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1.
J Bone Miner Res ; 34(9): 1597-1608, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31233639

RESUMO

Sclerostin, a protein produced by osteocytes, inhibits bone formation. Administration of sclerostin antibody results in increased bone formation in multiple animal models. Romosozumab, a humanized sclerostin antibody, has a dual effect on bone, transiently increasing serum biochemical markers of bone formation and decreasing serum markers of bone resorption, leading to increased BMD and reduction in fracture risk in humans. We aimed to evaluate the effects of romosozumab on bone tissue. In a subset of 107 postmenopausal women with osteoporosis in the multicenter, international, randomized, double-blind, placebo-controlled Fracture Study in Postmenopausal Women with Osteoporosis (FRAME), transiliac bone biopsies were performed either after 2 (n = 34) or 12 (n = 73) months of treatment with 210 mg once monthly of romosozumab or placebo to evaluate histomorphometry and microcomputed tomography-based microarchitectural endpoints. After 2 months, compared with either baseline values assessed after a quadruple fluorochrome labeling or placebo, significant increases (P < 0.05 to P < 0.001) in dynamic parameters of formation (median MS/BS: romosozumab 1.51% and 5.64%; placebo 1.60% and 2.31% at baseline and month 2, respectively) were associated with a significant decrease compared with placebo in parameters of resorption in cancellous (median ES/BS: placebo 3.4%, romosozumab 1.8%; P = 0.022) and endocortical (median ES/BS: placebo 6.3%, romosozumab 1.6%; P = 0.003) bone. At 12 months, cancellous bone formation was significantly lower (P < 0.05 to P < 0.001) in romosozumab versus placebo and the lower values for resorption endpoints seen at month 2 persisted (P < 0.001), signaling a decrease in bone turnover (P = 0.006). No significant change was observed in periosteal and endocortical bone. This resulted in an increase in bone mass and trabecular thickness with improved trabecular connectivity, without significant modification of cortical porosity at month 12. In conclusion, romosozumab produced an early and transient increase in bone formation, but a persistent decrease in bone resorption. Antiresorptive action eventually resulted in decreased bone turnover. This effect resulted in significant increases in bone mass and improved microarchitecture. © 2019 American Society for Bone and Mineral Research.

2.
Proc Natl Acad Sci U S A ; 116(24): 11747-11753, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31127046

RESUMO

The replisome is a multiprotein machine that is responsible for replicating DNA. During active DNA synthesis, the replisome tightly associates with DNA. In contrast, after DNA damage, the replisome may disassemble, exposing DNA to breaks and threatening cell survival. Using live cell imaging, we studied the effect of UV light on the replisome of Escherichia coli Surprisingly, our results showed an increase in Pol III holoenzyme (Pol III HE) foci post-UV that do not colocalize with the DnaB helicase. Formation of these foci is independent of active replication forks and dependent on the presence of the χ subunit of the clamp loader, suggesting recruitment of Pol III HE at sites of DNA repair. Our results also showed a decrease of DnaB helicase foci per cell after UV, consistent with the disassembly of a fraction of the replisomes. By labeling newly synthesized DNA, we demonstrated that a drop in the rate of synthesis is not explained by replisome disassembly alone. Instead, we show that most replisomes continue synthesizing DNA at a slower rate after UV. We propose that the slowdown in replisome activity is a strategy to prevent clashes with engaged DNA repair proteins and preserve the integrity of the replication fork.

