Lubiprostone for Pediatric Functional Constipation: Randomized, Controlled, Double-Blind Study With Long-term Extension.

BACKGROUND & AIMS: Pediatric functional constipation (PFC) is a common problem in children that causes distress and presents treatment challenges to health care professionals. We conducted a randomized, placebo-controlled trial (study 1) in patients with PFC (6-17 years of age) to evaluate the efficacy and safety of lubiprostone, followed by an open-label extension for those who completed the placebo-controlled phase (study 2). METHODS: Study 1 (NCT02042183) was a phase 3, multicenter, randomized, double-blind, placebo-controlled, 12-week study evaluating the efficacy and safety of lubiprostone 12 µg twice daily (BID) and 24 µg BID. Study 2 (NCT02138136) was a phase 3, long-term, open-label extension of study 1. In both studies, lubiprostone doses were based on patients' weight. Efficacy was assessed solely based on study 1, with a primary endpoint of overall spontaneous bowel movement (SBM) response (increase of ≥1 SBM/wk vs baseline and ≥3 SBMs/wk for ≥9 weeks, including 3 of the final 4 weeks). RESULTS: 606 patients were randomized to treatment (placebo: n = 202; lubiprostone: n = 404) in study 1. No statistically significant difference in overall SBM response rate was observed between the lubiprostone and placebo groups (18.5% vs 14.4%; P = .2245). Both the 12-µg BID and 24-µg BID doses of lubiprostone were well tolerated in the double-blind and extension phases, with a safety profile consistent with that seen in adult studies. CONCLUSIONS: Lubiprostone did not demonstrate statistically significant effectiveness over placebo in children and adolescents with PFC but did demonstrate a safety profile similar to that in adults. (ClinicalTrials.gov: Number: NCT02042183; Number: NCT02138136).

Safety of Lubiprostone in Pediatric Patients With Functional Constipation: A Nonrandomized, Open-Label Trial.

OBJECTIVES: Pediatric functional constipation (PFC) affects up to 30% of children. Current treatments often do not sustain symptomatic relief. Lubiprostone is a locally acting chloride channel activator that promotes fluid secretion into the small bowel without affecting serum electrolyte concentrations. We assessed the safety/tolerability of oral lubiprostone as treatment for PFC in a 24-week study. METHODS: This phase 3 open-label safety trial conducted from April-November 2016 at 13 US sites included patients (ages 6-17 years) diagnosed with PFC (Rome III criteria). Patients <50 and ≥50 kg received lubiprostone 12 or 24 mcg twice daily, respectively, for 24 weeks. Safety endpoints included incidence of treatment-emergent adverse events (TEAEs) and changes from baseline in clinical laboratory parameters and vital signs. RESULTS: Overall, 87 patients receiving lubiprostone, 64.3% (36/56) in the 12-mcg group and 54.8% (17/31) in the 24-mcg group, completed the study. Of 12 TEAEs leading to discontinuation, only upper abdominal pain occurred in >1 patient. TEAEs were mostly mild in intensity, with gastrointestinal disorders (diarrhea, vomiting) most frequently reported. No safety concerns were found in vital signs, abbreviated physical examinations, and laboratory tests. Subgroup analyses assessed an impact of age, sex, and race categories on TEAEs and treatment-related adverse events. Mean investigators' assessments of treatment effectiveness (scale of 0-4) for lubiprostone 12- and 24-mcg groups, respectively, were 2.8 and 2.9 at week 12, and 2.7 and 2.2 at week 24. CONCLUSIONS: Lubiprostone was well tolerated in the pediatric population. The incidence of TEAEs was comparable to that observed in previous clinical trials and in adults.

Capsule and Sprinkle Formulations of Lubiprostone Are Not Biologically Similar in Patients with Functional Constipation.

