Tanezumab Outperforms Placebo, Tramadol in Improving Chronic Back Pain

John Markman, MD

Findings of new research suggest small doses of tanezumab significantly improve worst pain, average pain, and overall pain interference index scores versus placebo in patients with chronic low back pain.

The findings were presented at the European E-Congress of Rheumatology 2020 (EULAR 2020) meeting due to the cancellation of the annual in-person meeting.

John Markman, MD, and investigators from the US, France, and Japan, characterized tanezumab’s effects on pain and function through analysis of Brief Pain Inventory-short form scores. The team evaluated the monoclonal antibody, tanezumab, against nerve growth factor in an 80-week, placebo and tramadol-controlled trial in patients with chronic low back pain and a history of inadequate response to standard-of-care analgesics. Patients either received placebo (n=406), subcutaneous tanezumab 5 mg (every 8 weeks; n=407), subcutaneous tanezumab 10 mg (every 8 weeks; n=407), or oral tramadol prolonged-release (100-300 mg/day; n=605). The mean dose of tramadol was 203 mg per day at week 16.

The primary endpoint of the trial was change in Low Back Pain Intensity at week 16 versus placebo. Additional endpoints included the proportion of patients with >50% improvement in Low Back Pain Intensity at week 16, change in Roland Morris Disability Questionnaire score at week 16, and change in Low Back Pain Intensity at week 2 (all vs placebo). Further, secondary endpoints included Brief Pain Inventory-short form worst pain, average pain, the overall pain interference index, and selected individual domains of the index—general activity, walking ability, sleep, and normal work.

Markman and the team compared least squares mean changes from baseline in Brief Pain Inventory-short form scores between groups at week 16. The scores ranged from 0-10, and higher scores indicated greater pain severity or functional impairment.

For worst pain, the least squares differences from placebo were -.52 for tanezumab 5 mg (P <.01), -.54 for tanezumab 10 mg (P <.01), and -.24 for tramadol (P=.17). For average pain, the mean differences from placebo were -.37 for tanezumab 5 mg (P=.04), -.46 for tanezumab 10 mg (P ≤.01), and -.17 for tramadol (P=.29). From placebo, differences for the pain interference index were -.41 for tanezumab 5 mg (P=.03), -.58 for tanezumab 10 mg (P ≤.01), and -.15 for tramadol (P=.39).

The investigators did not find the effects of tanezumab statistically different from tramadol for worst pain, average pain, and the pain interference index (P >.05). The exception there was for the pain interference index for tanezumab 10 mg (P=.01).

They found tanezumab 10 mg significantly improved individual domains of the pain interference index versus placebo and tramadol (P <.05). What’s more, tanezumab 5 mg significantly improved pain interference with general activity and normal work versus placebo, along with sleep versus placebo and versus tramadol (P <.05).

Overall, 5-10 mg of tanezumab significantly improved pain versus placebo in patients with chronic low back pain.

The study, “Efficacy of Subcutaneous Tanezumab for the Treatment of Chronic Low Back Pain: An Analysis of Brief Pain Inventory-Short Form Scores From A 56-Week, Randomized, Placebo-and Tramadol-Controlled, Phase 3 Trial,” was published online on the EULAR 2020 website.