3.
J Clin Endocrinol Metab ; 104(8): 3450-3461, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31125092

RESUMO

CONTEXT: Evidence for further nonvertebral fracture (NVF) reductions with long-term antiresorptive therapy in osteoporosis is lacking. OBJECTIVE: To evaluate NVF risk reduction in subjects receiving ≤10 years of denosumab treatment. DESIGN: Phase 3, randomized, placebo-controlled, 3-year Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial (NCT00089791) and its open-label 7-year extension (NCT00523341). SETTING: One hundred seventy-two study centers worldwide. PATIENTS: Women 60 to 90 years, lumbar spine or total hip bone mineral density T-scores <-2.5 (≥-4.0 at both). INTERVENTIONS: Subjects randomly assigned 1:1 denosumab 60 mg SC Q6M (long-term) or placebo (crossover) in FREEDOM; eligible subjects could enroll in the extension to receive denosumab 60 mg SC Q6M. MAIN OUTCOME MEASURES: NVF Exposure-adjusted subject incidence (per 100 subject-years) during denosumab treatment years 1 to 3 and 4 to 7 (all subjects) and years 4 to 10 (long-term only), and rate ratios (RRs) for years 4 to 7 or 4 to 10 vs 1 to 3. RESULTS: Among 4074 subjects (2343 long-term, 1731 crossover), NVF rates (95% CI) in all subjects were 2.15 (1.90 to 2.43) during years 1 to 3 and 1.53 (1.34 to 1.75) during years 4 to 7 of denosumab treatment [RR (95% CI) = 0.72 (0.61 to 0.86); P < 0.001]; in long-term only were 1.98 (1.67 to 2.34) during years 1 to 3 and 1.44 (1.24 to 1.66) during years 4 to 10 [RR = 0.74 (0.60 to 0.93); P = 0.008]. combined osteonecrosis of the jaw and atypical femoral fracture rate was 0.06. CONCLUSIONS: Long-term denosumab treatment, >3 and ≤10 years, was associated with further reductions in NVF rates compared with the first 3 years.

4.
J Bone Miner Res ; 34(4): 626-631, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30601581

RESUMO

Denosumab, a RANKL inhibitor, reduced the risk of vertebral, hip, and nonvertebral fractures in the Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months (FREEDOM) trial of postmenopausal women with osteoporosis compared with placebo. Previous bone histomorphometric analysis in FREEDOM showed decreased bone resorption and turnover in cancellous bone after 2 and 3 years. The purpose of the present study was to evaluate the effects of denosumab compared with placebo in the cortical compartment from transiliac bone biopsies obtained during FREEDOM. A total of 112 specimens were evaluable for cortical histomorphometry, including 67 obtained at month 24 (37 placebo, 30 denosumab) and 45 at month 36 (25 placebo, 20 denosumab). Eroded surface, osteoclast surface, erosion depth, and wall thickness were measured on the endocortical surface. Cortical thickness and cortical porosity were also measured. Dynamic parameters of bone formation were assessed for endocortical, periosteal, and intracortical envelopes. Endocortical osteoclast surface, eroded surface, and mean and maximum erosion depth were significantly lower in the denosumab group versus placebo at months 24 and 36 (p < 0.0001 to p = 0.04). Endocortical wall thickness and intracortical measures (cortical porosity and cortical thickness) were not different between the two groups. Dynamic parameters were low with tetracycline labels in cortical bone observed in 13 (43%) and 10 (50%) of denosumab biopsies at months 24 and 36, respectively, reflecting a marked decrease in bone turnover. In conclusion, our data reveal the mechanism of action of denosumab on cortical bone: inhibition of osteoclastic resorption and reduced activation of new remodeling sites. In addition, reduced endocortical erosion depth with no change of wall thickness may contribute to increased bone strength by reducing the bone loss and fragility associated with deep resorption cavities and may likely contribute to the greater BMD gain with denosumab than with other antiresorptive agents. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

