The purpose of this study is to evaluate the analgesic efficacy of Oxycodone DETERx compared with placebo in opioid-experienced and opioid-naive subjects with moderate-to-severe chronic low back pain requiring around-the-clock opioid analgesia for an extended period of time.

Inclusion Criteria:

• Male or non-pregnant female 18-75 years of age (inclusive) at the time of consent.
• Must have a clinical diagnosis of moderate-to-severe CLBP for a minimum of 6 months prior to screening.
• Must qualify for ATC opioid therapy for treatment of CLBP.
• Must be classified as non-malignant and non-neuropathic (Class 1 and 2), neuropathic (Class 3), or symptomatic for more than 6 months after low back pain surgery (Class 9) based on the Quebec Task Force Scale score.
• Female subjects of childbearing potential will use an acceptable method of birth control.
• Must be in general good health based on screening physical examination.
• Must be willing and able to comply with all study procedures and visit requirements.

Exclusion Criteria:

• Known to be refractory or intolerant to the analgesic effects of opioids or have failed previous opioid therapy.
• A medical condition that would compromise the subject's ability to swallow, absorb, metabolize, or excrete the study drug, including (but not limited to) intractable nausea and/or vomiting and/or severe gastrointestinal narrowing (pathologic or iatrogenic), bowel obstruction, ileostomy, colostomy, or is suspected of having paralytic ileus.
• A surgical procedure for back pain within 6 months prior to the Screening Visit.
• Any other chronic pain condition other than CLBP that would interfere with the assessment of CLBP (e.g., osteoarthritis, rheumatoid arthritis, post-herpetic neuralgia, pain associated with diabetic neuropathy, fibromyalgia, migraine headaches requiring opioid therapy).
• Known history of major depressive disorder that is not controlled with medication or has other conditions that produce significant cognitive or emotional disability.
• Any clinically significant unstable medical abnormality or acute or chronic disease of the cardiovascular, gastrointestinal, respiratory (e.g., chronic obstructive pulmonary disease), hepatic, or renal systems.
• Known history of alcohol and/or drug abuse.
• Positive urine drug screen for illegal or non-prescribed drugs
• Known history of seizure disorder, epilepsy, convulsions, or increased intracranial pressure anytime during the subject's life except pediatric febrile seizures.
• Known history of head injury within 6 months of Screening Visit.
• Current malignancy or a history within past 2 years of malignancy, with the exception of basal cell carcinoma or cervical carcinoma in situ that have been successfully treated.
• Positive for human immunodeficiency virus (HIV) or hepatitis B surface antigen, or hepatitis C antibody
• Subject is not able or is unwilling to meet the study attendance requirements.

Other protocol specific inclusion and exclusion criteria may apply.