ≥6 of the 12 weeks. Changes from baseline (CFB) over 12 weeks in abdominal bloating, pain, and discomfort were evaluated using a mixed model with repeated measures framework. Proportions of responders were compared between groups for each responder endpoint using a Cochran-Mantel-Haenszel test.

Results

614 patients (mean age, 46.7 years; 81% female; similar baseline abdominal symptoms) were randomized. LIN-treated patients had greater least-squares mean (LSM) CFB in abdominal bloating (LSM difference [95% CI]: –0.889 [–1.249, –0.530], p&lt;0.001), pain (–0.881 [–1.238, –0.524], p&lt;0.001), and discomfort (–0.837 [–1.196, –0.478], p&lt;0.001) compared to PBO-treated patients. There was a greater proportion of LIN-treated vs. PBO-treated patients who were 6/12-week APC+1 (29% vs. 17%; p=0.0003), bloating (40% vs. 24%; p&lt;0.001), pain (42% vs. 25%; p&lt;0.001), and discomfort (42% vs. 26%; p&lt;0.001) responders (Figure). Diarrhea was the most common treatment-emergent adverse event (LIN: 4.6%; PBO: 1.6%).

Conclusions

LIN significantly improved multiple abdominal symptom and secondary responder endpoints in patients with IBS-C. These results support the effectiveness of LIN for improving a spectrum of abdominal symptoms in IBS-C.

Funding Agencies

This study was sponsored by Allergan plc, Dublin, Ireland (prior to acquisition by AbbVie Inc.). Writing and editorial assistance were provided to the authors by Brittany Y. Jarrett, PhD, Jane Beck, MA, and Rebecca Fletcher, BA(Hons) of Complete HealthVizion, Inc., Chicago, IL, USA and funded by Allergan plc (prior to acquisition by AbbVie Inc.).

Naldemedine for the treatment of opioid-induced constipation in adults with chronic noncancer pain

This review aims to summarize the efficacy data for naldemedine, a member of the novel peripherally acting μ-opioid receptor antagonists (PAMORAs), which gained US FDA approval for the treatment of opioid-induced constipation in adults with chronic noncancer pain-related syndromes in 2017. In Phase III trials, patients receiving naldemedine were significantly more likely to meet the primary end point ≥3 spontaneous bowel movements/week and an increase of ≥1 spontaneous bowel movement/week from baseline for at least 9/12 weeks compared to placebo (p < 0.0001). The most frequent adverse events were abdominal pain (8%) and diarrhea (7%). Based on available data, naldemedine appears to be an effective and safe first-line therapy for the treatment of opioid-induced constipation in adults with chronic noncancer pain.

Efficacy and safety of linaclotide for opioid-induced constipation in patients with chronic noncancer pain syndromes from a phase 2 randomized study

Constipation is the most common adverse event (AE) of opioid therapy. This multicenter, phase 2 study evaluated the efficacy and safety of linaclotide in treating opioid-induced constipation (OIC) in patients with chronic noncancer pain syndromes (NCT02270983). Adults with OIC (<3 spontaneous bowel movements [SBMs]/week) related to chronic noncancer pain were randomized 1:1:1 to receive linaclotide 145 µg, linaclotide 290 µg, or placebo once daily for 8 weeks. The primary endpoint was change from baseline in 8-week SBM frequency rate (SBMs/week). Secondary efficacy endpoints included 6/8-week SBM 3 + 1 responders, time to first SBM, and changes from baseline in 8-week stool consistency, abdominal bloating, and straining. Additional endpoints included treatment satisfaction and adequate relief responders. In total, 254 patients were randomized: 87, 88, and 79 received linaclotide 145 µg, linaclotide 290 µg, and placebo, respectively. The mean changes from baseline in SBMs/week during the treatment period were 2.9 and 3.5 in the linaclotide 145 and 290 µg groups (P < 0.01 for both doses), respectively, vs 1.6 in the placebo group. Diarrhea, the most common AE, was generally mild, resulting in 1.1%, 5.7%, and 1.3% of patients discontinuing in the linaclotide 145 μg, linaclotide 290 μg, and placebo groups, respectively. No serious AEs related to diarrhea were reported in any treatment group. Compared with placebo, linaclotide-treated patients had significant improvements in stool consistency, straining, abdominal bloating, and treatment satisfaction scores (P < 0.05). Linaclotide significantly improved OIC symptoms and was well tolerated in patients with chronic noncancer pain.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and network meta-analysis