5.
Lancet Diabetes Endocrinol ; 6(6): 445-454, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29631782

RESUMO

BACKGROUND: Glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis and is associated with an estimated annual fracture rate of 5%. We aimed to assess the efficacy and safety of denosumab compared with risedronate in glucocorticoid-induced osteoporosis. METHODS: We did a 24-month, double-blind, active-controlled, double-dummy, non-inferiority study at 79 centres in Europe, Latin America, Asia, and North America. Eligible patients were aged 18 years or older and were receiving glucocorticoids (≥7·5 mg prednisone daily, or equivalent) for at least 3 months (glucocorticoid continuing) or less than 3 months (glucocorticoid initiating) before screening. Patients younger than 50 years needed to have a history of osteoporosis-related fracture; glucocorticoid-continuing patients aged 50 years or older needed a lumbar spine, total hip, or femoral neck bone mineral density T score of -2·0 or less, or -1·0 or less if they had a history of osteoporosis-related fracture. Participants were randomly assigned (1:1) to either 60 mg subcutaneous denosumab every 6 months and oral placebo daily for 24 months, or 5 mg oral risedronate daily and subcutaneous placebo every 6 months for 24 months. Randomisation was stratified by sex within each subpopulation, and was done with an interactive voice-response system. Active drugs and corresponding placebos had identical packaging, labels, and appearance. The primary outcome was non-inferiority of denosumab to risedronate in terms of percentage change from baseline in lumbar spine bone mineral density at 12 months based on non-inferiority margins (-0·7 and -1·1 percentage points for the glucocorticoid-continuing and glucocorticoid-initiating subpopulations, respectively). Superiority was also assessed as a secondary outcome. The primary efficacy set included all randomly assigned participants who had a baseline and postbaseline lumbar spine bone mineral density measurement, and was analysed according to randomised treatment assignment. The safety analysis set included all randomly assigned participants who received at least one dose of investigational product, and was analysed by actual treatment received. This study is registered with ClinicalTrials.gov (NCT01575873) and is completed. FINDINGS: Between March 28, 2012, and June 30, 2015, 795 patients, 505 of whom were glucocorticoid continuing and 290 of whom were glucocorticoid initiating, were enrolled and randomly assigned (398 to denosumab, 397 to risedronate). Denosumab was both non-inferior and superior to risedronate at 12 months for effect on bone mineral density at the lumbar spine in both glucocorticoid-continuing (4·4% [95% CI 3·8-5·0] vs 2·3% [1·7-2·9]; p<0·0001) and glucocorticoid-initiating (3·8% [3·1-4·5] vs 0·8% [0·2-1·5]; p<0·0001) subpopulations. Incidence of adverse events, serious adverse events (including infections), and fractures was similar between treatment groups. The most common adverse events were back pain (17 [4%] patients in the risedronate group and 18 [5%] in the denosumab group) and arthralgia (21 [5%] patients in the risedronate group and 17 [4%] in the denosumab group). Serious infection occurred in 15 (4%) patients in the risedronate group and 17 (4%) patients in the denosumab group. INTERPRETATION: Denosumab could be a useful treatment option for patients newly initiating or continuing glucocorticoids who are at risk of fractures. FUNDING: Amgen.

6.
J Pharm Biomed Anal ; 154: 454-459, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29587225

RESUMO

Recombinant human erythropoietin (EPO) is a therapeutic glycoprotein widely used for treating anemia. EPO glycans carry extensive sialylation and the level of the modification is known to affect receptor binding, protein stability and pharmacokinetics. Nonetheless, a detailed understanding of the effects of sialylation on EPO conformation and dynamics is still lacking. Here we investigate the changes to EPO dynamics following enzymatic trimming of terminal sialic acid by amide hydrogen deuterium exchange mass spectrometry (HDX-MS). The results revealed that desialylation enhances structural flexibility near the glycosylation sites, with greater effects observed around the O-glycosylation site relative to the N-glycosylation sites. The affected regions are surface-exposed loops connecting the helix bundle, which do not appear to reduce the thermostability of the molecule as revealed from melting measurement. Our findings demonstrate the feasibility of HDX-MS technique in deciphering the function of specific type of glycosylation that can provide novel insights into the role of sialylation on protein therapeutics.


Assuntos
Deutério/química , Eritropoetina/química , Hidrogênio/química , Proteínas Recombinantes/química , Sequência de Aminoácidos , Medição da Troca de Deutério/métodos , Glicosilação , Humanos , Espectrometria de Massas/métodos , Ácido N-Acetilneuramínico/química , Polissacarídeos/química , Ligação Proteica , Estabilidade Proteica
7.
Diabetes Metab Res Rev ; 34(4): e2991, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29430796

