The Time Course Changes in Bone Metabolic Markers after Administering the Anti-Receptor Activator of Nuclear Factor-Kappa B Ligand Antibody and Drug Compliance among Patients with Osteoporosis.

Abstract

Retrospective study. We conducted a study to investigate the time course changes in bone metabolic markers after the administration of the anti-receptor activator of nuclear factor-kappa B ligand (RANKL) antibody and to assess drug compliance among osteoporotic patients. The anti-RANKL antibody is expected to provide an improvement in those with a bone metabolism disorder. However there are only a few clinical reports available on the effect of treatment. We included 40 post-menopausal osteoporotic patients who received the anti-RANKL antibody. To determine the time course changes in the bone metabolic markers, we measured the serum tartrate-resistant acid phosphatase 5b (TRACP 5b; a bone resorption marker) and the serum N-terminal propeptide of type 1 collagen (P1NP; a bone formation marker) levels prior to and 1 month after administrating the anti-RANKL antibody. To evaluable drug compliance, we assessed the dropout rate during treatment and at 6 months after treatment. The average TRACP 5b level significantly decreased from 574.8 mU/dL before treatment to 153.2 mU/dL 1 month after treatment (p<0.05). There was no significant difference in the average P1NP level, which was 56.9 µG/L and 35.1 µG/L before and 1 month after treatment, respectively (p>0.05). As for drug compliance, we did not have any dropouts during the treatment or after 6 months (dropout rate: 0%). Our study suggests that anti-RANKL antibody treatment suppresses bone resorption and maintains bone formation.