OBJECTIVE

Opioids are increasingly prescribed in the West and have deleterious GI consequences. Pharmacological therapies to treat opioid-induced constipation (OIC) are available, but their relative efficacy is unclear. We performed a systematic review and network meta-analysis to address this deficit in current knowledge.

DESIGN

We searched MEDLINE, EMBASE, EMBASE Classic and the Cochrane central register of controlled trials through to December 2017 to identify randomised controlled trials (RCTs) of pharmacological therapies in the treatment of adults with OIC. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Efficacy and safety of pharmacological therapies was reported as a pooled relative risk (RR) with 95% CIs to summarise the effect of each comparison tested and ranked treatments according to their P-score.

RESULTS

Twenty-seven eligible RCTs of pharmacological therapies, containing 9149 patients, were identified. In our primary analysis, using failure to achieve an average of ≥3 bowel movements (BMs) per week with an increase of ≥1 BM per week over baseline or an average of ≥3 BMs per week, to define non-response, the network meta-analysis ranked naloxone first in terms of efficacy (RR=0.65; 95% CI 0.52 to 0.80, P-score=0.84), and it was also the safest drug. When non-response to therapy was defined using failure to achieve an average of ≥3 BMs per week, with an increase of ≥1 BM per week over baseline, naldemedinewas ranked first (RR=0.66; 95% CI 0.56 to 0.77, P score=0.91) and alvimopan second (RR=0.74; 95% CI 0.57 to 0.94, P-score=0.71).

CONCLUSION

In network meta-analysis, naloxone and naldemedine appear to be the most efficacious treatments for OIC. Naloxone was the safest of these agents.

(Can't Get No) Patient Satisfaction: The Predictive Power of Demographic, GI, and Psychological Factors in IBS Patients

GOALS

The goal of this study is to assess: (1) the relative contribution of patient factors to satisfaction ratings in irritable bowel syndrome (IBS) patients and (2) the relationship between patient satisfaction (PS) and the number of diagnostic tests patients underwent prior to receiving IBS diagnosis.

BACKGROUND

Although PS is regarded as an important indicator of quality of care, little is known about its determinants.

STUDY

A total of 448 Rome III-diagnosed patients (M age=41 y; 79% F), whose GI symptoms were at least moderate in severity completed patient-reported outcome measures as part of pretreatment evaluation of an NIH-funded clinical trial. PS was measured with the 11-point Hospital Consumer Assessment of Healthcare Providers and Systems global rating scale modified to assess for IBS treatments. A series of multiple regression analyses were conducted for demographic, IBS-specific, general physical health, and psychological predictors before running a final model of significant predictors from each domain.

RESULTS

The final regression model was significant, F6,419=6.34, P<0.001, R=0.08, with race, insurance, number of diagnostic tests, and lower neuroticism predicting PS. Medical tests were rendered nonsignificant when history of seeking care from a gastroenterologist was introduced into the equation.

CONCLUSIONS

Contrary to hypotheses, neither the IBS symptom severity nor quality of life impairment predicted PS. Patient factors such as a neurotic personality style and sociodemographic profile had a significant but modest impact on PS. Pattern of regression analyses suggests that patients may turn to their gastroenterologist for testing for reassurance, which may in the long-term fuel demand for more testing.