RESUMO

BACKGROUND: RANKL is a key regulator of bone resorption that may also modulate glucose metabolism. Denosumab (DMAb) is a fully human monoclonal antibody that binds RANKL and was associated with fracture risk reduction in the FREEDOM trial. We hypothesized that DMAb treatment decreased fasting serum glucose (FSG) relative to placebo in women with diabetes or prediabetes enrolled in FREEDOM trial. METHODS: Post hoc analysis of FREEDOM, in which 7808 postmenopausal osteoporotic women were randomized to receive DMAb or placebo every 6 months for 36 months. All diabetes group included subjects with a self-report of diabetes, use of antidiabetic medication (ADM), or an FSG ≥ 126 mg/dL at baseline. The diabetes group without prior ADM use included subjects with a self-reported history of diabetes or FSG level ≥ 126 mg/dL at baseline. Prediabetes was defined as an FSG of 100 to 125 mg/dL on no ADM. Average postbaseline FSG across visits was estimated and compared between DMAb and placebo. Main outcome measures are the difference in average postbaseline FSG across follow-up visits between DMAb and placebo. RESULTS: Estimated average postbaseline FSG across visits was not different between DMAb and placebo in either all diabetes group (P = .20) or those with prediabetes (P = .42); in diabetic women not on ADM, estimated average postbaseline FSG across visits was lower with DMAb than placebo (-6.8 mg/dL; 95% CI, -12.6 to -1.0; P = .02). CONCLUSIONS: DMAb did not affect FSG in postmenopausal osteoporotic women with prediabetes or diabetes. There was evidence of modest FSG lowering with DMAb in those with diabetes who were not on ADM. It remains to be determined whether blockade of RANKL has a clinically important effect on glucose metabolism.


Assuntos
Glicemia/metabolismo , Conservadores da Densidade Óssea/uso terapêutico , Denosumab/uso terapêutico , Diabetes Mellitus/metabolismo , Jejum , Hipoglicemiantes/uso terapêutico , Osteoporose Pós-Menopausa/fisiopatologia , Estado Pré-Diabético/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/patologia , Feminino , Seguimentos , Hemoglobina A Glicada/análise , Humanos , Pessoa de Meia-Idade , Estado Pré-Diabético/tratamento farmacológico , Estado Pré-Diabético/patologia , Prognóstico
9.
J Bone Miner Res ; 33(2): 190-198, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29105841

RESUMO

Denosumab reduces bone resorption and vertebral and nonvertebral fracture risk. Denosumab discontinuation increases bone turnover markers 3 months after a scheduled dose is omitted, reaching above-baseline levels by 6 months, and decreases bone mineral density (BMD) to baseline levels by 12 months. We analyzed the risk of new or worsening vertebral fractures, especially multiple vertebral fractures, in participants who discontinued denosumab during the FREEDOM study or its Extension. Participants received ≥2 doses of denosumab or placebo Q6M, discontinued treatment, and stayed in the study ≥7 months after the last dose. Of 1001 participants who discontinued denosumab during FREEDOM or Extension, the vertebral fracture rate increased from 1.2 per 100 participant-years during the on-treatment period to 7.1, similar to participants who received and then discontinued placebo (n = 470; 8.5 per 100 participant-years). Among participants with ≥1 off-treatment vertebral fracture, the proportion with multiple (>1) was larger among those who discontinued denosumab (60.7%) than placebo (38.7%; p = 0.049), corresponding to a 3.4% and 2.2% risk of multiple vertebral fractures, respectively. The odds (95% confidence interval) of developing multiple vertebral fractures after stopping denosumab were 3.9 (2.1-7. 2) times higher in those with prior vertebral fractures, sustained before or during treatment, than those without, and 1.6 (1.3-1.9) times higher with each additional year of off-treatment follow-up; among participants with available off-treatment total hip (TH) BMD measurements, the odds were 1.2 (1.1-1.3) times higher per 1% annualized TH BMD loss. The rates (per 100 participant-years) of nonvertebral fractures during the off-treatment period were similar (2.8, denosumab; 3.8, placebo). The vertebral fracture rate increased upon denosumab discontinuation to the level observed in untreated participants. A majority of participants who sustained a vertebral fracture after discontinuing denosumab had multiple vertebral fractures, with greatest risk in participants with a prior vertebral fracture. Therefore, patients who discontinue denosumab should rapidly transition to an alternative antiresorptive treatment. Clinicaltrails.gov: NCT00089791 (FREEDOM) and NCT00523341 (Extension). © 2017 American Society for Bone and Mineral Research.

