The objective of this study is to demonstrate the effectiveness and tolerability of the buprenorphine transdermal system (5, 10, and 20 mg) in comparison to placebo transdermal system and immediate release oxycodone/acetaminophen in subjects with chronic low back pain inadequately treated with non-opioid analgesics. The double-blind treatment intervention duration is 60 days.

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:

• unacceptable pain control despite currently taking a nonsteroidal anti-inflammatory drug considered at a therapeutic and/or tolerated dose or currently taking </=2 short-acting opioid doses per day.
• taking >/=3 opioid doses per day with or without acceptable pain control.

Exclusion Criteria:

• receiving opioids at an average daily dose of greater than 60 mg of oral morphine equivalents or subjects receiving more than 6 tablets per day of a short-acting opioid.
• scheduled to have surgery (including dental) involving the use of post- or preoperative analgesics or anesthetics during the study period.

Other protocol-specific exclusion/inclusion criteria may apply.