The objective of this study is to assess the safety and efficacy of the buprenorphine transdermal system (5, 10, and 20 mg) in comparison to placebo transdermal system and hydrocodone/acetaminophen in subjects with chronic back pain. The double-blind treatment intervention duration is 56 days during which time supplemental analgesic medication (ibuprofen) will be provided to all subjects in addition to study drug.

Buprenorphine is a synthetic opioid analgesic with over twenty-five years of international clinical experience indicating it to be safe and effective in a variety of therapeutic situations for the relief of moderate to severe pain. Transdermal systems may offer advantages over currently indicated oral products including ease and convenience of use, improved compliance, possible reduction in patient care, and prolonged and consistent delivery of drug.

Inclusion Criteria:

• clinical evidence of chronic back pain related to intervertebral disc disease, nerve root entrapment, spondylolithesis, osteoarthritis, or other, similar nonmalignant conditions.
• back pain treated with an opioid-containing analgesic at a dose equal to or less than the equivalent of 90 mg of oral morphine per day or 12 or fewer capsules or tablets of an opioid combination analgesic per day.

Exclusion Criteria:

• receiving opioids at an average daily dose of greater than 90 mg of oral morphine equivalents or patients receiving more than 12 tablets per day of short-acting opioid-containing products.
• scheduled to have surgery (including dental) during the study period that involved the use of pre- and/or postoperative analgesics or anesthetics.

Other protocol-specific exclusion/inclusion criteria may apply.