10.
Lancet Diabetes Endocrinol ; 5(7): 513-523, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28546097

RESUMO

BACKGROUND: Long-term safety and efficacy of osteoporosis treatment are important because of the chronic nature of the disease. We aimed to assess the long-term safety and efficacy of denosumab, which is widely used for the treatment of postmenopausal women with osteoporosis. METHODS: In the multicentre, randomised, double-blind, placebo-controlled, phase 3 FREEDOM trial, postmenopausal women aged 60-90 years with osteoporosis were enrolled in 214 centres in North America, Europe, Latin America, and Australasia and were randomly assigned (1:1) to receive 60 mg subcutaneous denosumab or placebo every 6 months for 3 years. All participants who completed the FREEDOM trial without discontinuing treatment or missing more than one dose of investigational product were eligible to enrol in the open-label, 7-year extension, in which all participants received denosumab. The data represent up to 10 years of denosumab exposure for women who received 3 years of denosumab in FREEDOM and continued in the extension (long-term group), and up to 7 years for women who received 3 years of placebo and transitioned to denosumab in the extension (crossover group). The primary outcome was safety monitoring, comprising assessments of adverse event incidence and serious adverse event incidence, changes in safety laboratory analytes (ie, serum chemistry and haematology), and participant incidence of denosumab antibody formation. Secondary outcomes included new vertebral, hip, and non-vertebral fractures as well as bone mineral density (BMD) at the lumbar spine, total hip, femoral neck, and one-third radius. Analyses were done according to the randomised FREEDOM treatment assignments. All participants who received at least one dose of investigational product in FREEDOM or the extension were included in the combined safety analyses. All participants who enrolled in the extension with observed data were included in the efficacy analyses. The FREEDOM trial (NCT00089791) and its extension (NCT00523341) are both registered with ClinicalTrials.gov. FINDINGS: Between Aug 3, 2004, and June 1, 2005, 7808 women were enrolled in the FREEDOM study. 5928 (76%) women were eligible for enrolment in the extension, and of these, 4550 (77%) were enrolled (2343 long-term, 2207 crossover) between Aug 7, 2007, and June 20, 2008. 2626 women (1343 long-term; 1283 crossover) completed the extension. The yearly exposure-adjusted participant incidence of adverse events for all individuals receiving denosumab decreased from 165·3 to 95·9 per 100 participant-years over the course of 10 years. Serious adverse event rates were generally stable over time, varying between 11·5 and 14·4 per 100 participant-years. One atypical femoral fracture occurred in each group during the extension. Seven cases of osteonecrosis of the jaw were reported in the long-term group and six cases in the crossover group. The yearly incidence of new vertebral fractures (ranging from 0·90% to 1·86%) and non-vertebral fractures (ranging from 0·84% to 2·55%) remained low during the extension, similar to rates observed in the denosumab group during the first three years of the FREEDOM study, and lower than rates projected for a virtual long-term placebo cohort. In the long-term group, BMD increased from FREEDOM baseline by 21·7% at the lumbar spine, 9·2% at total hip, 9·0% at femoral neck, and 2·7% at the one-third radius. In the crossover group, BMD increased from extension baseline by 16·5% at the lumbar spine, 7·4% at total hip, 7·1% at femoral neck, and 2·3% at one-third radius. INTERPRETATION: Denosumab treatment for up to 10 years was associated with low rates of adverse events, low fracture incidence compared with that observed during the original trial, and continued increases in BMD without plateau. FUNDING: Amgen.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Denosumab/uso terapêutico , Osteoporose Pós-Menopausa/tratamento farmacológico , Idoso , Estudos Cross-Over , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Prognóstico , Fatores de Tempo
11.
BMC Musculoskelet Disord ; 18(1): 174, 2017 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-28449657

