- Tanezumab, an investigational nerve growth factor inhibitor, is modestly efficacious for moderate-to-severe osteoarthritis (OA) of the hip or knee, but raises joint safety concerns.
Why this matters
- The authors recommend more research on the clinical significance of the efficacy and joint safety findings.
- Multicenter phase 3 randomized controlled trial (n=698) comparing 3 groups with inadequate response to OA analgesics:
- Placebo injections at week 1 and week 8.
- Fixed-dose tanezumab (2.5 mg each).
- Titration tanezumab (2.5 mg and then 5 mg).
- Primary outcomes at week 16 included Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) pain (0-10, no to extreme pain) and WOMAC Physical Function (0-10, no to extreme difficulty).
- Funding: Pfizer Inc.; Eli Lilly and Company.
- The tanezumab groups had higher WOMAC pain scores vs placebo (least-squares mean differences were −0.60; P=.01 for the fixed-dose group and −0.73; P=.002 for the titration group).
- The tanezumab groups had higher WOMAC physical function scores vs placebo (least-squares mean differences were −0.66; P=.007 for the fixed-dose group and −0.89; P<.001 for the titration group>
- Incidence of joint safety events was higher in the tanezumab groups, including total joint replacements (3.5%, 6.9% vs 1.7%, respectively).
- Longer duration of study needed.