Effects of romosozumab with and without active vitamin D analog supplementation for postmenopausal osteoporosis.

Background & Aims: Although romosozumab is attracting attentions as one of favorably used drugs in today's osteoporosis treatment, there has been no report discussing the differences in the efficacy of romosozumab in the presence or absence of combined use of active vitamin D analog yet. This prospective cohort investigation compared the effects of 12-month romosozumab treatment to increase bone mineral density (BMD) for postmenopausal osteoporosis to observe the influence of combined vitamin D supplementation.

Methods: During 12-month romosozumab treatment, 175 patients were divided into the VD group (with vitamin D analog: N = 88) and the NVD group (without vitamin D analog: N = 87), and the change in BMD from baseline was measured at 6 and 12 months as well as alterations in bone turnover markers, serum calcium, and the incidence of adverse events during the administration period.

Results: The average 12-month percentage change from baseline level for lumbar spine BMD was comparable at 12.3% in the VD group and 12.1% in the NVD group. The changes in BMD at the total hip and femoral neck showed no significant differences between the groups. The VD group exhibited a significantly smaller increase in procollagen type 1 N-terminal propeptide 1 (P1NP) and larger decrease in tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) versus the NVD group. The reduction rate of serum-corrected calcium was significantly less in the VD group than in the NVD group. Adverse events were minor in both groups, with no significant difference in the frequency of new fractures.

Conclusion: Romosozumab may significantly increase BMD regardless of the addition of an active vitamin D analog.