RESUMO

BACKGROUND: Denosumab treatment for up to 8 years in the FREEDOM study and Extension was associated with low fracture incidence. It was not clear whether subjects who discontinued during the study conduct had a higher risk of fracture than those who remained enrolled, thereby underestimating the true fracture risk for the entire trial cohort. Thus, we explored the influence of early withdrawals on nonvertebral fracture incidence during the Extension study. METHODS: To understand the potential effect of depletion of susceptible subjects on fracture incidence, we first evaluated subject characteristics in patients who were enrolled in the Extension vs those who were not. We subsequently employed a Kaplan-Meier multiple imputation (KMMI) approach to consider subjects who discontinued as if they remained enrolled with a 0%, 20%, 50%, and 100% increase in fracture risk compared with participants remaining on study. RESULTS: Extension enrollees were generally similar to nonparticipants in median age (71.9 and 73.1 years, respectively), mean total hip bone mineral density T-score (-1.9 and -2.0, respectively), and probability of fracture risk by Fracture Risk Assessment Tool (FRAX®) at FREEDOM baseline (16.9% and 17.7% for major osteoporotic fracture and 6.7% and 7.4% for hip fracture, respectively). When we assumed a doubled fracture risk (100% increase) after discontinuation in KMMI analyses, nonvertebral fracture rate estimates were only marginally higher than the observed rates for both the crossover group (10.32% vs 9.16%, respectively) and the long-term group (7.63% vs 6.63%, respectively). CONCLUSION: The observation of continued denosumab efficacy over 8 years of treatment was robust and does not seem to be explained by depletion of susceptible subjects. TRIAL REGISTRATION: ClincalTrials.gov registration number NCT00523341 ; registered August 30, 2007.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Denosumab/uso terapêutico , Fraturas do Quadril/tratamento farmacológico , Fraturas por Osteoporose/tratamento farmacológico , Pacientes Desistentes do Tratamento , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/epidemiologia , Resultado do Tratamento
12.
J Bone Miner Res ; 32(7): 1481-1485, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28277603

RESUMO

Denosumab is a fully human monoclonal antibody against receptor activator of NF-κB ligand (RANKL) that decreases osteoclast formation, function and survival, and is approved for the treatment of postmenopausal women with osteoporosis at increased or high risk for fracture, among other indications. During the pivotal 3-year fracture trial FREEDOM, denosumab 60 mg subcutaneously every 6 months significantly reduced new vertebral (68%), hip (40%), and nonvertebral (20%) fractures; increased bone mineral density (BMD); and reduced bone turnover markers compared with placebo in postmenopausal women with osteoporosis. Questions have arisen regarding imbalances of certain low-frequency adverse events (AEs) observed in FREEDOM, as well as the top 5 most frequent adverse reactions listed in the United States prescribing information (USPI; back pain, pain in extremity, musculoskeletal pain, hypercholesterolemia, and cystitis). We examined the incidences of these AEs in women who originally received placebo during FREEDOM and then received denosumab for up to 3 years during the FREEDOM Extension (Crossover Group). This provided a unique opportunity for comparison with the original 3-year denosumab FREEDOM observations. We also examined the incidences of these AEs over 6 years of denosumab treatment (Long-term Group; ie, comparing a second 3 years of treatment with findings in the first 3 years). There was no indication of increasing trends regarding the imbalances of either low-frequency AEs or common AEs observed in FREEDOM. © 2017 American Society for Bone and Mineral Research.


Assuntos
Denosumab/administração & dosagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Denosumab/efeitos adversos , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/epidemiologia , Osteoporose Pós-Menopausa/metabolismo , Osteoporose Pós-Menopausa/patologia , Estados Unidos/epidemiologia
13.
J Bone Miner Res ; 31(10): 1827-1834, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27082709

RESUMO

Hip fractures account for over one-half the morbidity, mortality, and cost associated with osteoporosis. Fragility of the proximal femur is the result of rapid and unbalanced bone remodeling events that excavate more bone than they deposit, producing a porous, thinned, and fragile cortex. We hypothesized that the slowing of remodeling during treatment with denosumab allows refilling of the many cavities excavated before treatment now opposed by excavation of fewer new resorption cavities. The resulting net effect is a reduction in cortical porosity and an increase in proximal femur strength. Images were acquired at baseline and 36 months using multidetector CT in 28 women receiving denosumab and 22 women receiving placebo in a substudy of FREEDOM, a randomized, double-blind, placebo-controlled trial involving women with postmenopausal osteoporosis. Porosity was quantified using StrAx1.0 software. Strength was estimated using finite element analysis. At baseline, the higher the serum resorption marker, CTx, the greater the porosity of the total cortex (r = 0.34, p = 0.02), and the higher the porosity, the lower the hip strength (r = -0.31, p = 0.03). By 36 months, denosumab treatment reduced porosity of the total cortex by 3.6% relative to baseline. Reductions in porosity relative to placebo at 36 months were 5.3% in total cortex, 7.9% in compact-appearing cortex, 5.6% in outer transitional zone, and 1.8% in inner transitional zone (all p < 0.01). The improvement in estimated hip integral strength of 7.9% from baseline (p < 0.0001) was associated with the reduction in total porosity (r = -0.41, p = 0.03). In summary, denosumab reduced cortical porosity of the proximal femoral shaft, resulting in increased mineralized matrix volume and improved strength, changes that may contribute to the reduction in hip and nonvertebral fractures reported with denosumab therapy. © 2016 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).


