Randomized controlled trial of linaclotide in children aged 6-17 years with functional constipation

OBJECTIVES

Linaclotide, a guanylate cyclase-C agonist, was recently approved in the United States for treatment of children 6-17 years old with functional constipation (FC). This study evaluated the safety and efficacy of several linaclotide doses in children 6-17 years old with FC.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled phase 2 study, 173 children with FC (based on Rome III criteria) were randomized to once-daily linaclotide (A: 9 or 18 μg, B: 18 or 36 μg, or C: 36 or 72 μg) or placebo in a 1:1:1:1 ratio for 6- to 11-year-olds (dosage determined by weight: 18 to <35 or ≥35 kg) and linaclotide (18, 36, 72, or 145 μg) or placebo in a 1:1:1:1:1 ratio for 12- to 17-year-olds. The primary efficacy endpoint was change from baseline in weekly spontaneous bowel movement (SBM) frequency throughout the 4-week treatment period. Adverse events (AE), clinical laboratory values, and electrocardiograms were monitored.

RESULTS

Efficacy and safety were assessed in 173 patients (52.0% aged 6-11 years; 48.0% aged 12-17 years); 162 (93.6%) completed the treatment period. A numerical improvement in mean SBM frequency was observed with increasing linaclotide doses (1.90 in 6- to 11-year-olds [36 or 72 μg] and 2.86 in 12- to 17-year-olds [72 μg]). The most reported treatment-emergent AE was diarrhea, with most cases being mild; none were severe.

CONCLUSIONS

Linaclotide was well tolerated in this pediatric population, with a trend toward efficacy in the higher doses, warranting further evaluation.

Randomized Trial of 2 Delayed-Release Formulations of Linaclotide in Patients With Irritable Bowel Syndrome With Constipation

INTRODUCTION

Immediate-release (IR) formulation of linaclotide 290 μg improves abdominal pain and constipation (APC) in patients with irritable bowel syndrome (IBS) with constipation. Delayed-release (DR) formulations were developed on the premise that targeting the ileum (delayed-release formulation 1 [DR1]) or ileocecal junction and cecum (MD-7246, formerly DR2) would modulate linaclotide's secretory effects while preserving pain relief effects.

METHODS

This phase 2b study randomized patients with IBS with constipation to placebo or 1 of 7 once-daily linaclotide doses (DR1 30, 100, or 300 μg; MD-7246 30, 100, or 300 μg; or IR 290 μg) for 12 weeks. Key efficacy endpoints were change from baseline in abdominal pain and complete spontaneous bowel movement frequency, and 6/12-week combined APC+1 responder rate.

RESULTS

Overall, 532 patients were randomized; mean age was 45.1 years, and most were women (83.3%) and White (64.7%). All linaclotide DR1 and MD-7246 groups experienced greater improvements in abdominal pain from baseline and vs placebo throughout treatment. Linaclotide DR1 and IR led to numerically greater improvements from baseline in complete spontaneous bowel movement frequency and higher APC+1 responder rates compared with placebo; MD-7246 results were similar to placebo. Diarrhea was the most common adverse event with DR1 and IR; rates were similar between MD-7246 and placebo.

DISCUSSION

Altering the site of drug delivery in the intestine might uncouple linaclotide's pain relief from secretory effects. Persistent, modest abdominal pain improvement with limited impact on bowel symptom parameters, as seen across MD-7246 doses, warrants further study of MD-7246 as a novel treatment for abdominal pain, regardless of IBS subtype.

The Impact of Stool Consistency on Bowel Movement Satisfaction in Patients With IBS-C or CIC Treated With Linaclotide or Other Medications: Real-World Evidence From the CONTOR Study

GOALS

This study aimed to characterize the impact of stool consistency on patient-reported bowel movement (BM) satisfaction in patients with irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation, with a focus on linaclotide.

BACKGROUND

As new medications for constipation become available, understanding patients' perceptions of treatment effects may help clinicians manage patient expectations and inform clinical decision-making.

MATERIALS AND METHODS

Data were derived from the Chronic Constipation and IBS-C Treatment and Outcomes Real-world Research Platform (CONTOR) study from 2 patient-reported 7-day daily BM diaries to create a dataset of 2922 diaries representing 26,524 BMs for 1806 participants. Binary variables were created for: medication(s) used in the past 24 hours and categorization of BMs as loose or watery stools (LoWS), hard or lumpy stools (HoLS), or intermediate (neither LoWS nor HoLS). The relationship between stool consistency, medication use, and BM satisfaction was analyzed using logistic regression with SEs corrected for repeated observations.

RESULTS

BMs characterized as intermediate stools and LoWS were satisfactory more often (61.2% and 51.2%, respectively) than HoLS (19.4%). Participants who reported taking linaclotide rated a similar proportion of BMs as satisfactory when described as LoWS (65.6%) or intermediate (64.1%). Linaclotide use was associated with higher odds of BMs being reported as satisfactory compared with nonlinaclotide use (odds ratio: 1.23, P<0.05).

CONCLUSIONS

Overall, CONTOR participants were more likely to report BMs classified as LoWS or intermediate as satisfactory, versus HoLS. Participants taking linaclotide were more likely to be satisfied, particularly those reporting LoWS, versus those not taking linaclotide.

Determining an optimal dose of linaclotide for use in Japanese patients with irritable bowel syndrome with constipation: A phase II randomized, double-blind, placebo-controlled study

BACKGROUND

Clinical testing to determine a suitable dose of linaclotide for Japanese patients with irritable bowel syndrome with constipation (IBS-C) was needed.

METHODS

This was a randomized, double-blind, placebo-controlled, dose-finding trial. Japanese patients with IBS-C diagnosed using Rome III criteria (n = 559, men/women: 49/510) were randomly assigned to 1 of 4 linaclotide doses (0.0625, 0.125, 0.25, or 0.5 mg) or placebo for the 12-week treatment period. The primary endpoint was responder rate of global assessment of relief of IBS symptoms during 12 weeks. The secondary endpoints included responder rates of complete spontaneous bowel movement (CSBM), SBM and abdominal pain/discomfort relief and others.

KEY RESULTS

The primary endpoint was 23.2%, 36.2%, 38.7%, 34.8%, and 38.3% in placebo (n = 112), 0.0625 (n = 116), 0.125 (n = 111), 0.25 (n = 112), and 0.5 (n = 107) mg of linaclotide groups with the difference from the placebo group in each linaclotide group (13.0%, 15.5%, 11.6%, 15.1%, P > .05). Monthly responder rate of global assessment of relief of IBS symptoms at month 3 (48.6%), responder rate of CSBM during 12 weeks (45.8%), and responder rate of abdominal pain/discomfort relief during 12 weeks (32.7%) in the 0.5 mg were significantly higher than those in placebo group (29.5%, P < .01; 25.9%, P < .01; and 18.8%, P < .05 respectively). The most frequent adverse event in the linaclotide groups was diarrhea.

CONCLUSIONS & INFERENCES

This study suggests that a linaclotide dose of 0.5 mg may be appropriate in Japanese patients with IBS-C.

Health Care Resource Use and Costs Pre- and Post-Treatment Initiation With Linaclotide: Retrospective Analyses of a U.S. Insured Population

As expected, pharmacy costs increased with the introduction of this new treatment in a market dominated by over-the-counter and generic treatments. On the other hand, outpatient GI-related and irritable bowel disease health care resource use and costs substantially decreased among commercial and Medicare patients following linaclotide treatment initiation.