Study to Evaluate the Efficacy and Safety of Hydrocodone Bitartrate Extended-Release Tablets (CEP-33237) for Relief of Moderate to Severe Pain in Patients With Osteoarthritis or Low Back Pain Who Require Opioid Treatment for an Extended Period of Time

Chronic Pain Clinical Trial

Official title:

A 12-Week, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Hydrocodone Bitartrate Extended-Release Tablets (CEP-33237) at 15 to 90 mg Every 12 Hours for Relief of Moderate to Severe Pain in Patients With Osteoarthritis or Low Back Pain Who Require Opioid Treatment for an Extended Period of Time

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01240863
• Other study ID #: C33237/3079
• Status: Completed
• Phase: Phase 3
• First received: November 10, 2010
• Last updated: June 2, 2017
• Start date: November 2010
• Est. completion date: August 2011

Study information

• Verified date: June 2017
• Source: Teva Pharmaceutical Industries
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The primary objective of this study is to evaluate efficacy of hydrocodone extended-release (ER) tablets compared with placebo in alleviating moderate to severe pain in patients with osteoarthritis or low back pain as assessed by the weekly Average Pain Intensity (API) at week 12.

Description:

The study consisted of a screening period of approximately 7 to 14 days, an open label titration period of up to 6 weeks, and a double blind treatment period of 12 weeks.

Participants entered the open label titration period and received hydrocodone ER tablets beginning with 15 mg every 12 hours for 3 to 7 days. The objective of the open label titration period was to find the successful dose of hydrocodone ER tablets that produced stable pain relief (defined as an Average Pain Intensity (API) score of 4 or less on the 11-point numerical rating scale for either 3 consecutive days or 3 out of 5 consecutive days while the patient was maintained on the same dose of study drug for up to 7 days). Patients returned to the study center prior to each dose adjustment.

Participants who met the criterion of a stabilized dose were randomly assigned into the 12 week, double blind, placebo controlled treatment period on the final day of the open label titration period (baseline visit). Patients began treatment with double blind study drug at the effective dose of hydrocodone ER tablets achieved during the titration period or matching placebo. Rescue medication was permitted in addition to the study drug during the double blind treatment period.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 391
• Est. completion date: August 2011
• Est. primary completion date: August 2011
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• The patient is able to speak English and is willing to provide written informed consent, including a written opioid agreement, to participate in this study.

• The patient must be willing and able to successfully self-administer the study drug, comply with study restrictions, complete the electronic diary, and return to the clinic for scheduled study visits as specified in this protocol.

• Women of childbearing potential (not surgically sterile or 2 years postmenopausal), must use a medically accepted method of contraception and must agree to continue use of this method for the duration of the study and for 30 days after participation in the study, and have a negative pregnancy test at screening.

• The patient has pain of at least 3 months' duration associated with osteoarthritis or low back pain.

• The patient reports an average pain intensity score, over the prior 24 hours, of 5 or more on the 11-point numerical rating scale.

• If the patient is receiving physical therapy, biofeedback therapy, acupuncture therapy, or herbal remedies, these therapies must remain unchanged during the study.

• The patient must not participate in other study involving an investigational agent while enrolled into the present study.

Exclusion Criteria:

• The patient has known or suspected hypersensitivities, allergies, or other contraindications to any ingredient in the study drug.

• The patient has a recent history (within 5 years) or current evidence of alcohol or other substance abuse with the exception of nicotine or caffeine.

• The patient has medical or psychiatric disease that, in the opinion of the investigator, would compromise collected data.

• The patient is taking a total (ie, around-the-clock plus rescue medication) of more than 135 mg/day of oxycodone, or equivalent, during the 14 days prior to screening.

• The patient has a history of suicidality.

• The patient is expected to have surgery during the study.

• The patient's primary painful condition under study is related to any source of chronic pain other than osteoarthritis or low back pain.

• The patient is pregnant or lactating.

