Study to Evaluate the Safety and Efficacy of ABT-712 in Subjects With Moderate to Severe Chronic Low Back Pain (CLBP)

A Phase 3, Open-Label Period Followed by a Randomized, Double-blind Placebo-controlled Study of the Analgesic Efficacy of Extended-release Hydrocodone/Acetaminophen (Vicodin CR) Compared to Placebo in Subjects With Chronic Low Back Pain

The primary purpose of the study is to test the efficacy of 2 tablets (twice daily) of ABT-712, compared to placebo, administered over a 4-week period in participants with moderate to severe mechanical chronic low back pain (CLBP).

The study used a randomized withdrawal design with an open label (OL) period prior to a double-blind (DB) period. Participants who were receiving benefit and were tolerating ABT-712 during the OL period were randomized into the DB period. Study drug was given for a total of 8 weeks, which included up to 3 weeks in OL, up to 4 weeks in DB, and a 1-week DB taper. During the OL period, all participants took increasing doses of ABT-712 until they were taking 2 tablets, twice daily. During the DB period, participants in the ABT-712 group took 2 ABT-712 tablets, twice daily throughout the 4 weeks, while participants in the placebo group took 2 placebo tablets twice daily.

Inclusion Criteria:

• Adult male and female subjects who voluntarily sign the informed consent
• Diagnosis of CLBP of 6 months duration

Exclusion Criteria:

• Incapacitated or bedridden subjects
• Subjects with history of surgical or invasive intervention