Long-term effectiveness of zoledronic acid in patients with Paget's disease of bone - a retrospective cohort study.

purposeThe aims of the current study were to describe clinical and biochemical features of patients with Paget disease of bone (PDB) followed at our medical center, and to examine the long-term effectiveness of zoledronate.

methodsRetrospective cohort study included consecutive patients≥18 years with a diagnosis of PDB, followed in the Rabin Medical Center (RMC) Institute of Endocrinology from 1973 to 2023. The cohort comprised two groups: patients treated/not treated with zoledronic acid (ZOL/NZOL). The primary outcome was the percentage of patients who achieved a biochemical therapeutic response.

resultsOverall, 101 patients with PDB were included, 68 in the ZOL group and 33 in the NZOL group. The mean age was 65.2 ± 10.0 years, and 47% were female. Notably, 77% exhibited monostotic involvement, and only 3% had experienced fractures attributed to PDB. Mean ALP level at diagnosis was 160 ± 70.6 U/L. The median follow-up duration was 17 years since PDB diagnosis, comparable between the groups. Primary outcome was more prevalent in the ZOL compared to the NZOL group [42 patients (88%) VS 11 patients (52%) respectively, P = 0.004]. At the end of follow-up, mean ALP levels in the NZOL group were significantly higher than the levels in the ZOL group irrespective of the number of infusions received.

conclusionThe majority of patients with PDB experience a mild disease course, marked by monostotic involvement and a low prevalence of fractures. Zoledronic acid effectively manages PDB, providing sustained biochemical response. The necessity for multiple zoledronic acid injections remains questionable, often implemented due to osteoporosis.