• The patient has active malignancy.

• The patient has human immunodeficiency virus (HIV).

• In the judgment of the investigator, the patient has any clinically significant deviation from normal in the physical examination and/or clinical laboratory test values.

• The patient has cardiopulmonary disease that would, in the opinion of the investigator, significantly increase the risk of treatment with opioids.

• The patient has participated in a study involving an investigational drug in the previous 30 days.

• The patient has received a monoamine oxidase inhibitor (MAOI) within 14 days before the first treatment with study drug.

• The patient has any other medical condition or is receiving concomitant medication/therapy (e.g., regional nerve block) that would, in the opinion of the investigator, compromise the patient's safety or compliance with the study protocol, or compromise collected data.

• The patient is involved in active litigation in regard to the pain currently being treated.

• The patient has a positive urine drug screen (UDS) that is not medically explainable.

• The investigator feels that the patient is not suitable for the study for any reason.

Related Conditions & MeSH terms

• Back Pain
• Chronic Pain
• Low Back Pain
• Osteoarthritis

Intervention

Drug:
• Hydrocodone ER
During the open-label, titration period, all participants were administered hydrocodone ER tablets at dosages of 15, 30, 45, 60, or 90 mg every 12 hours to identify a dosage deemed successful for managing their pain. Hydrocodone ER was taken by participants randomized to the hydrocodone ER treatment arm during the double-blind treatment period at the dose level identified during the titration period. Participants were instructed to take tablets with a glass of water on an empty stomach at least 1 hour before or 2 hours after eating.
• Placebo
Placebo matching the active drug dose identified during the titration period was taken by participants randomized to the placebo treatment arm during the double-blind treatment period. Participants were instructed to take intervention with a glass of water on an empty stomach at least 1 hour before or 2 hours after eating.

