Patient Attitudes Regarding Treatment Satisfaction and Bowel Movement Confidence and Predictability: A Post-hoc Comparison of Study Treatment and Prior Medication Use Based on a Phase 3b Trial of Linaclotide in CIC

Abstract

Introduction: Linaclotide (LIN) is approved in the US for adult treatment of chronic idiopathic constipation (CIC). CIC patients experience multiple bowel (infrequent bowel movements, hard/lumpy stools, straining) and abdominal (discomfort & bloating) symptoms. This analysis compared CIC patient attitudes regarding the study drug and prior constipation medications (PCMs) from a Phase 3b trial. Methods: A Phase 3b randomized, double-blind, placebo-controlled trial of LIN (145 or 290 μg) was conducted among CIC patients with prominent abdominal bloating at baseline. At screening, patients identified constipation medications used in the prior 6 months (bulk laxatives [BL], lubiprostone [LUBI]) polyethylene glycol [PEG], stimulant laxatives [SL], stool softeners [SS], wheat dextrin [WD]) and reported their confidence in having ≥1 bowel movement (BM) every other day and their ability to predict timing of BMs after medication use, each on a 3-pt scale, and satisfaction with the medication's ability to relieve constipation symptoms on a 5-pt scale. Patient responses were analyzed by study drug and PCMs by comparing 12 week on-study averages and one-time screening responses using age-adjusted means. Results: Overall, 153 patients were treated with LIN 145, 159 with LIN 290, and 171 with placebo. Patients reporting each type of PCM numbered from 13 (WD) to 91 (SL). LIN 145-treated patients were statistically significantly (α = 0.05) more confident in having ≥1 BM every other day compared with those who reported using BL, SS, & WD prior to study start; LIN 290-treated patients were significantly more confident than those who reported use of BL & WD (Fig 1). Predictability of timing of BM after medication use was significantly better for LIN 145 compared with BL, LUBI, SL, SS, & WD and for LIN 290 compared with BL, PEG, SS, & WD (Fig 2). Satisfaction was significantly higher for LIN 145 compared with BL, SL, SS, & WD and for LIN 290 compared with BL, PEG, SS, & WD (Fig 3).Figure 1Figure 2Figure 3Conclusion: Although the trial was not powered for this analysis, patients reported LIN as being significantly better than 2-3 PCMs in confidence of having ≥1 BM every other day and better than 4-5 PCMs in predictability of BM timing after medication use. Patients reported significantly higher satisfaction in the ability of LIN to relieve constipation symptoms in comparison to 4 PCMs.