Study to Evaluate the Safety and Efficacy of ABT-712 in Subjects With Moderate to Severe Chronic Low Back Pain (CLBP)

Study Overview
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Brief Summary
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The primary purpose of the study is to test the efficacy of 2 tablets (twice daily) of ABT-712, compared to placebo, administered over a 4-week period in participants with moderate to severe mechanical chronic low back pain (CLBP).

Detailed Description
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The study used a randomized withdrawal design with an open label (OL) period prior to a double-blind (DB) period. Participants who were receiving benefit and were tolerating ABT-712 during the OL period were randomized into the DB period. Study drug was given for a total of 8 weeks, which included up to 3 weeks in OL, up to 4 weeks in DB, and a 1-week DB taper. During the OL period, all participants took increasing doses of ABT-712 until they were taking 2 tablets, twice daily. During the DB period, participants in the ABT-712 group took 2 ABT-712 tablets, twice daily throughout the 4 weeks, while participants in the placebo group took 2 placebo tablets twice daily.

Official Title
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A Phase 3, Open-Label Period Followed by a Randomized, Double-blind Placebo-controlled Study of the Analgesic Efficacy of Extended-release Hydrocodone/Acetaminophen (Vicodin CR) Compared to Placebo in Subjects With Chronic Low Back Pain

Conditions
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Chronic Low Back Pain

Intervention / Treatment
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* Drug: ABT-712
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult male and female subjects who voluntarily sign the informed consent Diagnosis of CLBP of 6 months duration Exclusion Criteria: Incapacitated or bedridden subjects Subjects with history of surgical or invasive intervention

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 75 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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Open-label ABT-712<br>2 ABT-712 extended-release tablets, twice daily, for up to 3 weeks (open-label period). | Drug: ABT-712<br>* ABT-712 extended-release tablet<br>* Other names: Hydrocodone bitartrate and acetaminophen extended-release;|
| Experimental: Double-blind ABT-712<br>2 ABT-712 extended-release tablets, twice daily, for 4 weeks (double-blind period). | Drug: ABT-712<br>* ABT-712 extended-release tablet<br>* Other names: Hydrocodone bitartrate and acetaminophen extended-release;|
| Placebo Comparator: Double-blind Placebo<br>2 placebo tablets, twice daily, for 4 weeks (double-blind period). | Drug: Placebo<br>* Placebo tablet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Double-blind (DB) Baseline to Final Assessment in Chronic Lower Back Pain (CLBP) Intensity by Visual Analog Scale (VAS) | The change from the DB randomization baseline (DB baseline: the last assessment before first dose in the DB period) to the final assessment in pain intensity, assessed using the CLBP Intensity VAS (0 mm = No Pain and 100 mm = Worst Pain Imaginable). Least squares means and standard errors from 2-way ANCOVA model without interaction. | Double-blind baseline to 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Double-blind (DB) Baseline to Final Assessment in Chronic Pain Sleep Inventory (CPSI) | The change from the DB randomization baseline (DB baseline: the last assessment before first dose in the DB period) to the final assessment of the impact of pain on the participant's sleep. The CPSI utilizes a 100 mm VAS scale for questions of how often the participant had trouble falling asleep because of pain, needed sleeping medication, was awakened by pain during the night, and was awakened by pain in the morning (0 mm = Never and 100 mm = Always); and for rating the overall quality of sleep (0 mm = Very Poor and 100 mm = Excellent). Least squares means and standard errors from 2-way ANCOVA model without interaction. | Double-blind baseline to 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Effect on sleep interference by pain