Locations

Country	Name	City	State
United States	Radiant Research, Inc	Akron	Ohio
United States	Physician Alliance Research Center	Anaheim	California
United States	Radiant Research Inc.	Anderson	South Carolina
United States	Horizon Research Group, LLC	Baton Rouge	Louisiana
United States	Millennium Pain Center	Bloomington	Illinois
United States	Beacon Clinical Research, LLC	Brockton	Massachusetts
United States	Associated Pharmaceutical Research Center, Inc.	Buena Park	California
United States	Providence Clinical Research	Burbank	California
United States	Radiant Research, Inc.	Chandler	Arizona
United States	Medex Healthcare Research, Inc.	Chicago	Illinois
United States	Community Research, Inc	Cincinnati	Ohio
United States	Community Research, Inc	Cincinnati	Ohio
United States	Sterling Research Group, Ltd.	Cincinnati	Ohio
United States	Clinical Research of West Florida, Inc.	Clearwater	Florida
United States	Rapid Medical Research	Cleveland	Ohio
United States	Columbus Clinical Research	Columbus	Ohio
United States	Community Research	Crestview	Kentucky
United States	KRK Medical Research	Dallas	Texas
United States	Radiant Research Dallas	Dallas	Texas
United States	Renaissance Clinical Research & Hypertension of Texas, PLLC	Dallas	Texas
United States	Avail Clinical Research, LLC	DeLand	Florida
United States	Radiant Research, Inc	Denver	Colorado
United States	Brandywine Clinical Research	Downingtown	Pennsylvania
United States	Synergy Clinical Research	Escondido	California
United States	Pain Research of Oregon	Eugene	Oregon
United States	HealthCare Research	Florissant	Missouri
United States	Research Center of Fresno, Inc.	Fresno	California
United States	Greenville Pharmaceutical Research	Greenville	South Carolina
United States	Radiant Research, Inc	Greer	South Carolina
United States	Medstar Clinical Research	Houston	Texas
United States	Rehabilitation Associates of Indiana	Indianapolis	Indiana
United States	Pacific Coast Pain Management Center	Laguna Hills	California
United States	South Orange County Surgical Medical Group	Laguna Hills	California
United States	Clinical Research Center of Nevada	Las Vegas	Nevada
United States	International Clinical Research, Inc.	Leawood	Kansas
United States	The Pain Treatment Center of the Bluegrass	Lexington	Kentucky
United States	Robert M. Karns, MD A Medical Corporation	Los Angeles	California
United States	Drug Studies America	Marietta	Georgia
United States	Georgia Institute for Clinical Research, LLC	Marietta	Georgia
United States	International Research Associates, LLC	Miami	Florida
United States	Horizon Research Group LLC	Mobile	Alabama
United States	Better Health Clinical Research, Inc.	Newnan	Georgia
United States	Trident Institute of Medical Research, LLC	North Charleston	South Carolina
United States	SP Research	Oklahoma City	Oklahoma
United States	Meridian Clinical Research	Omaha	Nebraska
United States	Aspen Clinical Research, LLC	Orem	Utah
United States	Compass Research	Orlando	Florida
United States	MidAtlantic Pain Medicine Center	Pikesville	Maryland
United States	Radiant Research, Inc.	Pinellas Park	Florida
United States	Gold Coast Research LLC	Plantation	Florida
United States	Summit Research Network Inc.	Portland	Oregon
United States	Wake Research Associates	Raleigh	North Carolina
United States	Medex Healthcare Research Inc.	Saint Louis	Missouri
United States	Sundance Clinical Research, LLC	Saint Louis	Missouri
United States	Lifetree Clinical Research	Salt Lake City	Utah
United States	Benchmark Research	San Angelo	Texas
United States	Accelovance, Inc.	San Diego	California
United States	Radiant Research, Inc.	Santa Rosa	California
United States	Sarasota Pain Medicine Research LLC	Sarasota	Florida
United States	Radiant Research, Inc.	Scottsdale	Arizona
United States	WK River Cities Clinical Research Center	Shreveport	Louisiana
United States	South Carolina Pharmaceutical Research	Spartanburg	South Carolina
United States	DCT-Sugarland, LLC	Sugar Land	Texas
United States	Clinical Research of West Florida, Inc.	Tampa	Florida
United States	Tipton Medical and Diagnostic Center	Tipton	Pennsylvania
United States	AMH Feasterville Family Health Care Center	Trevose	Pennsylvania
United States	Radiant Research Inc.	Tucson	Arizona
United States	Bayview Research Group, LLC	Valley Village	California
United States	Advanced Pain Consultants	Voorhees	New Jersey
United States	Hillcrest Family Health Centers	Waco	Texas
United States	Omega Medical Research	Warwick	Rhode Island
United States	Upstate Clinical Research Associates	Williamsville	New York
United States	Clinical Research Center of Reading	Wyomissing	Pennsylvania

Sponsors (1)

Lead Sponsor	Collaborator
Teva Branded Pharmaceutical Products, R&D Inc.

