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

Inclusion Criteria:

- Diagnosis of moderate to severe low back pain for ≥6 months

- Treating CLBP with a stable daily maintenance dose of ATC opioid analgesic medication
equivalent to ≥30 mg and ≤160 mg morphine sulfate equivalents (MSE) per day for ≥4
weeks. (Additional as needed [PRN] analgesic rescue medications permitted on top of
the stable daily maintenance dose of ≥30 mg MSE opioid analgesic, but must be
included in the total daily MSE calculation and in combination with the stable daily
maintenance dose not to exceed 160 mg MSE per day)

- Stable health, as determine by Principal Investigator

- Females are practicing abstinence, using a medically acceptable form of
contraception, or 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 within 6 months of screening

- Subjects with 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 of any opioid or acetaminophen

- Surgical procedure for relief of pain within 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