Endocrine Abstracts

Denosumab (DMAB) discontinuation is characterized by an increase in bone turnover and a rapid bone loss. These changes are associated with an increased risk of multiple vertebral fractures (VFx). Prevalent VFx, longer duration of therapy, greater gain in hip BMD during DMAB, and greater loss of hip BMD after DMAB were identified as risk factors for multiple VFx following DMAB cessation in a retrospective analysis of the FREEDOM Extension Study. Case series have indicated that prior bisphosphonate therapy may mitigate the increase in bone turnover after DMAB discontinuation. Current evidence indicates some efficacy of subsequent antiresorptive treatment depending on the duration of DMAB treatment. The ZOLARMAB study investigated if transitioning to zoledronate can prevent the bone loss following DMAB discontinuation. The study included 61 patients with osteopenia, discontinuing DMAB after 4.6 ± 1.6 years. Zoledronate was administrated 6 or 9 months after the last DMAB injection or when bone turnover had increased. BMD decreased significantly in all groups. Incident vertebral fractures were seen in two women in the 9 months group. In conclusion: In case of DMAB discontinuation, alternative antiresorptive treatment should be given and the effect monitored using bone turnover markers or BMD. In patients who have been treated for only a few years, oral bisphosphonates for 1–2 years may prevent the bone loss, however, in patients treated with DMAB for a longer period of time, it is recommended to use zoledronate. In patients at high fracture risk continuing DMAB should be considered given the favourable efficacy and safety profile.