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change From Baseline to Week 12 in Weekly Average Pain Intensity (wAPI)	The primary efficacy variable was the change from baseline to week 12 in the wAPI. The API over the previous 24 hours, based on the 11-point Numerical Rating Scale (NRS 11), was collected daily by e-diary. The Week 12 wAPI scores from the previous 7 days were calculated for each study visit and averaged. The baseline wAPI score was calculated by averaging API scores from 3 to 12 days when the successful dose of hydrocodone extended release was confirmed at the end of the open label titration period, before patients were randomly assigned study drug. In the case of missing week-12 data due to early withdrawal from the study, or excessive rescue medication usage, the wAPI for week 12 was imputed.; The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain on a Likert-type scale in which 0 is no pain and 10 is the worst pain imaginable. Negative change from baseline values indicate lessening in pain intensity.	Baseline (end of Open-Label Titration Period), Week 12 of Double-blind Treatment Period
Secondary	Percentage of Participants Withdrawn From the Study During the Double-Blind Treatment Period By Reason	Percentage of participants who withdrew from the study during the double-blind treatment period. Withdrawal is due to any cause, including lack of efficacy.	Day 1 to Week 12 of the double-blind treatment period
Secondary	Kaplan-Meier Estimates for Time to Discontinuation From the Study	Kaplan-Meier estimates for time to discontinuation from the study (due to any cause) was calculated as the number of days since participants were randomly assigned to study drug treatment, ie, the difference between the date the participants withdrew and the date participants were randomly assigned to study drug treatment. The censoring flag was set to 0 if a participant was withdrawn from study drug treatment early and was set to 1 if the participant completed the 12 week treatment period. Censoring time was calculated as the difference of treatment completion date (ie, date of last study drug administration) and date participant was randomly assigned to study drug treatment.	Day 1 to Week 12 of the double-blind treatment period
Secondary	Participants With a Weekly Average Pain Intensity (wAPI) Increase From Baseline Exceeding 33%	The API over the previous 24 hours, based on the 11-point Numerical Rating Scale (NRS 11), was collected daily by e-diary. The wAPI scores from the previous 7 days were calculated for each study visit and averaged. The baseline wAPI score was calculated by averaging API scores from 3 to 12 days when the successful dose of hydrocodone extended release was confirmed at the end of the open label titration period, before patients were randomly assigned study drug.; The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain on a Likert-type scale in which 0 is no pain and 10 is the worst pain imaginable.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, and 12 of the Double-blind treatment period
Secondary	Participants With a Weekly Average Pain Intensity (wAPI) Increase From Baseline Exceeding 50%	The API over the previous 24 hours, based on the 11-point Numerical Rating Scale (NRS 11), was collected daily by e-diary. The wAPI scores from the previous 7 days were calculated for each study visit and averaged. The baseline wAPI score was calculated by averaging API scores from 3 to 12 days when the successful dose of hydrocodone extended release was confirmed at the end of the open label titration period, before patients were randomly assigned study drug.; The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain on a Likert-type scale in which 0 is no pain and 10 is the worst pain imaginable.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, and 12 of the Double-blind treatment period
Secondary	Weekly Average Pain Intensity (wAPI) Scores During the Double-blind Treatment Period	The API over the previous 24 hours, based on the 11-point Numerical Rating Scale (NRS 11), was collected daily by e-diary. The wAPI scores from the previous 7 days were calculated for each study visit and averaged. The baseline wAPI score was calculated by averaging API scores from 3 to 12 days when the successful dose of hydrocodone extended release was confirmed at the end of the open label titration period, before patients were randomly assigned study drug.; The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain on a Likert-type scale in which 0 is no pain and 10 is the worst pain imaginable.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, and 12 of the Double-blind treatment period