Efficacy, safety, and tolerability of plecanatide in patients with irritable bowel syndrome with constipation: results of two phase 3 randomized clinical trials

OBJECTIVES

Two identical, phase 3, randomized, double-blind, placebo-controlled trials evaluated the efficacy and safety of plecanatide in patients with irritable bowel syndrome with constipation (IBS-C).

METHODS

Adults meeting Rome III criteria for IBS-C were randomized (1:1:1) to placebo or plecanatide (3 or 6 mg) for 12 weeks. The primary efficacy end point was the percentage of overall responders (patients reporting ≥30% reduction from baseline in worst abdominal pain plus an increase of ≥1 complete spontaneous bowel movement (CSBM)/week from baseline in the same week for ≥6 of 12 treatment weeks). Safety was assessed by adverse events (AEs).

RESULTS

Overall, 2189 individuals were randomized across the two studies and 1879 completed the studies. Demographic and baseline characteristics were similar across treatment groups and between studies. The percentage of overall responders in Study 1 was 30.2% and 29.5% for plecanatide 3 and 6 mg, respectively, vs. 17.8% placebo (P < 0.001 for each dose vs. placebo), and in Study 2 was 21.5% (P = 0.009) and 24.0% (P < 0.001) for plecanatide 3 and 6 mg, respectively, compared to 14.2% for placebo. The percentage of sustained efficacy responders (overall responders plus weekly responders for ≥2 of last 4 weeks of the 12-week treatment period) was significantly greater for both doses of plecanatide vs. placebo across both studies. All secondary end points (stool frequency/consistency, straining, abdominal symptoms) showed statistically significant improvements compared with placebo. The most common AE was diarrhea (3 mg, 4.3%; 6 mg, 4.0%; placebo, 1.0%). Discontinuation due to diarrhea was infrequent (3 mg, 1.2%; 6 mg, 1.4%; placebo, 0).

CONCLUSIONS

Plecanatide significantly improved both abdominal pain and constipation symptoms of IBS-C with minimal associated side effects and high levels of tolerability.

Radar plots: A novel modality for displaying disparate data on the efficacy of eluxadoline for the treatment of irritable bowel syndrome with diarrhea

BACKGROUND

Patients with irritable bowel syndrome with diarrhea (IBS-D) experience a range of abdominal and bowel symptoms; successful management requires alleviation of this constellation of symptoms. Eluxadoline, a locally active mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist, is approved for the treatment of IBS-D in adults based on the results of 2 Phase 3 studies. Radar plots can facilitate comprehensive, visual evaluation of diverse but interrelated efficacy endpoints.

METHODS

Two double-blind, placebo-controlled, Phase 3 trials (IBS-3001 and IBS-3002) randomized patients meeting Rome III criteria for IBS-D to twice-daily eluxadoline 75 or 100 mg or placebo. Radar plots were prepared showing pooled Weeks 1-26 response rates for the primary efficacy composite endpoint (simultaneous improvement in abdominal pain and stool consistency), stool consistency, abdominal pain, urgency-free days, and adequate relief, and change from baseline to Week 26 in IBS-D global symptom score, abdominal discomfort, abdominal pain, abdominal bloating, and daily number of bowel movements.

KEY RESULTS

The studies enrolled 2428 patients. Eluxadoline increased Weeks 1-26 responder proportions vs placebo for the composite endpoint, stool consistency, abdominal pain, urgency-free days, and adequate relief. Changes from baseline to Week 26 in IBS-D global symptom score, abdominal discomfort, abdominal pain, abdominal bloating, and number of bowel movements were greater with eluxadoline vs placebo.

CONCLUSIONS AND INFERENCES

Data presentation in radar plot format facilitates interpretation across multiple domains, demonstrating that eluxadoline treatment led to improvements vs placebo across 13 endpoints representing the range of symptoms experienced by patients with IBS-D.

