Cost Effectiveness of Naloxegol for Opioid-Induced Constipation in the UK.

BACKGROUND AND OBJECTIVES: Opioid-induced constipation (OIC) is the most common adverse effect reported in patients receiving opioids to manage pain. Initial treatment with laxatives provides inadequate response in some patients. Naloxegol is a peripherally acting µ-opioid receptor antagonist used to treat patients with inadequate response to laxative(s) (laxative inadequate responder [LIR]). A cost-effectiveness model was constructed from the UK payer perspective to compare oral naloxegol 25 mg with placebo in non-cancer LIR patients receiving opioids for chronic pain, and a scenario analysis of naloxegol 25 mg with rescue laxatives compared with placebo with rescue laxatives in the same patient population. METHODS: The model comprised a decision tree for the first 4 weeks of treatment, followed by a Markov model with a 4-week cycle length and the following states: 'OIC', 'non-OIC (on treatment)', 'non-OIC (untreated)' and 'death'. Two phase III trials with a follow-up period of 12 weeks provided data on treatment efficacy, transition probabilities, adverse event frequency and patient utility. Resource utilisation data were sourced from a UK-based burden of illness study and physician surveys. A UK National Health Service and Personal Social Service perspective was adopted; costs and health-related quality of life gains were discounted at a rate of 3.5 %. The model was run over a time horizon of 5 years, reflecting the average period of opioid use. RESULTS: Naloxegol has an incremental cost-effectiveness ratio of £10,849 per quality-adjusted life-year gained versus placebo, and £11,179 when rescue laxatives are made available in both arms (2014 values). Model outcomes were only sensitive to variations in utility inputs. However, the probabilistic sensitivity analyses indicate that naloxegol has a 91 % probability of being cost effective at a £20,000 threshold when compared with placebo. CONCLUSIONS: Naloxegol is likely a cost-effective treatment option for LIR patients with OIC. This assessment should be supported by further work on the utility of patients with OIC, including how utility varies with more granular measures of OIC.

Opioid-Induced Constipation among a Convenience Sample of Patients with Cancer Pain.

BACKGROUND: Little is known regarding the burden of opioid-induced constipation (OIC) among patients who suffer from cancer-related pain. METHODS: A prospective longitudinal study was conducted among cancer patients in the United Kingdom (UK), Canada, and Germany, which included medical record data abstraction, Internet-based patient surveys, and physician surveys. Patients on daily opioid therapy (≥30 mg for ≥4 weeks) for treatment of cancer pain with self-reported OIC were recruited. Response to laxatives was defined by classifying participants into categories of laxative use and evaluating the prevalence of inadequate response. Descriptive statistics were used to evaluate outcomes, including the patient assessment of constipation-symptom (PAC-SYM), patient assessment of constipation-quality of life, EuroQOL-5 dimensions, and global assessment of treatment benefit, satisfaction, and willingness to continue. RESULTS: Recruitment was difficult for this study with only 31 participants completing the baseline survey and meeting criteria for opioid use and OIC (26 UK, 1 Canada, and 4 Germany). Fifty-two percent (n = 16) of participants were male, and all were White. Breast (23%, n = 7), pancreatic (13%, n = 4), and multiple myeloma (13%, n = 4) were the most common cancers. Mean duration of chronic pain and opioid use were 2.3 and 1.3 years, respectively. Participants reported having a mean of 4.4 bowel movements/week in the 2 weeks prior to baseline, of which a mean of 0.9 were spontaneous. Most participants (90%, n = 28) were using at least 1 lifestyle approach to manage their constipation; 65% (n = 20) were taking ≥1 over-the-counter laxative; 19% (n = 6) were taking ≥1 prescription laxative; 23% (n = 7) reported no laxative use in the prior 2 weeks. Moderate-to-severe constipation symptoms on the PAC-SYM were common, and mean scores on health-related quality of life outcomes were comparable to chronic pain populations. CONCLUSION: In this primarily UK sample, there appears to be considerable unmet OIC treatment needs among cancer patients.

Impact of Treatment with Naloxegol for Opioid-Induced Constipation on Patients' Health State Utility.

INTRODUCTION: Opioid-induced constipation (OIC) is the most common side effect of opioid treatment. Treatment for OIC typically involves a laxative. However, some patients have an inadequate response to these (laxative inadequate responders, or LIR). This has led to the development of treatments such as naloxegol. This analysis estimates the impact of naloxegol on the health state utility of LIR patients, examines if this utility impact is driven by the change in OIC status, and estimates the utility impact of relief of OIC. METHODS: The analysis was conducted using data from two 12-week randomized controlled trials, KODIAC 4 (ClinicalTrials.gov identifier, NCT01309841) and KODIAC 5 (ClinicalTrials.gov identifier, NCT01323790), plus KODIAC 7 (ClinicalTrials.gov identifier, NCT01395524), a 12-week extension to KODIAC 4. All were designed to assess the efficacy and safety of oral naloxegol (12.5 and 25 mg) compared to placebo. Health state utility data were collected through the EuroQol-five dimensions questionnaire (EQ-5D-3L). Descriptive analysis was undertaken to estimate how EQ-5D utility scores and EQ-5D domain responses varied with treatment, OIC status, and over time. A repeated measure mixed-effects model was used to predict the change from baseline in health state utility score over time. RESULTS: Compared with placebo, LIR patients treated with naloxegol 25 mg reported a 0.08 improvement in the EQ-5D overall score after 12 weeks of treatment. The analyses also suggest that change in OIC status is a key driver of the impact of OIC treatment on health state utility. When other factors are controlled, relieving OIC is associated with a 0.05 improvement in health state utility, although treatment with naloxegol is associated with an improvement in health state utility over and above the improvement in OIC status. CONCLUSION: These analyses suggest that treatment with naloxegol improves patients' health state utility; driven predominantly by the relief of patients' constipation. FUNDING: AstraZeneca.

Opioid-Induced Constipation Among Patients with Chronic Noncancer Pain in the United States, Canada, Germany, and the United Kingdom: Laxative Use, Response, and Symptom Burden Over Time.

PURPOSE: Estimate rate of laxative inadequate response (LIR) over time among patients with chronic noncancer pain with opioid-induced constipation (OIC). METHODS: A prospective longitudinal study was conducted in United States, Canada, Germany, and United Kingdom. Patients on opioid therapy for ≥4 weeks for chronic noncancer pain and OIC completed an Internet-based survey at Baseline and Weeks 2, 4, 6, 8, 12, 16, 20, and 24. 1xLIR was defined as sufficient laxative use (≥1 laxative ≥ 4 times in past 2 weeks) and inadequate response (<3 bowel movements or ≥ 1 constipation symptom rated Moderate or greater). 2xLIR was sufficient laxative use of ≥2 laxatives from different drug classes and inadequate response. Descriptive statistics and logistic regressions were performed. RESULTS: 489 patients (62% female; 85% white) completed Baseline; 27% reported no laxative use; 25% had insufficient laxative use; 48% had sufficient laxative use. During follow-up, 21-28% of patients had no or insufficient laxative use. Prevalence of 1xLIR was 93% at Baseline and ranged from 59-81% across follow-up; 26% met criteria for 2xLIR (follow-up range: 11-20%). CONCLUSIONS: OIC among noncancer pain patients is a persistent and significant condition with varying utilization and response to laxatives thus increasing the ongoing burden of chronic pain. © 2014 Wiley Periodicals, Inc.