In a phase III study of patients with moderate-to-severe osteoarthritis (OA) who had not responded to or could not tolerate standard-of-care analgesics, the nerve growth factor inhibitor tanezumab improved pain, physical function and Patient’s Global Assessment of OA (PGA-OA) at 24 weeks when administered subcutaneously at a dose of 5 mg every 8 weeks (as compared with placebo). Tanezumab 2.5 mg every 8 weeks improved pain and function but not PGA-OA, compared with placebo. Rapidly progressive OA occurred more frequently in the tanezumab 5 mg group than in the tanezumab 2.5 mg group (2.8% vs 1.4%).