Gut Microbiota-Based Therapies for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, heterogeneous disorder characterized by abdominal pain associated with changes in bowel habits. The pathogenesis of IBS is multifactorial and may relate to alterations in the gut microbiota, changes in visceral sensation and motility, and genetic and environmental factors. Administration of systemic antibiotics may increase the risk of IBS by altering gastrointestinal homeostasis. Therapeutic interventions for IBS with diarrhea that are thought to target alterations in the gut microbiota include the nonsystemic antibiotic rifaximin, the medical food serum-derived bovine immunoglobulin, prebiotics, probiotics, and dietary modification. SYN-010 is a modified-release statin formulation that reduces methane production by Methanobrevibacter smithii and is currently in development for the treatment of patients with constipation-predominant IBS. Use of these interventions in the management of patients with IBS may function to restore a healthy gut microbiota and ameliorate symptoms of IBS.

Abnormal esophageal acid exposure on high-dose proton pump inhibitor therapy is common in systemic sclerosis patients

BACKGROUND

Esophageal dysfunction and gastro-esophageal reflux disease (GERD) are common among patients with systemic sclerosis (SSc). Although high-dose proton pump inhibitors (PPIs) typically normalize esophageal acid exposure, the effectiveness of PPI therapy has not been systematically studied in SSc patients. The aim of this study was to characterize reflux in SSc patients on high-dose PPI using esophageal pH-impedance testing.

METHODS

In this case-controlled retrospective analysis, 38 patients fulfilling 2013 American College of Rheumatology SSc criteria who underwent esophageal pH-impedance testing on twice-daily PPI between January 2014 and March 2017 at a tertiary referral center were compared with a control-cohort of 38 non-SSc patients matched for PPI formulation and dose, hiatal hernia size, age, and gender. Patient clinical characteristics, including endoscopy and high-resolution manometry findings, were assessed via chart review.

KEY RESULTS

On pH-impedance, SSc patients had higher acid exposure times (AETs) than controls. Sixty-one percent of the SSc patients and 18% of the control patients had a total AET ≥4.5% (P < .001). Systemic sclerosis patients also had significantly longer AETs, longer median bolus clearance, and lower nocturnal impedance values.

CONCLUSIONS & INFERENCES

Abnormal esophageal acid exposure despite high-dose PPI therapy was common among patients with SSc. The lack of increased reflux episodes in the SSc patients, and longer bolus clearance times and lower nocturnal impedance, supports ineffective clearance as the potential mechanism. Systemic sclerosis patients may require adjunctive therapies to PPIs to control acid reflux.

Spotlight on naldemedine in the treatment of opioid-induced constipation in adult patients with chronic noncancer pain: design, development, and place in therapy

Opioid-induced constipation (OIC) is an increasingly prevalent problem in the USA due to the growing use of opioids. A novel class of therapeutics, the peripherally acting μ-opioid receptor antagonists (PAMORAs), has been developed to mitigate the deleterious effects of opioids in the gastrointestinal tract while maintaining central analgesia and minimizing opioid withdrawal. This review aimed to summarize the literature on naldemedine, the third PAMORA to gain US Food and Drug Administration (FDA) approval for the treatment of OIC in adults with chronic noncancer pain-related syndromes. Naldemedine has a chemical structure similar to naltrexone, an opioid receptor antagonist, with chemical modifications that limit its ability to cross the blood-brain barrier. Naldemedine was evaluated in two Phase II and three Phase III clinical trials prior to gaining FDA approval. In two pivotal identical Phase III trials, COMPOSE-I (NCT 01965158) and COMPOSE-II (NCT 01993940), patients receiving naldemedine were significantly more likely to respond when compared with placebo (COMPOSE-I: 47.6 vs 34.6%, P=0.002 and COMPOSE-II: 52.5 vs 33.6%, P<0.0001). The most frequent adverse events were abdominal pain (8%) and diarrhea (7%) - rates similar to the other PAMORAs. Based on the available data, naldemedine appears to be an effective and safe drug for the treatment of OIC in adults with chronic noncancer pain.

