Impact of romosozumab treatment for 24 months after switching from denosumab: three case reports

TL;DR

This study examines bone density changes in three osteoporosis patients who switched from denosumab to romosozumab for 24 months.

Contribution

The study is the first to report on 24-month romosozumab treatment outcomes in patients previously treated with denosumab.

Findings

Bone mineral density (BMD) showed variable improvements after 24 months of romosozumab in patients previously treated with denosumab.

Bone turnover markers like P1NP and CTX peaked early and then declined in some patients but increased in others.

Results suggest that romosozumab may have mixed effects on BMD and bone turnover in patients with prior denosumab exposure.

Abstract

Prior denosumab use in osteoporosis patients diminishes the BMD gains from a subsequent 12-mo romosozumab regimen. However, few studies have explored BMD gains after 24 mo of romosozumab therapy. BMD at the LS-BMD, FN-BMD, and TH-BMD and P1NP and C-terminal telopeptide of type I collagen (CTX) levels were measured after 24 mo of romosozumab therapy in 3 osteoporosis cases with prior denosumab use. The changes in cases 1-3 at 12 and 24 mo, respectively, were as follows: LS-BMD (−2.9% and 7.4%, 0.9% and 7.9%, 7.2% and 7.9%), FN-BMD (3.2% and 7.1%, −1.2% and 2.0%, 2.7% and 2.1%), and TH-BMD (−1.2% and 6.7%, −4.9% and −0.3%, −0.3% and 3.2%). The P1NP and CTX levels in case 1 (18.80 ng/mL, 0.042 ng/mL) peaked at 6 mo (185.00 ng/mL, 1.280 ng/mL) and then decreased at 24 mo by 60.8% and 65.3%, respectively. The P1NP and CTX levels in case 2 (17.10 ng/mL, 0.059 ng/mL) peaked at 12 mo (132.00 ng/mL, 1.190 ng/mL) and then decreased at 24 mo by 65.3% and 24.3%, respectively. In case 3, the P1NP and CTX levels (56.10 ng/mL, 0.490 ng/mL) increased at 24 mo by 233.3% and 375.5%, respectively. This is the first report of a 24-mo romosozumab regimen in a small group of osteoporosis patients with prior denosumab use having varied effects on BMD and bone turnover. Nonetheless, larger controlled studies are needed to confirm these findings.

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