Incidence of Atypical Femoral Fractures in Patients on Osteoporosis Therapy-A Registry-Based Cohort Study.

Atypical femoral fractures (AFFs) have been reported in patients taking bisphosphonates (BPs) for osteoporosis therapy but also in patients with no exposure to these drugs. In contrast, less is known about the incidence of AFFs in patients taking denosumab. This registry-based cohort study analyzed the incidence of AFFs in patients with suspected or confirmed osteoporosis who were included in the osteoporosis register of the Swiss Society of Rheumatology between January 2015 and September 2019. Statistical analyses included incidence rates, rate ratios, and hazard ratios for AFFs, and considered sequential therapies and drug holidays as time-dependent covariates. Among the 9956 subjects in the cohort, 53 had subtrochanteric or femoral shaft fractures. Ten fractures occurred under BP or denosumab treatment and two under teriparatide therapy. Five fractures were classified as AFFs based on the revised American Society of Bone and Mineral Research case definition of AFFs from 2014. Three AFFs occurred in women being treated with denosumab at the time of diagnosis, all with prior BP use (10, 7, and 1 years, respectively). One AFF developed in a woman receiving ibandronate and one arose in a woman receiving glucocorticoids rather than antiresorptive therapy. The incidence of AFFs per 10,000 observed patient-years was 7.1 in patients receiving denosumab and 0.9 in patients with BP-associated AFFs, yielding a rate ratio of 7.9 (95% confidence interval [CI] 0.63-413), p = 0.073. The risk of AFFs was not significantly higher in patients receiving denosumab therapy compared with BP therapy (hazard ratio = 7.07, 95% CI 0.74-68.01, p = 0.090). We conclude that the risk of AFFs is low in patients taking BPs, denosumab, or both sequentially. All three patients with AFFs under denosumab therapy had undergone prior BP therapy. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Comparison of anti-fracture effectiveness of zoledronate, ibandronate and alendronate versus denosumab in a registry-based cohort study.

UNLABELLED This registry-based study of 3068 patients with osteoporosis compared the anti-fracture effectiveness of denosumab versus bisphosphonates. Denosumab was associated with significantly greater risk reduction than alendronate or ibandronate for vertebral and any fractures. No difference in fracture risk reduction was found between zoledronate and denosumab. PURPOSE To analyse the fracture risk of patients with osteoporosis receiving bisphosphonates or denosumab in a real-world setting. METHODS This registry-based cohort study evaluated patients taking denosumab, bisphosphonates or both sequentially. Fractures were analysed using rates, rate ratios and hazard ratios (HR), including both therapies as time-varying co-variates. Fracture risk hazards were adjusted (aHR) for baseline T-Scores and trabecular bone score (TBS) and were additionally analysed with inverse probability treatment weighting. RESULTS A total of 3068 patients (89% female; median age at treatment onset, 69 years [63 to 76]) received denosumab (median duration 2.8 years, [2.2 to 4.7]), bisphosphonates (3.4 years, [2.1 to 5.7]) or both sequentially. Thus, 11,078 subject-years were assessed for bisphosphonates (41% alendronate, 36% ibandronate, 23% zoledronate) and 4216 for denosumab. Moreover, 48,375 subject-years were observed before treatment onset, in addition to 2593 years of drug holidays. A total of 1481 vertebral fractures (435 under therapy), 1508 non-vertebral fractures (499 under therapy) and 202 hip fractures (67 under therapy) occurred after age 50. The risks of vertebral, non-vertebral and hip fractures were significantly lower under all bisphosphonates, denosumab and drug holidays than before treatment onset (all p < 0.001). After adjusting for age, baseline T-scores and TBS, denosumab was associated with lower risk than alendronate or ibandronate for vertebral fractures (aHR 0.47 (0.35 to 0.64) and 0.70 [0.53 to 0.91], p < 0.001 and p = 0.009, respectively) and any fractures (aHR 0.62 [0.51 to 0.76] and 0.77 [0.64 to 0.92], p < 0.001 and p = 0.004). With propensity weighting, denosumab was associated with a lower hip fracture risk compared to alendronate (HR 0.54 [0.29 to 0.98], p = 0.044). No difference in fracture risk reduction (vertebral, non-vertebral or hip) was found between zoledronate and denosumab. CONCLUSIONS When adjusting for disease severity, denosumab was associated with significantly greater risk reduction than alendronate and ibandronate for vertebral fractures. No difference in fracture risk reduction was found between zoledronate and denosumab

The effect of romosozumab on bone mineral density depending on prior treatment: a prospective, multicentre cohort study in Switzerland.