Opioid-Related Constipation in Patients With Non-cancer Pain Syndromes: a Review of Evidence-Based Therapies and Justification for a Change in Nomenclature

PURPOSE OF REVIEW

Opioids are a mainstay in the treatment of chronic non-cancer pain syndromes, but their analgesic benefits come at a cost as opioid-related constipation occurs in 40-80% of individuals taking chronic opioids. Furthermore, as 10-20% of the population suffers from constipation at baseline, it should be expected that while a proportion of individuals will develop constipation as a direct consequence of opioids (OIC), others will experience it as an exacerbation of their baseline constipation (OEC). Herein, we review the evidence-based data for treatments directed at opioid-related constipation focusing on individuals with non-cancer pain syndromes and provide a template for the development of differentiated treatment algorithms for OIC and OEC.

RECENT FINDINGS

Historical and current treatment protocols recommend traditional laxatives, but these are ineffective in up to 50%, due in part to the heterogeneous pathogenesis of constipation. Therapeutic decisions must be tailored to account for this overlapping pathogenesis. OIC and OEC are distinct entities. As such, additional research and guidelines should address these as different patient populations.

Chronic Constipation

Chronic constipation is a common disorder that affects approximately 20% of the population and significantly impacts an individual's quality of life. The diagnosis can be made using standard criteria, and in the absence of alarm signs or symptoms, a determination of the underlying etiology/etiologies should be undertaken. In many instances, these will be gleaned from the history and physical examination. Specialized diagnostic testing may be warranted after the failure of initial laxative trials. Many therapeutic classes of laxatives exist with recent analyses indicating that practicing physicians prefer to use over-the-counter therapies in lieu of more strongly evidence-based prescription pharmaceuticals.

Analysis of opioid-mediated analgesia in Phase III studies of methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain

Background

Subcutaneous methylnaltrexone is efficacious and well tolerated for opioid-induced constipation (OIC) but may theoretically disrupt opioid-mediated analgesia.

Methods

Opioid use, pain intensity, and opioid withdrawal (Objective Opioid Withdrawal Scale [OOWS] and Subjective Opiate Withdrawal Scale [SOWS] scores) were reported in a randomized, double-blind trial with an open-label extension (RCT) and an open-label trial (OLT) evaluating safety in adults with chronic noncancer pain. In the RCT, patients taking ≥50 mg of oral morphine equivalents daily with <3 rescue-free bowel movements weekly received methyl naltrexone 12 mg once daily (n=150), every other day (n=148), or placebo (n=162) for 4 weeks, followed by open-label methylnaltrexone 12 mg (as needed [prn]; n=364) for 8 weeks. In the OLT, patients (n=1,034) on stable opioid doses with OIC received methylnaltrexone 12 mg prn for up to 48 weeks.

Results

Minimal fluctuations of median morphine equivalent dose from baseline (BL) were observed in the RCT double-blind period (BL, 154.8–161.0 mg/d; range, 137.1–168.0 mg/d), RCT open-label period (BL, 156.3–174.6; range, 144.0–180.0) and OLT (BL, 120 mg/d; range, 117.3–121.1 mg/d). No significant change from BL in pain intensity score occurred in any group at weeks 2 or 4 (both P≥0.1) of the RCT double-blind period, and scores remained stable during the open-label period and in the OLT (mean change, −0.2 to 0.1). Changes from BL in OOWS and SOWS scores during the double-blind period were not significantly impacted by methylnaltrexone exposure at weeks 2 or 4 (P>0.05 for all).

Conclusion

Methylnaltrexone did not affect opioid-mediated analgesia in patients with chronic noncancer pain and OIC.

Gender differences in irritable bowel syndrome: the interpersonal connection

BACKGROUND

While irritable bowel syndrome (IBS) affects women more than men, the reasons are unclear. Research on the female preponderance of IBS has focused on gender differences in sex-linked biological processes; much less attention has been paid to the role of psychosocial factors. Interpersonal difficulties may be one source of stress that may significantly impact on women with IBS. Because of the importance that women attach to relationships, we suspected they would be more reactive to interpersonal stress.

