Effectiveness and safety of antiresorptive drugs in patients with systemic sclerosis-a retrospective monocentric...

Systemic sclerosis (SSc) is associated with an increased risk of osteoporosis. Gastrointestinal manifestations of SSc such as dysphagia and chronic gastritis affect up to 90% of patients and thus may impair the efficacy and safety of oral antiresorptive treatments. However, data on the comparative effectiveness and safety of antiresorptive therapies in SSc are lacking.

Patients with SSc treated for osteoporosis at our rheumatology department between 2004 and 2024 were included if they had at least 2 dual-energy X-ray absorptiometry measurements 2 years apart (before and during antiresorptive therapy). Primary endpoint was the change in bone mineral density (BMD). Secondary endpoints assessed changes in BMD for individual drugs, with a specific focus on oral compared with parenterally administered drugs. Adverse events were documented descriptively.

A total of 42 patients were included. Overall, antiresorptive therapy significantly improved axial BMD (+3.78%, p = .012), whereas femoral BMD remained unchanged. Subgroup analysis showed a significant axial BMD increase with parenteral therapy (+5.46%, p = .026, n = 21), but not with oral drugs (n = 21). Denosumab yielded the highest axial BMD gain (+7.51%). Overall, no new fractures occurred. One patient developed stage 1 osteonecrosis of the jaw (ONJ) under ibandronate. Three of 19 patients (16%) developed mild gastrointestinal symptoms. No severe gastrointestinal symptoms occurred.

Antiresorptive therapies appear to be effective in patients with SSc. Subgroup analysis suggests that parenteral administration, particularly denosumab, may offer superior efficacy. Gastrointestinal adverse effects were mild and consistent with published rates in the general population, whereas ONJ could be more relevant than in the general population.