Effects of Long-Term Denosumab on Bone Histomorphometry and Mineralization in Women With Postmenopausal Osteoporosis.

Context: Denosumab is a potent antiresorptive agent that reduces fractures in postmenopausal women with osteoporosis. Objective: Determine effects of up to 10 years of denosumab on bone histology, remodeling, and matrix mineralization characteristics. Design and Setting: International, multicenter, randomized, double-blind trial [Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM)] with a long-term open-label extension. Patients: Postmenopausal women with osteoporosis (92 women in FREEDOM, 46 in extension) who provided iliac bone biopsies, including 11 who provided biopsies at multiple time points. Interventions: FREEDOM subjects were randomized 1:1 to subcutaneous denosumab 60 mg or placebo every 6 months for 3 years. Long-term extension subjects continued receiving denosumab, open-label, for 7 additional years. Outcomes: Bone histology, histomorphometry, matrix mineralization. Results: Ten-year denosumab biopsies showed normal histology. Bone histomorphometry indicated normal bone structure and reduced bone remodeling after 10 years of denosumab, similar to levels after 2 and/or 3 and 5 years of denosumab. The degree of mineralization of bone was increased and mineralization heterogeneity was reduced in the denosumab years 2/3 group vs placebo. Changes in these mineralization variables progressed from years 2/3 to year 5 of denosumab, but not thereafter. Conclusions: Denosumab for 2/3, 5, and 10 years was associated with normal histology, low bone remodeling rate, increased matrix mineralization, and lower mineralization heterogeneity compared with placebo. These variables were unchanged from year 5 to year 10. These data, in combination with the maintenance of low fracture rates for up to 10 years as previously reported with denosumab therapy, suggest that strong, prolonged remodeling inhibition does not impair bone strength.

Dynamics of cinacalcet use and biochemical control in hemodialysis patients: a retrospective New-user cohort design.

BACKGROUND: Cinacalcet is used to treat secondary hyperparathyroidism among hemodialysis patients. Large-scale epidemiologic studies describing patterns of cinacalcet use, effects on parathyroid hormone (PTH), calcium, and phosphorous levels, and predictors of discontinuation have not been previously reported. METHODS: This retrospective cohort study used a clinical database of a large U.S. dialysis provider (2007-2010) merged with administrative data from the United States Renal Data System. Among new users of cinacalcet with Medicare coverage, trends in PTH, calcium, and phosphorus were measured in 30-day intervals following cinacalcet initiation. RESULTS: Seventeen thousand seven hundred sixty-three eligible initiators contributed 111,047 30-day follow-up intervals. Of these, 56 % discontinued cinacalcet by month 4. Of those discontinuing, 76.3 % reinitiated. Mean values of PTH, calcium, and phosphorus decreased to recommended levels within 4 months following initiation. Proximal PTH levels < 150 pg/mL were associated with discontinuation: HR = 1.23 (95 % CI: 1.12, 1.36), whereas low calcium (< 7.5 mg/dL) was suggestive of an association, HR = 1.09 (95 % CI 0.91, 1.32). Being in the Part D gap period increased discontinuation risk: HR = 1.09 (95 % CI: 1.03, 1.16). Low-income subsidy status decreased discontinuation risk: HR = 0.77 (95 % CI 0.69, 0.86). Predictors of reinitiation included low-income subsidy, HR = 1.32 (95 % CI 1.22, 1.43); higher albumin level, HR = 1.23 (95 % CI 1.10, 1.36) and higher calcium level, HR = 1.26 (95 % CI 1.19, 1.33). CONCLUSIONS: Substantial and expected declines in laboratory values occurred following cinacalcet initiation. Early discontinuation and reinitiation of cinacalcet were common and may have occurred for clinical and economic reasons.

Anemia management practice patterns in small dialysis organizations following implementation of the prospective payment system.

BACKGROUND: The impact of the United States Prospective Payment System (PPS) "bundle payment system" on anemia management within small dialysis organizations (SDOs) was studied to evaluate the financia burden on SDOs. METHODS: Facilities enrolled in the original study on SDOs were grouped into three hemoglobin (Hb) categories by subject-months: > 25% of subjectmonths with Hb < 10 g/dL (sub-10); > 25% of subject-months with Hb > 12 g/dL (super-12); remaining facilities (10 - 12 group). Subjectlevel data aggregated to facility level for Hb concentration, intravenous (IV) epoetin ± (EA) dose per administration, dose titration, and EA administration frequency during the baseline and follow-up periods were described. RESULTS: Baseline demographic characteristics were imbalanced between the sub-10 (n = 7) and super-12 facilities (n = 5). Mean (SD) Hb concentrations were similar for sub-10 (11.1 (3.0) g/dL) and super-12 (11.6 (2.2) g/dL) facilities during the baseline period, but differed during the follow-up period (10.4 (2.7) vs. 11.4 (2.3) g/dL). The median (Q1, Q3) EA IV dose per administration during follow-up was 3,726 (3,467, 3,961) and 5,712 (4,816, 7,324) units in the sub-10 and super-12 facilities, respectively. A small trend toward upward titration was seen. CONCLUSIONS: Results suggest a difference in anemia management between sub-10 and super-12 facilities during the first year of PPS implementation. Future analyses evaluating patterns of reimbursement and shifts in clinical practice guidelines are warranted globally.