METHODS

A total of 283 (M age = 41 years, F = 80%), Rome III-diagnosed IBS patients completed a test battery that included the IBS Symptom Severity Scale, McGill Pain Questionnaire, Inventory of Interpersonal Problems (IIP), interpersonal support evaluation list (social support), Negative Interactions Scale, Brief Symptom Inventory (distress), Beck Depression Inventory, Anxiety Sensitivity Inventory, and IBS-Quality of Life as part of baseline assessment of an NIH trial.

KEY RESULTS

Males scored higher on two IIP scales reflecting a hostile-dominant interpersonal pattern, and reported less social support. The quality of relationship problems (more interpersonal difficulties, lower support) correlated with IBS symptom severity as measured mainly by gastroenterologists.

CONCLUSIONS & INFERENCES

Male, not female, IBS patients reported more interpersonal difficulties. Male patients-a population for whom little is known-are characterized by hostile-dominant interpersonal problems. This finding has clinical importance, given that relationship problems may influence MDs' estimation of IBS symptom severity and undermine the physician-patient relationship.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and meta-analysis

OBJECTIVES

There has been no definitive synthesis of the evidence for any benefit of available pharmacological therapies in opioid-induced constipation (OIC). We conducted a systematic review and meta-analysis to address this deficit.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials through to December 2012 to identify placebo-controlled trials of μ-opioid receptor antagonists, prucalopride, lubiprostone, and linaclotide in the treatment of adults with OIC. No minimum duration of therapy was required. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Effect of pharmacological therapies was reported as relative risk (RR) of failure to respond to therapy, with 95% confidence intervals (CIs).

RESULTS

Fourteen eligible randomized controlled trials (RCTs) of μ-opioid receptor antagonists, containing 4,101 patients, were identified. These were superior to placebo for the treatment of OIC (RR of failure to respond to therapy=0.69; 95% CI 0.63-0.75). Methylnaltrexone (six RCTs, 1,610 patients, RR=0.66; 95% CI 0.54-0.84), naloxone (four trials, 798 patients, RR=0.64; 95% CI 0.56-0.72), and alvimopan (four RCTs, 1,693 patients, RR=0.71; 95% CI 0.65-0.78) were all superior to placebo. Total numbers of adverse events, diarrhea, and abdominal pain were significantly commoner when data from all RCTs were pooled. Reversal of analgesia did not occur more frequently with active therapy. Only one trial of prucalopride was identified, with a nonsignificant trend toward higher responder rates with active therapy. Two RCTs of lubiprostone were found, with significantly higher responder rates with lubiprostone in both, but reporting of data precluded meta-analysis.

CONCLUSIONS

μ-Opioid receptor antagonists are safe and effective for the treatment of OIC. More data are required before the role of prucalopride or lubiprostone in the treatment of OIC are clear.

Type, rather than number, of mental and physical comorbidities increases the severity of symptoms in patients with irritable bowel syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) has significant mental and physical comorbidities. However, little is known about the day-to-day burden these comorbidities place on quality of life (QOL), physical and mental function, distress, and symptoms of patients.

METHODS

We collected cross-sectional data from 175 patients with IBS, which was diagnosed on the basis of Rome III criteria (median age, 41 years; 78% women), who were referred to 2 specialty care clinics. Patients completed psychiatric interviews, a physical comorbidity checklist, the IBS Symptom Severity Scale, the IBS-QOL instrument, the Brief Symptom Inventory, the abdominal pain intensity scale, and the Short Form-12 Health Survey.

