Denosumab efficacy in GIOP not modified by prior antiosteoporotic therapy
Denosumab yields increases in bone mineral density (BMD) in patients with glucocorticoid-induced osteoporosis (GIOP), and this benefit is not influenced by prior antiosteoporotic treatment, as shown in a study.
The study used real-world data and included 66 GIOP patients initiating denosumab, all of whom had been receiving several dosages of prednisolone (2–20 mg) for rheumatoid arthritis and connective tissue diseases. Prior to denosumab initiation, 23 patients had been treated with daily teriparatide and 27 with bisphosphonates. The remaining 16 were treatment naïve.
Mean BMD at the lumbar spine increased from baseline by 2.85 percent at 6 months (p<0.0001) and by 4.40 percent at 12 months (p<0.0001). More than half (68.2 percent) of the population exhibited gains >3 percent, whereas only few (16.67 percent) showed decline at 12 months. Furthermore, all bone turnover markers (NTX, BAP and P1NP) decreased at 6 months. [EULAR 2018, abstract THU0494]
Among patients with prior exposure to antiosteoporotic agents, transition to denosumab from bisphosphonates vs from teriparatide yielded a greater increase in BMD at 12 months (4.71 percent vs 3.71 percent). However, the difference in BMD changes between these two groups was not significant, not even when compared against that seen in the group of patients who did no transition or were treatment naïve.
Dosage or duration of prednisolone, body weight, and gender were significantly associated with a BMD increase of >3 percent at 12 months in a univariate logistic regression model. On further analysis, only prednisolone dose showed an independent association with clinical response to denosumab (odds ratio, 1.36; 95 percent CI, 1.045–1.761; p<0.01).
There were no reports of hypocalcaemia and osteonecrosis of the jaw ever occurring during the study period.
“Despite the good clinical efficacy of denosumab for primary osteoporosis, the 2017 American College of Rheumatology guideline for GIOP placed denosumab as second-line treatment because of lack of clinical experience with concomitant use of immunosuppressive agents,” the authors said.
The present data demonstrate that denosumab produces BMD gains in GIOP regardless of prior antiosteoporotic treatment, they added. In line with this, clinicians should consider denosumab in the treatment for GIOP, especially for patients exposed to higher glucocorticoid doses or at the time when the efficacy of bisphosphonates is diminished.