Secondary	Weekly Average Worst Pain Intensity (WPI) Scores During the Double-blind Treatment Period	The WPI was recorded by the patient in the e-diary daily throughout the study, based on the Numeric Rating Scale (NRS-11). Participants were asked to select the number that best described their WPI over the previous 24 hours. Values were averaged for each week.; The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain on a Likert-type scale in which 0 is no pain and 10 is the worst pain imaginable.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, and 12 of the Double-blind treatment period
Secondary	Clinician Assessment of Patient Function (CAPF) at Week 4	Clinicians assessed participants across 5 dimensions: Patients general activities; Patients walking ability; Patients ability to work/perform activities of daily living; Patients relationships with others; Patients enjoyment of life; Assessments are rated on a 7-point scale, in which 1 is very much worsened and 7 is very much improved since the start of the study.	Week 4 of the Double-blind Treatment Period
Secondary	Clinician Assessment of Patient Function (CAPF) at Week 8	Clinicians assessed participants across 5 dimensions: Patients general activities; Patients walking ability; Patients ability to work/perform activities of daily living; Patients relationships with others; Patients enjoyment of life; Assessments are rated on a 7-point scale, in which 1 is very much worsened and 7 is very much improved since the start of the study.	Week 8 of the Double-blind Treatment Period
Secondary	Clinician Assessment of Patient Function (CAPF) at Week 12	Clinicians assessed participants across 5 dimensions: Patients general activities; Patients walking ability; Patients ability to work/perform activities of daily living; Patients relationships with others; Patients enjoyment of life; Assessments are rated on a 7-point scale, in which 1 is very much worsened and 7 is very much improved since the start of the study.	Week 12 of the Double-blind Treatment Period
Secondary	Clinician Assessment of Patient Function (CAPF) at Endpoint	Clinicians assessed participants across 5 dimensions: Patients general activities; Patients walking ability; Patients ability to work/perform activities of daily living; Patients relationships with others; Patients enjoyment of life; Assessments are rated on a 7-point scale, in which 1 is very much worsened and 7 is very much improved since the start of the study.; Endpoint values are the last observed postbaseline data.	Endpoint of the Double-blind Treatment Period (up to week 12)
Secondary	Patient Assessment of Function (PAF) at Week 4	The PAF is a self-administered questionnaire used to measure patients' assessment of their own ability to function in normal activities. Answers to the 7 questions were rated on a 7 point scale in which 1 was very much worsened and 7 were very much improved since the start of the study.; The seven functional areas are: ability to go to work; ability to perform at work (includes both work outside the home and housework); ability to walk; ability to exercise; ability to participate in social events; ability to have sex; ability to enjoy life	Week 4 of the Double-blind Treatment Period
Secondary	Patient Assessment of Function (PAF) at Week 8	The PAF is a self-administered questionnaire used to measure patients' assessment of their own ability to function in normal activities. Answers to the 7 questions were rated on a 7 point scale in which 1 was very much worsened and 7 were very much improved since the start of the study.; The seven functional areas are: ability to go to work; ability to perform at work (includes both work outside the home and housework); ability to walk; ability to exercise; ability to participate in social events; ability to have sex; ability to enjoy life	Week 8 of the Double-blind Treatment Period
Secondary	Patient Assessment of Function (PAF) at Week 12	The PAF is a self-administered questionnaire used to measure patients' assessment of their own ability to function in normal activities. Answers to the 7 questions were rated on a 7 point scale in which 1 was very much worsened and 7 were very much improved since the start of the study.; The seven functional areas are: ability to go to work; ability to perform at work (includes both work outside the home and housework); ability to walk; ability to exercise; ability to participate in social events; ability to have sex; ability to enjoy life	Week 12 of the Double-blind Treatment Period
Secondary	Patient Assessment of Function (PAF) at Endpoint	The PAF is a self-administered questionnaire used to measure patients' assessment of their own ability to function in normal activities. Answers to the 7 questions were rated on a 7 point scale in which 1 was very much worsened and 7 were very much improved since the start of the study.; The seven functional areas are: ability to go to work; ability to perform at work (includes both work outside the home and housework); ability to walk; ability to exercise; ability to participate in social events; ability to have sex; ability to enjoy life; Endpoint values are the last observed postbaseline data.	Endpoint of the Double-blind Treatment Period (up to week 12)
