627 patients with hip osteoarthritis (OA) were randomized to receive either 2.5 mg, 5 mg, or 10 mg doses of intravenous tanezumab (monoclonal antibody against nerve growth factor) or a placebo. The purpose was to compare each treatment's efficacy in lowering pain. After 32 weeks, results indicated that patients who were treated with tanezumab had significantly greater improvements in pain and physical function compared to patients in the placebo group, with 10 mg doses providing the greatest improvements. However, although not statistically significant, the incidence of adverse events was greater in patients of the tanezumab groups in comparison to the placebo group.