Efficacy Study to Evaluate Buprenorphine HCl Buccal Film in Opioid-Naive Subjects

Inclusion Criteria: * Diagnosis of moderate to severe low back pain for ≥6 months * Treating CLBP with a stable daily maintenance dose of non-opioid analgesic medication up to 10 mg morphine sulfate equivalents (MSE) per day for ≥4 weeks. (Additional as needed \[PRN\] non-opioid analgesic medications permitted on top of the stable daily maintenance dose of non-opioid analgesic) * Stable health, as determined by Principal Investigator * Are female who are practicing abstinence or using a medically acceptable form of contraception or have been post-menopausal, biologically sterile, or surgically sterile for more than 1 year * Willing and able to comply with all protocol required visits and assessments Exclusion Criteria: * Current cancer related pain or received chemotherapy with 6 months of screening * Receiving opioid analgesic medication \>10 mg MSE per day within 28 days of screening * Subjects with a history of other chronic painful conditions * Reflex sympathetic dystrophy or causalgia, acute spinal cord compression, cauda equina compression, acute nerve root compression, meningitis, or discitis * Allergy or contraindications to any opioid or acetaminophen * Surgical procedure for relief of pain with 6 months * Hypokalemia or clinically unstable cardiac disease, including: unstable atrial fibrillation, symptomatic bradycardia, unstable congestive heart failure, or active myocardial ischemia * QT interval corrected using Fridericia's formula (QTcF) of ≥450 milliseconds on the 12-lead electrocardiogram (ECG) * History of long QT syndrome or a family member with this condition * Moderate to severe hepatic impairment * Moderate to severe renal impairment * Current or past history of alcohol abuse * Positive urine toxicology screen for drug of abuse * History or abnormalities on physical exam, vital signs, electrocardiogram, or laboratory values