Evaluation of the Efficacy and Safety of Lubiprostone in Adults With Mixed or Unsubtyped Irritable Bowel Syndrome

Study Overview
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Brief Summary
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A study of the efficacy and safety of Lubiprostone in subjects diagnosed with IBS-M/IBS-U.

Detailed Description
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To assess the efficacy and safety of oral lubiprostone, as compared to matching placebo, when administered orally (at 8 mcg twice daily [BID]) in subjects diagnosed with IBS-M/IBS-U.

Official Title
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A Randomized, Double-blind, Placebo-Controlled, Multicenter Study of the Efficacy and Safety of Lubiprostone in Adult Subjects With Mixed or Unsubtyped Irritable Bowel Syndrome (IBS-M/IBS-U)

Conditions
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Irritable Bowel Syndrome

Intervention / Treatment
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* Drug: Lubiprostone
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject meets the diagnosis of IBS-M or IBS-U as confirmed using the adapted ROME III Diagnostic Questionnaire for Adult Functional GI Disorders. Subject Screening diary entries must show an average worst abdominal pain in the past 24 hours score of at least 4 on a 11-point scale. Subject must be on a stable dose of selective serotonin re-uptake inhibitors (SSRIs), serotonin-specific reuptake inhibitor (SNRIs), or monoamine oxidase inhibitors (MAO) inhibitors if taking antidepressants. Exclusion Criteria: Subject has current diagnosis of IBS with diarrhea (IBS-D) or IBS with constipation (IBS-C), according to Rome III Criteria. Any gastrointestinal (GI) condition, other than IBS-related, affecting GI motility or defecation. Medical/surgical condition that might interfere with the absorption, distribution, metabolism, or excretion of the study medication.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lubiprostone<br>Participants receive 8 mcg lubiprostone capsules twice daily (BID) | Drug: Lubiprostone<br>* 8 mcg administered orally twice daily (BID)<br>* Other names: Amitiza;|
| Placebo Comparator: Placebo<br>Participants receive 0 mcg capsules BID | Drug: Placebo<br>* Matching placebo, 0 mcg administered orally twice daily (BID)<br>* Other names: Matching Placebo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Classified as an Overall Responder for Abdominal Pain | An overall responder for abdominal pain is defined as a participant who is a weekly responder for at least 75% of observed treatment weeks. | within 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Classified as a Weekly Responder for Abdominal Pain | Participants rate their pain on a pain intensity scale where 0=no pain and 10=worst pain. A higher score means the pain is worse. A weekly responder for abdominal pain is defined as a participant reporting ≥ 30% reduction from baseline in average of 24-hour worst abdominal pain scores for the preceding week. | within 12 weeks | 
| Number of Participants Classified as a Monthly Responder for Abdominal Pain | A monthly responder for abdominal pain is defined as a participant who is a weekly responder for abdominal pain at least 2 of 4 weeks in the preceding month. | within 3 months | 
| Number of Participants Classified as a Weekly Responder for Stool Consistency | A weekly responder for stool consistency is defined as a participant having at least 50% reduction from baseline in percentage of days with extreme stool consistency for a given week. | within 12 weeks | 
| Number of Participants Classified as a Monthly Responder for Stool Consistency | A monthly responder for stool consistency is defined as a participant who is a weekly responder for stool consistency at least 2 of 4 weeks in the preceding month. | within 3 months | 
| Number of Participants Classified as an Overall Responder for Stool Consistency | An overall responder for stool consistency is defined as a participant who qualifies as a weekly responder for stool consistency for at least 75% of observed treatment weeks. | within 3 months | 
| Number of Participants Classified as a Weekly Responder for Irritable Bowel Syndrome (IBS) Symptoms | A participant who achieves adequate relief of IBS symptoms during the preceding week is classified as a weekly responder for IBS symptoms. | within 12 weeks | 
| Number of Participants Classified as a Monthly Responder for IBS Symptoms | A participant who is a weekly responder for IBS symptoms for at least 2 of the 4 weeks in the preceding month is classified as a monthly responder for IBS symptoms. | within 3 months | 
| Number of Participants Classified as an Overall Responder for IBS Symptoms | A participant who is a weekly responder for IBS symptoms for at least 75% of observed treatment weeks is classified as an overall responder for IBS symptoms. | within 3 months |