Based on lack of efficacy in PAI2003, sponsor made the decision to discontinue the trial.

The purpose of this study is to compare the safety and effectiveness of different doses of JNJ-42160443 with placebo in the treatment of chronic, moderate to severe low back pain patients with a diagnosis of chronic low back pain.

This is a randomized (study drug assigned by chance), double-blind (neither the physician nor the patient knows the name of the assigned drug) study to evaluate the safety and effectiveness of different doses of JNJ-42160443 compared with placebo in the treatment of patients with a diagnosis of chronic low back pain who have moderate to severe, chronic low back pain that is not controlled by standard pain medications. JNJ-42160443 (10 mg/ml) or matching placebo given as a subcutaneous (SC) (under the skin) injection (inj) once every 4 weeks (wks); one of four JNJ-42160443 doses (1 mg every 4 wks; 3 mg every 4 wks; 6 mg loading dose on Day 1 followed by 3 mg every 4 wks; or 10 mg every 4 wks, or matching placebo for up to 104 wks (12-wk double-blind efficacy period + 92-wk double-blind extension period).

Inclusion Criteria:

• Diagnosis of chronic low back pain

Exclusion Criteria:

• Pain with radiation to the extremity and with neurologic signs
• history within the past year of any of the following: seizure disorder
• intrathecal therapy and ventricular shunts, mild or moderate traumatic brain injury, stroke, or transient ischemic attack, meningitis
• History of brain injury within the past 15 years consisting of >= 1 of the following, or with residual sequalae suggesting transient changes in consciousness: brain contusion, intracranial hematoma, either unconsciousness or posttraumatic amnesia lasting more than 24 hours
• History of epilepsy or multiple sclerosis
• Current diagnosis of fibromyalgia, complex regional pain syndrome (including reflex sympathetic dystrophy or causalgia), acute spinal cord compression, bowel or bladder dysfunction as a result of cauda equine compression, back pain caused by secondary infection, or pain caused by confirmed or suspected neoplasm
• Any new or unresolved neurologic deficits, including progressive deficits, within 6 months before screening