SUMMARY This multicentre, prospective cohort study measured the effect of romosozumab for 12 months on bone mineral density, taking into account prior therapies. Prior antiresorptive therapy blunted the BMD response to romosozumab, and the duration was correlated with BMD changes at both the lumbar spine and total hip. INTRODUCTION In Switzerland, romosozumab is administered to high-risk osteoporosis patients. Our study aimed to assess the effect of romosozumab on bone mineral density (BMD), taking into account prior therapies. METHODS This multicentre, prospective cohort study measured the effect of romosozumab for 12 months in patients in a nationwide Swiss osteoporosis registry. BMD and bone turnover marker (P1NP and CTX) changes were measured and compared between pre-treated and treatment naïve patients. RESULTS Ninety-nine patients (92 women and 7 men, median age 71 years [65, 76]) were enrolled from January 2021 to December 2023. Among them, 22 had no prior treatment before romosozumab, while 77 had previous therapy (including 23 with a history of prior teriparatide therapy), with a median duration of 6 years [4, 11] of cumulative antiresorptive treatment. Over 12 months, romosozumab led to BMD changes of 10.3% [7.5, 15.5] at the lumbar spine, 3.1% [1.1, 5.8] at the total hip and 3.1% [0.5, 5.3] at the femoral neck, indicating notable variability. Significantly lower BMD responses were observed in pre-treated patients, with the duration of prior antiresorptive therapy inversely associated with BMD increases at the lumbar spine and hip. Other predictors of BMD changes at the total hip included baseline T-scores at the hip, body mass index and baseline CTX level, while the BMD response at the lumbar spine was associated with the lumbar spine T-score at baseline, age and baseline CTX level. CONCLUSION Prior antiresorptive therapy blunted the BMD response to romosozumab, and the duration was correlated with BMD changes at both the lumbar spine and total hip

Clinical Value of Prognostic Instruments to Identify Patients with an Increased Risk for Osteoporotic Fractures: Systematic Review

There is a plethora of evidence available studying the association of risk profiles and the development of osteoporotic fractures. The small number of out-of-sample validations, the large variety of study characteristics, outcomes and follow-up periods impedes from deriving robust summaries and from conclusions regarding the clinical performance of many tools. First and foremost, future activity in this field should aim at reaching a consensus among clinical experts in respect to the existing instruments. Then we call for careful validations and expedient adaptations for local circumstances of the most promising candidates

Effects of zoledronate on bone mineral density and bone turnover after long-term denosumab therapy: Observations in a real-world setting.

BACKGROUND The rebound effect after denosumab discontinuation is lessened with subsequent zoledronate therapy. However, it is unclear whether this mitigation is sufficient after long-term denosumab treatment. OBJECTIVE This retrospective observational study analysed bone mineral density (BMD) and bone turnover marker (BTM) changes after denosumab therapy according to treatment duration and subsequent zoledronate regimen. METHODS We measured the outcomes of 282 women with postmenopausal osteoporosis who discontinued denosumab and received zoledronate 6 months later. In patients with longer denosumab therapy (≥5 years), BTMs were measured every 3 months and a second zoledronate infusion was administered if BTM levels increased by ≥2-fold. The BMD of all women was measured before denosumab therapy, at the last injection and 1 to 2 years after the first zoledronate. RESULTS Bone loss after switching from denosumab to zoledronate was higher in patients with 10 ± 2 denosumab injections (n = 84) compared to 5 ± 2 injections (n = 144, p < 0.001 for lumbar spine and femoral neck), but there was no further increase with treatment durations of ≥15 ± 2 injections (n = 54, p = 0.35 and p = 0.20, respectively). BTMs in patients with ≥10 denosumab injections were elevated 6 months after zoledronate in some patients, but not all. Twenty-four women received a second zoledronate dose 6 months after the first one. BTMs in these patients were subsequently lower, but bone loss at both the lumbar spine and hip was comparable to that in patients with only one zoledronate dose (p = 0.37 for lumbar spine and p = 0.97 for femoral neck). CONCLUSIONS Rebound-associated bone loss reached a plateau after denosumab treatment durations of 4-6 years, irrespective of the frequency of subsequent zoledronate therapy

Fracture prediction in a Swiss cohort.

Fracture prediction is essential in managing patients with osteoporosis, and is an integral component of many fracture prevention guidelines. We aimed to identify the most relevant clinical fracture risk factors in contemporary populations by training and validating short- and long-term fracture risk prediction models in two cohorts. We used traditional and machine learning survival models to predict risks of vertebral, hip and any fractures on the basis of clinical risk factors, T-scores and treatment history among participants in a nationwide Swiss osteoporosis registry (N = 5944 postmenopausal women, median follow-up of 4.1 years between January 2015 and October 2022; a total of 1190 fractures during follow-up). The independent validation cohort comprised 5474 postmenopausal women from the UK Biobank with 290 incident fractures during follow-up. Uno's C-index and the time-dependent area under the receiver operating characteristics curve were calculated to evaluate the performance of different machine learning models (Random survival forests and eXtreme Gradient Boosting). In the independent validation set, the C-index was 0.74 [0.58, 0.86] for vertebral fractures, 0.83 [0.7, 0.94] for hip fractures and 0.63 [0.58, 0.69] for any fractures at year 2, and these values further increased for longer estimations of up to 7 years. In comparison, the 10-year fracture probability calculated with FRAX® Switzerland was 0.60 [0.55, 0.64] for major osteoporotic fractures and 0.62 [0.49, 0.74] for hip fractures. The most important variables identified with Shapley additive explanations (SHAP) values were age, T-scores and prior fractures, while number of falls was an important predictor of hip fractures. Performances of both traditional and machine learning models showed similar C-indices. We conclude that fracture risk can be improved by including the lumbar spine T-score, trabecular bone score, numbers of falls and recent fractures, and treatment information has a significant impact on fracture prediction