Why this study matters

This was the longest study to focus on the efficacy and safety of analgesics (not only tanezumab, but also NSAIDs) among OA patients to date. 

Because NSAIDs should not be used to treat OA long-term, tanezumab, a monoclonal antibody that blocks the associated pain pathway and can be safely administered long-term, is a promising treatment option that should be considered in patients who have failed NSAID treatment and/or may require long-term treatment.

Study design

This phase 3 RCT was conducted at 446 sites in the USA, Europe, Latin America, and Oceania. Patients with moderate-to-severe OA were enrolled in a 56-week double-blind (oral NSAID + subcutaneous tanezumab [2.5 or 5 mg] or placebo) treatment period, followed by a 24-week safety follow-up period. 

The 1312 study patients who completed the treatment phase and 1222 who completed the safety follow-up evaluations had Kellgren-Lawrence grade > 2 hip or joint OA and inadequate pain relief with standard analgesics. The efficacy endpoints were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Patient Global Assessment of Osteoarthritis (PGA-OA).

Results and conclusion

The majority of patients with moderate-to-severe OA who were treated with NSAIDs or tanezumab reported improvement in pain symptoms as early as week 2 of treatment that was sustained through week 56 of treatment.  The pain relief with tanezumab was equivalent or greater than the pain relief achieved with NSAIDs. 

The incidence of adverse events and treatment discontinuation due to adverse events were similar between the patients treated with NSAIDs and the 2.5 mg dose of tanezumab.