RESULTS

Patients with IBS reported an average of 5 comorbidities (1 mental, 4 physical). Subjects with more comorbidities reported worse QOL after adjusting for confounding variables. Multiple linear regression analyses indicated that comorbidity type was more consistently and strongly associated with illness burden indicators than disease counts. Of 10,296 possible physical-mental comorbidity pairs, 6 of the 10 most frequent dyads involved specific conditions (generalized anxiety, depression, back pain, agoraphobia, tension headache, and insomnia). These combinations were consistently associated with greater illness and symptom burdens (QOL, mental and physical function, distress, more severe symptoms of IBS, and pain).

CONCLUSIONS

Comorbidities are common among patients with IBS. They are associated with distress and reduced QOL. Specific comorbidities are associated with more severe symptoms of IBS.

Negative aspects of close relationships are more strongly associated than supportive personal relationships with illness burden of irritable bowel syndrome

OBJECTIVE

This study assessed the relative magnitude of associations between IBS outcomes and different aspects of social relationships (social support, negative interactions).

METHOD

Subjects included 235 Rome III diagnosed IBS patients (M age=41yrs, F=78%) without comorbid GI disease. Subjects completed a testing battery that included the Interpersonal Support Evaluation List (Social Support or SS), Negative Interaction (NI) Scale, IBS Symptom Severity Scale (IBS-SSS), IBS-QOL, BSI Depression, STAI Trait Anxiety, SOMS-7 (somatization), Perceived Stress Scale, and a medical comorbidity checklist.

RESULTS

After controlling for demographic variables, both SS and NI were significantly correlated with all of the clinical variables (SS r's=.20 to .36; NI r's=.17 to .53, respectively; ps<.05) save for IBS symptom severity (IBS-SSS). NI, but not SS, was positively correlated with IBS-SSS. After performing r-to-z transformations on the correlation coefficients and then comparing z-scores, the correlation between perceived stress, and NI was significantly stronger than with SS. There was no significant difference between the strength of correlations between NI and SS for depression, somatization, trait anxiety, and IBSQOL. A hierarchical linear regression identified both SS and NI as significant predictors of IBS-QOL.

CONCLUSIONS

Different aspects of social relationships - support and negative interactions - are associated with multiple aspects of IBS experience (e.g. stress, QOL impairment). Negative social relationships marked by conflict and adverse exchanges are more consistently and strongly related to IBS outcomes than social support.

Functional Dyspepsia Treatment Trial (FDTT): a double-blind, randomized, placebo-controlled trial of antidepressants in functional dyspepsia, evaluating symptoms, psychopathology, pathophysiology and pharmacogenetics

BACKGROUND

Functional dyspepsia (FD) is a common problem affecting up to 10-25% of individuals. FD accounts for significant health care costs and affects quality of life but has no definitive treatment.

OBJECTIVES

The Functional Dyspepsia Treatment Trial (FDTT) aims to test whether treatment with an antidepressant (amitriptyline or escitalopram) leads to improvement of symptoms in patients with moderate to severe FD.

DESIGN

The FDTT is an international multicenter, parallel group, randomized, double-blind, placebo-controlled trial to evaluate whether 12 weeks of treatment with escitalopram or amitriptyline improves FD symptoms compared to treatment with placebo. Secondly, it is hypothesized that acceleration of solid gastric emptying, reduction of postprandial satiation, and enhanced gastric volume change with a meal will be significant positive predictors of short- and long-term outcomes for those on antidepressants vs. placebo. The third aim is to examine whether polymorphisms of GNβ3 and serotonin reuptake transporter influence treatment outcomes in FD patients receiving a tricyclic antidepressant, selective serotonin reuptake inhibitor therapy, or placebo.

METHODS

The FDTT enrollment began in 2006 and is scheduled to randomize 400 patients by the end of 2012 to receive an antidepressant or placebo for 12 weeks, with a 6-month post-treatment follow-up. The study incorporates multiple validated questionnaires, physiological testing, and specific genetic evaluations. The protocol was approved by participating centers' Institutional Review Boards and an independent Data Safety Monitoring Board was established for monitoring to ensure patient safety and a single interim review of the data in December 2010 (ClinicalTrials.gov number NCT00248651).