Assuntos
Denosumab/administração & dosagem , Colo do Fêmur , Fraturas do Quadril , Menopausa , Osteoporose Pós-Menopausa , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/metabolismo , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/etiologia , Fraturas do Quadril/metabolismo , Fraturas do Quadril/prevenção & controle , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/metabolismo , Porosidade , Tomografia Computadorizada por Raios X
14.
Vet Med Sci ; 2(2): 125-135, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-29067186

RESUMO

The use of mycophenolate mofetil (MMF) for a variety of immune-mediated diseases in veterinary medicine has been described. However, there is only a small number of cases documenting its use in dogs with meningoencephalomyelitis of unknown aetiology (MUE). We hypothesized that the use of MMF and corticosteroids in dogs with MUE results in comparable survival data to other published treatment protocols and is associated with limited adverse effects. A retrospective study of medical case records of dogs clinically diagnosed with MUE recorded signalment, neuroanatomic localization, magnetic resonance imaging findings, cerebrospinal fluid analysis results, medications administered, follow-up neurologic examinations, survival and adverse events. Variables were compared between dogs which were treated with MMF within 30 days of diagnosis (immediate group) vs. dogs in which MMF therapy was started >30 days after diagnosis (delayed group). Twenty-five cases of MUE were identified. The overall median survival time from diagnosis was 731 days (range 43-1672 days). After 1 month of MMF treatment, 92% of dogs showed improvement on a neurological examination. There was no significant effect of any recorded parameter on survival, including delayed vs. immediate initiation of MMF treatment. Dogs with delayed treatment had significantly lower clinical remission rates than dogs with immediate treatment at 6 months after starting MMF. Adverse events were identified in two cases (8%) and were characterized by mild gastrointestinal signs (vomiting and decreased appetite). Administration of MMF appears safe in dogs with MUE. The use of MMF results in comparable survival times to alternate immunosuppressive protocols.

15.
Bone ; 81: 122-130, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26141837

RESUMO

Denosumab reduced the incidence of new fractures in postmenopausal women with osteoporosis by 68% at the spine and 40% at the hip over 36 months compared with placebo in the FREEDOM study. This efficacy was supported by improvements from baseline in vertebral (18.2%) strength in axial compression and femoral (8.6%) strength in sideways fall configuration at 36 months, estimated in Newtons by an established voxel-based finite element (FE) methodology. Since FE analyses rely on the choice of meshes, material properties, and boundary conditions, the aim of this study was to independently confirm and compare the effects of denosumab on vertebral and femoral strength during the FREEDOM trial using an alternative smooth FE methodology. Unlike the previous FE study, effects on femoral strength in physiological stance configuration were also examined. QCT data for the proximal femur and two lumbar vertebrae were analyzed by smooth FE methodology at baseline, 12, 24, and 36 months for 51 treated (denosumab) and 47 control (placebo) subjects. QCT images were segmented and converted into smooth FE models to compute bone strength. L1 and L2 vertebral bodies were virtually loaded in axial compression and the proximal femora in both fall and stance configurations. Denosumab increased vertebral body strength by 10.8%, 14.0%, and 17.4% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Denosumab also increased femoral strength in the fall configuration by 4.3%, 5.1%, and 7.2% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Similar improvements were observed in the stance configuration with increases of 4.2%, 5.2%, and 5.2% from baseline (p≤0.0007). Differences between the increasing strengths with denosumab and the decreasing strengths with placebo were significant starting at 12 months (vertebral and femoral fall) or 24 months (femoral stance). Using an alternative smooth FE methodology, we confirmed the significant improvements in vertebral body and proximal femur strength previously observed with denosumab. Estimated increases in strength with denosumab and decreases with placebo were highly consistent between both FE techniques.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Denosumab/uso terapêutico , Análise de Elementos Finitos , Fraturas por Osteoporose/prevenção & controle , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Idoso , Feminino , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Humanos , Imagem Tridimensional , Osteoporose Pós-Menopausa/complicações , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/efeitos dos fármacos , Tomografia Computadorizada por Raios X
17.
J Bone Miner Res ; 30(1): 46-54, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25088963

