Intravenous neridronate in the treatment of acute painful knee osteoarthritis: a randomized controlled study.

Abstract

The aim of this randomized, double-blind, placebo-controlled study was to assess the efficacy of i.v. neridronate in controlling pain in patients with acute painful knee OA. Sixty-four patients with acute knee pain (<3 months duration) suffering from knee OA with an MRI showing bone marrow lesions (BMLs) were randomized to receive either neridronate 100 mg given four times over 10 days or placebo. After 50 days the patients underwent clinical assessment and a further MRI was performed. Primary outcome was pain changes measured by a visual analogue scale (VAS; range 0-100). Secondary endpoints were WOMAC pain score, McGill pain questionnaire and 36-Item Short Form Health Survey. BMLs were evaluated by whole-organ MRI score. At the day of the last infusion the VAS decreased significantly more in the neridronate group [from 59.0 (s.d. 14.7) to 30.4 (s.d. 15.6); -48.4%; P < 0.001]. Fifty days later the VAS remained unchanged in the placebo group, while a further significant decrease was observed in the neridronate group [from 30.4 (s.d. 15.6) to 9.4 (s.d. 10.8); -69.1%; P < 0.001]. Significant improvements compared with the placebo group were found for most of the other indices of pain and quality of life. The BMLs score in the neridronate group showed significant decreases compared with basal values and those of the placebo-treated patients. Four months after the treatment, 72% of the placebo-treated patients resumed analgesic or anti-inflammatory drugs, but only 12.9% resumed treatment in the neridronate group. In patients with acute painful knee OA, four infusions of neridronate are associated with a clinically relevant pain benefit. ClinicalTrials.gov (http://clinicaltrials.gov), NCT01803360.