INTRODUCTION: Lubiprostone capsules are approved for managing three different chronic constipation conditions. A "sprinkle" formulation may facilitate use in individuals with difficulty swallowing capsules. Our objective was to evaluate the bioequivalence, pharmacokinetics (PK), and bioavailability of lubiprostone sprinkles vs lubiprostone capsules, compared with placebo. METHODS: A 1-week randomized, placebo-controlled, double-blinded, bioequivalence study (study 302) and a single-dose PK and bioavailability crossover study (study 304) were conducted. In study 302, 522 subjects with chronic constipation were randomized to lubiprostone sprinkle 24 µg twice daily (BID), lubiprostone capsule 24 µg BID, or placebo. The primary efficacy endpoint was observed spontaneous bowel movement (SBM) counts (equivalence defined as showing the 90% confidence interval [CI] of the "between-group SBM ratio" to be contained within 0.8-1.25). Study 304 included two cohorts of healthy volunteers randomized to a single 48-µg lubiprostone dose, sprinkle, or capsule (n = 35) or to a single 48-µg sprinkle dose, in fed or fasted state (n = 14). RESULTS: Both lubiprostone formulations significantly improved SBM count (sprinkle, 4.82 ± 3.66, P = 0.002; capsule, 5.74 ± 3.79, P < 0.0001) vs placebo (3.68 ± 2.16), but equivalent efficacy was not demonstrated, with a 90% CI for the SBM count ratio of 0.69-0.95. Quantifiable PK data on lubiprostone were limited; however, overall exposure to the M3 metabolite was approximately 44% higher with sprinkles vs capsules under fasted conditions (geometric mean ratio 1.441 [90% CI, 1.166, 1.782]), and exposure with the sprinkle formulation was 11% lower in the fed state vs the fasted state (geometric mean ratio 0.888 [90% CI, 0.675, 1.168]). Both formulations were generally well tolerated. CONCLUSION: Despite the significant improvement in SBM counts vs placebo, the sprinkle formulation did not demonstrate bioequivalence to the capsule formulation in either pharmacodynamic or PK key parameters. TRIAL REGISTRATION: Study 302: ClinicalTrials.gov identifier, NCT03097861; https://www.clinicaltrials.gov/ct2/show/NCT03097861 ; Study 304: ClinicalTrials.gov identifier, NCT03010631; https://www.clinicaltrials.gov/ct2/show/NCT03010631 .

Efficacy of Lubiprostone for the Treatment of Opioid-Induced Constipation, Analyzed by Opioid Class.

Objectives: To examine the efficacy and safety of lubiprostone for the treatment of opioid-induced constipation (OIC) in patients by opioid class received. Design: Data were pooled from three phase III, randomized, double-blind, placebo-controlled studies. Subjects/Setting: Adults with chronic noncancer pain receiving opioid therapy for 30 or more days and diagnosed with OIC. Methods: Overall mean change from baseline in spontaneous bowel movement (SBM) frequency, overall treatment response (≥1 SBM/week improvement over baseline SBM frequency in all treatment weeks with available data and ≥3 SBMs/week for ≥9 of the 12 weeks of treatment), and OIC-related symptoms were examined in patients taking opioids. Data were pooled and analyzed by opioid group. Results: In patients receiving phenanthrene opioids (e.g., oxycodone; N = 1,159), lubiprostone significantly increased overall mean changes in SBM frequency from baseline (P = 0.0001), increased overall response rate (P = 0.0024), and improved OIC symptoms (P ≤ 0.0229) vs placebo. Patients receiving phenylpiperidine opioids (e.g., fentanyl; N = 137) had significant improvement in SBM frequency (P = 0.0129) and favorable trends in response rates (21.4% vs 9.8%; P = 0.0723) and OIC symptoms vs placebo. Efficacy was not observed in overall analyses of patients receiving diphenylheptane opioids (e.g., methadone), although an increase in SBM frequency was observed in patients who received a morphine-equivalent daily dose of 200 or fewer mg, suggesting a dose-dependent negative interference of this opioid class on lubiprostone effects. For all groups, the lubiprostone adverse event profile was similar; the most common treatment-emergent adverse events were nausea and diarrhea. Conclusions: In patients using commonly prescribed opioids, lubiprostone is effective and generally well tolerated for the treatment of OIC.

