This randomized, double-blind, phase 3 study (56-week treatment; 24-week follow-up) assessed
tanezumab in patients with chronic
low back pain and history of inadequate response to standard-of-care
analgesics (NCT02528253). Patients received placebo, subcutaneous
tanezumab (5 or 10 mg every 8 weeks), or oral
tramadol prolonged-release (100-300 mg/day). Primary endpoint was change in
low back pain intensity (LBPI) at week 16 for
tanezumab vs placebo. Key secondary endpoints were proportion of patients with ≥50% decrease in LBPI at week 16, change in Roland Morris Disability Questionnaire at week 16, and change in LBPI at week 2 for
tanezumab vs placebo. Adverse events and joint safety were assessed through weeks 56 and 80, respectively.
Tanezumab 10 mg met the primary endpoint by significantly improving LBPI at week 16 vs placebo; least squares (LS) mean (95% CI) difference = -0.40 (-0.76 to -0.04; P = 0.0281).
Tanezumab 10 mg significantly improved all key secondary endpoints.
Tanezumab 5 mg did not meet the primary endpoint (LS mean [95% CI] treatment difference vs placebo = -0.30 [-0.66 to 0.07; P = 0.1117]), preventing formal testing of key secondary endpoints for this dose. The proportion of patients with ≥50% improvement in LBPI at week 16 was 37.4% in the placebo group, 43.3% in the
tanezumab 5 mg group (Odds ratio [95% CI] vs placebo = 1.28 [0.97 to 1.70; P = 0.0846]), and 46.3% in the
tanezumab 10 mg group (Odds ratio [95% CI] vs placebo = 1.45 [1.09 to 1.91; P = 0.0101]). Prespecified joint safety events were more frequent with
tanezumab 10 mg (2.6%) than
tanezumab 5 mg (1.0%),
tramadol (0.2%), or placebo (0%). Seven patients, all in the
tanezumab 10 mg group (1.4%), underwent
total joint replacement. In conclusion,
tanezumab 10 mg significantly improved
pain and function vs placebo in patients with difficult-to-treat chronic
low back pain.
Tanezumab was associated with a low rate of joint safety events, some requiring
joint replacement.