Safety and efficacy of linaclotide in children aged 7-17 years with irritable bowel syndrome with constipation

OBJECTIVES

Linaclotide, a guanylate cyclase-C agonist, was recently approved in the United States for the treatment of children 6-17 years old with functional constipation. This study evaluated the safety and efficacy of various linaclotide doses in children 7-17 years old with irritable bowel syndrome with constipation (IBS-C).

METHODS

In this 4-week, randomized, double-blind, placebo-controlled, parallel-group, Phase 2 study, children with IBS-C were randomized to once-daily placebo or linaclotide (Dose A: 18 or 36 µg, B: 36 or 72 µg, and C: 72 µg or 145 µg, or 290 µg); those aged 7-11 years in a 1:1:1:1 allocation based on weight (18 to <35 kg:18 µg, 36 µg, or 72 µg; or ≥35 kg: 36 µg, 72 µg, or 145 µg), and those aged 12-17 years in a 1:1:1:1:1 allocation (the higher option of Doses A-C or 290 µg). The primary efficacy endpoint was a change from baseline in 4-week overall spontaneous bowel movement (SBM) frequency rate over the treatment period. Adverse events and clinical laboratory measures were also assessed.

RESULTS

Efficacy, safety, and tolerability were assessed in 101 patients. In the intent-to-treat population, numerical improvement was observed in overall SBM frequency rate with increasing linaclotide doses (A: 1.62, B: 1.52, and C: 2.30, 290 µg: 3.26) compared with placebo. The most reported treatment-emergent adverse events were diarrhea and pain, with most cases being mild and none being severe.

CONCLUSIONS

Linaclotide was tolerated well in this pediatric population, showing numerical improvement in SBM frequency compared with placebo.

Lessons learned: Chronic idiopathic constipation patient experiences with over-the-counter medications

INTRODUCTION

Chronic idiopathic constipation (CIC) is a prevalent functional gastrointestinal disorder diagnosed based on patient-reported symptoms and the absence of structural gastrointestinal abnormalities. Individuals with CIC typically institute dietary changes and use stool softeners or over-the-counter (OTC) laxatives, possibly at the direction of a healthcare provider, before prescription medications for CIC are initiated. Although highly prevalent, there is limited information regarding CIC patient experiences with OTC medications.

METHODS

This post-hoc analysis used patient-reported data from a questionnaire administered during patient screening for a prospective linaclotide Phase 3b clinical trial in patients with CIC (N = 1482 screened). The questionnaire asked patients to report their experiences with OTC CIC medications over the preceding 6 months.

RESULTS

Among patients with screening responses (N = 1423), most were female (85%) and white (66%), with a mean age of 48.9 years. A high proportion of patients had used one or more OTC medications (70% had ≥1 OTC; 19% had ≥3 OTCs), with the majority being bisacodyl (33%) and polyethylene glycol (30%). The most commonly cited reason for stopping an OTC medication was insufficient symptom relief (17-40%). The majority of patients taking OTC medications reported no or little satisfaction with the medication's effect on their constipation (62%) and CIC-specific abdominal symptoms (78%). Many patients had little to no confidence in bowel movement (BM) frequency after taking OTC medications and their confidence in their ability to predict BM timing was also low (49-81% not at all confident).

CONCLUSIONS

Treatment effects on individual CIC symptoms, predictability of bowel habits, and satisfaction with treatment are all important factors for healthcare providers and patients to consider when establishing an effective treatment regimen for CIC.

TRIAL REGISTRATION NUMBER

NCT01642914.