Secondary	Clinician Global Impression of Severity (CGI-S) of Illness Scores During the Double-blind Treatment Period	The CGI-S is a clinician-rated scale that assesses the severity of the patient's pain condition and response to the treatment. Severity of illness, as related to moderate to severe pain, consists of the following 7 categories: 1 normal-shows no sign of illness,; 2 borderline ill,; 3 mildly (slightly) ill,; 4 moderately ill,; 5 markedly ill,; 6 severely ill, and; 7 among the most extremely ill (Guy 1976).; The clinician assesses the severity of the patient's condition, based on the clinician's total clinical experience with patients with this condition, in response to treatment.; Endpoint values are the last observed postbaseline data.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, and 12 of the Double-blind treatment period
Secondary	Short-Form Health Survey (SF-36) Physical and Mental Component Summary Scores at Baseline, Week 12 and Endpoint	SF-36 is a generic 36-item questionnaire measuring health-related quality of life (HRQL) covering 2 summary measures: physical component summary (PCS) and mental component summary (MCS). The SF-36 consists of 8 subscales. The PCS is represented by 4 subscales: physical function, role limitations due to physical problems, pain, and general health perception. The MCS is represented by 4 subscales: vitality, social function, role limitations due to emotional problems, and mental health. Participants self-report on items in a subscale that have between 2-6 choices per item using Likert-type responses (e.g. none of the time, some of the time, etc.). PCS and MCS scores are constructed as a T-score with a mean of 50 and standard deviation of 10 and no minimum or maximum score; higher scores indicate better health status.	Baseline (end of Open-Label Titration Period), Week 12 and Endpoint (last visit up to week 12) of the Double-blind treatment period
Secondary	Brief Pain Inventory - Short Form (BPI-SF) Pain Interference Mean Score During the Double-Blind Treatment Period	For pain interference, the BPI-SF used numerical scales to measure how much pain had interfered with 7 daily activities, including general activity, walking, work, mood, enjoyment of life, relations with others, and sleep in the past 24 hours. The scale used an 11 point Likert scale; range: 0 [does not interfere] to 10 [completely interferes]. BPI pain interference was typically scored as the mean of the 7 interference items. This mean could be used if at least 4 of 7 items had been completed on a given administration.	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, 12 and Endpoint (last visit up to week 12) of the Double-blind treatment period
Secondary	Participants With Adverse Events	An adverse event (AE) was defined in the protocol as any untoward medical occurrence that develops or worsens in severity during the conduct of a clinical study and does not necessarily have a causal relationship to the study drug. Severity was rated by the investigator on a scale of mild, moderate and severe, with severe= an inability to carry out usual activities. Relation of AE to treatment was determined by the investigator. Serious AEs include death, a life-threatening adverse event, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, a congenital anomaly or birth defect, OR an important medical event that jeopardized the patient and required medical intervention to prevent the previously listed serious outcomes.	Day 1 up to Day 52 in Open-Label Titration; Day 1 up to Day 128 in Double-Blind Treatment period
Secondary	Participants With Potentially Clinically Significant Abnormal Vital Signs Values During the Double-Blind Treatment Period	Data represents participants with potentially clinically significant (PCS) vital sign values.; Significance criteria; Pulse - high: >=120 and increase of >= 15 beats/minute from baseline; Pulse - low: <=50 and decrease of >=15 beats/minute; Systolic blood pressure - high: >=180 and increase >=20 mmHg; Systolic blood pressure - low: <=90 and decrease >=20 mmHg; Diastolic blood pressure - high: >=105 and increase of >=15 mmHg; Diastolic blood pressure - low: <=50 and decrease of >=15 mmHg	Day 1 up to Day 128 in Double-Blind Treatment period
