389 patients with moderate-to-severe chronic low back pain (LBP) were randomized to receive one of five dose-ranging subcutaneous injection treatments: 1mg fulranumab every 4 weeks, 3mg fulranumab every 4 weeks, 3mg fulranumab every 4 weeks after a 6mg loading dose, 10mg fulranumab every 4 weeks, or placebo every 4 weeks. The purpose of this study was to determine the efficacy and safety of fulranumab compared to placebo in terms of the LBP numeric rating scale for pain intensity, Oswestry Disability Index scores, Brief Pain Inventory pain intensity and interference scores and treatment relief, and patient global assessment scores. Outcomes were measured until early termination of the study at 12 weeks. Findings indicated no significant differences between all of the fulranumab injection groups compared to the placebo group from baseline to 12 weeks, with the exception of a significantly greater improvement in treatment relief in the 10mg fulranumab group.