Efficacy and Safety of Lubiprostone in Patients with Opioid-Induced Constipation: Phase 3 Study Results and Pooled Analysis of the Effect of Concomitant Methadone Use on Clinical Outcomes.

Objective: The efficacy and safety of oral lubiprostone for relieving symptoms of opioid-induced constipation (OIC) in patients with chronic noncancer pain were evaluated in a randomized, double-blind, placebo-controlled study. These data were also pooled with those from two similar phase 3 studies to explore the effects of methadone on treatment response. Methods: In the primary study, adults with OIC (fewer than three spontaneous bowel movements [SBMs] per week) were randomized to receive lubiprostone 24 mcg or placebo twice daily for 12 weeks. The primary end point was a change from baseline in the frequency of SBMs at week 8 in patients without a prior dose reduction. For the pooled analysis, the efficacy of lubiprostone was compared with placebo in patients receiving methadone or nonmethadone opioids. Responders were defined as patients with nine or more weeks of nonmissing SBM data who had one or more additional SBMs per week from baseline for each week that data were available and three or more SBMs per week for nine or more weeks. Results: In the primary study, the change from baseline at week 8 in SBM frequency was similar in the lubiprostone and placebo groups (P = 0.842). In the pooled analysis, the response rate was significantly higher with lubiprostone treatment vs placebo for patients receiving nonmethadone opioids (P = 0.002) but was similar between lubiprostone treatment and placebo in patients receiving methadone (P = 0.692). The safety profile of lubiprostone was unaffected by methadone use. Conclusions: The phase 3 study did not meet its primary efficacy end point. However, analysis of pooled data from all phase 3 studies in the OIC clinical development program, stratified by methadone opioid usage, confirmed that lubiprostone is effective for treatment of OIC in patients taking nonmethadone opioids; no safety concerns were identified based on the type of opioid used.

Lubiprostone for Opioid-Induced Constipation Does Not Interfere with Opioid Analgesia in Patients with Chronic Noncancer Pain.

OBJECTIVE: To determine whether lubiprostone 24 µg twice daily (BID), administered to relieve opioid-induced constipation (OIC), affects opioid analgesia in patients with chronic noncancer pain. METHODS: Data were pooled from 3 randomized, double-blind, placebo-controlled trials of lubiprostone in adults with chronic noncancer pain receiving stable opioid analgesia and who had documented OIC. In each study, lubiprostone 24 µg BID or placebo was administered for 12 weeks for relief of OIC using a common protocol. The Brief Pain Inventory short form (BPI-SF) was administered, and opioid use (expressed as morphine-equivalent daily dose [MEDD]) was recorded at baseline and months 1, 2, and 3. The BPI-SF provided patient scores for pain severity, the worst pain experienced in the past 24 hours, and pain interference with daily life. RESULTS: The pooled patient population (N = 1300) was predominately female (62.5%) and white (82.1%), with a mean age of 50.5 years. The MEDD was 97.5 mg (range, 5 to 3656 mg) in patients receiving placebo and 112.5 mg (range, 4 to 7605 mg) in patients treated with lubiprostone. Lubiprostone 24 µg BID treatment did not appear to affect opioid use or pain scores; changes from baseline were not significantly different with placebo vs. lubiprostone 24 µg BID at months 1, 2, and 3 for MEDD (P ≥ 0.435) and for BPI-SF scores for pain interference, pain severity, and worst pain (P ≥ 0.402). DISCUSSION: Lubiprostone 24 µg BID administered for relief of OIC in patients with chronic noncancer pain does not interfere with opioid analgesia.

Rifaximin therapy for patients with irritable bowel syndrome without constipation.