Secondary	Participants With Potentially Clinically Significant Abnormal Laboratory Values During the Double-Blind Treatment Period	Data represents participants with potentially clinically significant abnormal serum chemistry, hematology and urinalysis values.; Significance criteria: Blood urea nitrogen: >=10.71 mmol/L; Uric acid: M>=625, F>=506 µmol/L; Hemoglobin: M<=115, F<=95 g/dL; Hematocrit: M<0.37, F<0.32 %; Urinalysis: blood (hemoglobin) and total protein: >=2 unit increase from baseline	Day 1 up to Day 128 in Double-Blind Treatment period
Secondary	Subjective Opiate Withdrawal Scales (SOWS) Scores During the Double-Blind Treatment Period	The results of the SOWS were collected in the e-diary daily during the first 4 weeks of the double blind treatment period and then during clinic visits at weeks 8 and 12 or early termination. The SOWS was a self administered questionnaire used to measure a participant's signs and symptoms of withdrawal from opiates. The scale contained 16 symptoms (eg, my nose is running; I feel restless), the participant rated the intensity on a scale of 0 (not at all) to 4 (extremely) for a total score of 0-64. The daily total score for the first 4 weeks was the largest score observed during the time period preceding that visit. For example, the week 1 score for each participant was the largest total score on any day between baseline and the night before the week 1 visit; the week 4 score for each participant was the largest score observed between the week 2 visit and the night before the week 4 visit.	Weeks 1, 2, 4, 8, 12 and Endpoint (last visit up to Week 12) of the Double-blind treatment period
Secondary	Clinical Opiate Withdrawal Scales (COWS) Scores During the Double-Blind Treatment Period	The COWS was a clinician rated scale used to measure a participant's signs and symptoms of withdrawal from opiates, with ratings based only on apparent relationship to withdrawal. The COWS was performed at day 0 and weeks 1, 2, 4, 8, and 12 (double blind treatment period) or early termination. The scale contained 11 signs/symptoms whose intensity the clinician rated on a scale of 0 to 4 or 5.; A total score was calculated as the sum of the responses to the 11 signs/symptoms for a total range of 0-48. Withdrawal severity was classified, based on the total score, as follows: 0 to 4=normal; 5 to 12=mild; 13 to 24=moderate; 25 to 36=moderately severe; >36=severe	Baseline (end of Open-Label Titration Period), Weeks 1, 2, 4, 8, 12 and Endpoint (last visit up to Week 12) of the Double-blind treatment period
Secondary	Addiction Behavior Checklist (ABC) Total Scores During Both the Open-Label Titration and Double-Blind Treatment Periods	The ABC was a clinician rated scale that consisted of a brief (20 item) questionnaire designed to track behaviors characteristic of addiction related to prescription opioid medications in chronic pain populations. Items were focused on observable behaviors noted both during and between clinic visits. Each affirmative response was counted as one point, and points were added to calculate the total score, consequently resulting in scores ranging from 0 to 20 (0=no addiction-related behaviors seen and higher scores indicating an increasing number of addition-related behaviors seen).; The ABC was to be performed at visits 2 and 7 (beginning and end of Open-label Titration period) and weeks 1, 4, 8, and 12 (Double-blind Treatment period) or early termination.	Baseline for Open-Label Titration period, Baseline for Double-Blind Treatment period (which is also the end of the Open-Label Titration period), Weeks 1, 4, 8, 12, and Endpoint (last visit up to Week 12) of the Double-blind Treatment period
Secondary	Current Opioid Misuse Measures (COMM) Total Scores During Both the Open-Label Titration and Double-Blind Treatment Periods	The COMM was a clinician rated scale developed as a brief self report measure of current aberrant drug-related behavior for patients with chronic pain who were already on long term opioid therapy. A total score was calculated as the sum of the 17 questions. The total score ranged from 0 to 68. A score of 0 indicates no aberrant drug-related behaviors were seen. Patients with a total score of 9 or greater were classified as exhibiting aberrant drug-related behavior.; The COMM was to be performed at visits 2 and 7 (beginning and end of Open-label Titration period) and weeks 1, 4, 8, and 12 (Double-blind Treatment period) or early termination.	Baseline for Open-Label Titration period, Baseline for Double-Blind Treatment period (which is also the end of the Open-Label Titration period), Weeks 1, 4, 8, 12, and Endpoint (last visit up to Week 12) of the Double-blind Treatment period
Secondary	Change From Baseline to Endpoint in the Double-Blind Treatment Phase in Electrocardiogram (ECG) Parameters	A 12-lead ECG was conducted at baseline and the last visit during the double-blind treatment period (week 12, or early termination).	Baseline (end of Open-Label Titration Period), Endpoint (last visit up to Week 12) of the Double-blind treatment period