BACKGROUND: Evidence suggests that gut flora may play an important role in the pathophysiology of the irritable bowel syndrome (IBS). We evaluated rifaximin, a minimally absorbed antibiotic, as treatment for IBS. METHODS: In two identically designed, phase 3, double-blind, placebo-controlled trials (TARGET 1 and TARGET 2), patients who had IBS without constipation were randomly assigned to either rifaximin at a dose of 550 mg or placebo, three times daily for 2 weeks, and were followed for an additional 10 weeks. The primary end point, the proportion of patients who had adequate relief of global IBS symptoms, and the key secondary end point, the proportion of patients who had adequate relief of IBS-related bloating, were assessed weekly. Adequate relief was defined as self-reported relief of symptoms for at least 2 of the first 4 weeks after treatment. Other secondary end points included the percentage of patients who had a response to treatment as assessed by daily self-ratings of global IBS symptoms and individual symptoms of bloating, abdominal pain, and stool consistency during the 4 weeks after treatment and during the entire 3 months of the study. RESULTS: Significantly more patients in the rifaximin group than in the placebo group had adequate relief of global IBS symptoms during the first 4 weeks after treatment (40.8% vs. 31.2%, P=0.01, in TARGET 1; 40.6% vs. 32.2%, P=0.03, in TARGET 2; 40.7% vs. 31.7%, P<0.001, in the two studies combined). Similarly, more patients in the rifaximin group than in the placebo group had adequate relief of bloating (39.5% vs. 28.7%, P=0.005, in TARGET 1; 41.0% vs. 31.9%, P=0.02, in TARGET 2; 40.2% vs. 30.3%, P<0.001, in the two studies combined). In addition, significantly more patients in the rifaximin group had a response to treatment as assessed by daily ratings of IBS symptoms, bloating, abdominal pain, and stool consistency. The incidence of adverse events was similar in the two groups. CONCLUSIONS: Among patients who had IBS without constipation, treatment with rifaximin for 2 weeks provided significant relief of IBS symptoms, bloating, abdominal pain, and loose or watery stools. (Funded by Salix Pharmaceuticals; ClinicalTrials.gov numbers, NCT00731679 and NCT00724126.).

Safety and efficacy of a new 3.3 g b.i.d. tablet formulation in patients with mild-to-moderately-active ulcerative colitis: a multicenter, randomized, double-blind, placebo-controlled study.

OBJECTIVES: To evaluate the safety and efficacy of a new twice-daily balsalazide disodium 1.1 g tablet dosing regimen (6.6 g/day, three tablets twice daily) for the treatment of mild-to-moderately-active ulcerative colitis (UC). METHODS: In a double-blind, multicenter study patients with symptoms of acute UC and a baseline Modified Mayo Disease Activity Index (MMDAI) score between 6 and 10, inclusive, with a subscale rating of > or =2 for both rectal bleeding and mucosal appearance were randomized to receive 3.3 g of balsalazide or placebo tablets twice daily for 8 weeks. The primary end point was the proportion of patients achieving clinical improvement (> or =3 point improvement in MMDAI) and improvement in rectal bleeding (> or =1 point improvement) at 8 weeks. Safety assessments were conducted from baseline through 2-weeks post-treatment. RESULTS: A total of 249 patients (166 balsalazide, 83 placebo) received at least 1 dose of study medication. The mean MMDAI score at baseline was 7.9; 62% of patients had a score > or =8.0 (moderate disease). A significantly larger proportion of patients achieved clinical improvement and improvement in rectal bleeding in the balsalazide group vs. the placebo group (55 vs. 40%, P=0.02). The most common adverse events reported were worsening of UC and headache; both were reported more often in the placebo group. CONCLUSIONS: Balsalazide disodium 1.1 g tablets administered as 3.3 g twice daily are effective, well tolerated and significantly better than placebo for improving signs and symptoms of mild-to-moderately-active UC. This new formulation with a reduced pill and dosing burden offers the potential to improve convenience and compliance in patients with active UC.