RESUMO

Women with osteoporosis treated for 36 months with twice-yearly injections of denosumab sustained fewer hip fractures compared with placebo. Treatment might improve femoral bone at locations where fractures typically occur. To test this hypothesis, we used 3D cortical bone mapping of postmenopausal women with osteoporosis to investigate the timing and precise location of denosumab versus placebo effects in the hips. We analyzed clinical computed tomography scans from 80 female participants in FREEDOM, a randomized trial, wherein half of the study participants received subcutaneous denosumab 60 mg twice yearly and the others received placebo. Cortical 3D bone thickness maps of both hips were created from scans at baseline, 12, 24, and 36 months. Cortical mass surface density maps were also created for each visit. After registration of each bone to an average femur shape model followed by statistical parametric mapping, we visualized and quantified statistically significant treatment effects. The technique allowed us to pinpoint systematic differences between denosumab and control and to display the results on a 3D average femur model. Denosumab treatment led to an increase in femoral cortical mass surface density and thickness, already evident by the third injection (12 months). Overall, treatment with denosumab increased femoral cortical mass surface density by 5.4% over 3 years. One-third of the increase came from increasing cortical density, and two-thirds from increasing cortical thickness, relative to placebo. After 36 months, cortical mass surface density and thickness had increased by up to 12% at key locations such as the lateral femoral trochanter versus placebo. Most of the femoral cortex displayed a statistically significant relative difference by 36 months. Osteoporotic cortical bone responds rapidly to denosumab therapy, particularly in the hip trochanteric region. This mechanism may be involved in the robust decrease in hip fractures observed in denosumab-treated women at increased risk of fracture.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Colo do Fêmur , Osteoporose Pós-Menopausa , Idoso , Idoso de 80 Anos ou mais , Denosumab , Feminino , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/metabolismo , Seguimentos , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/metabolismo , Fraturas do Quadril/prevenção & controle , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/metabolismo , Tomografia Computadorizada por Raios X
18.
J Bone Miner Res ; 29(2): 450-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23873632

RESUMO

Atherosclerosis and osteoporosis are chronic diseases that progress with age, and studies suggest aortic calcification, an indicator of atherosclerosis, is inversely associated with bone mineral density (BMD). The osteoprotegerin (OPG)/receptor activator of NF-κB (RANK)/RANK ligand (RANKL) system has been proposed as a shared regulatory system for bone and vasculature. Denosumab (DMAb), a monoclonal antibody against RANKL, improved BMD and reduced fracture risk in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. We evaluated whether or not treatment with DMAb influenced progression of aortic calcification (AC) and incidence of cardiovascular (CV) adverse events. We included 2363 postmenopausal women with osteoporosis (1142 placebo, 1221 DMAb), selected from 7808 participants in the FREEDOM trial (3906 placebo, 3902 DMAb), at high risk of CV events according to modified Raloxifene Use for the Heart (RUTH) criteria. CV adverse events were reported by participants. AC scores were assessed using a semiquantitative method from lateral spine X-rays. Change in AC score from baseline to 12 (n = 1377), 24 (n = 1231), and 36 months (n = 1045) was calculated as AC score at follow-up minus AC score at baseline. AC progression was defined as change in AC score >0. Baseline characteristics, CV risk factors, and AC scores were similar between treatment groups. Mean age of participants was 74 years (range, 60-90), 88% were white, and 77% had AC score >0 at baseline. Frequency of AC progression over 3 years did not differ between women in placebo (22%) and DMAb (22%) groups (p = 0.98). AC progression did not differ between treatment groups when analyzed by baseline estimated glomerular filtration rate or by baseline AC scores. Frequency of CV adverse events did not differ between placebo (40%) and DMAb (38%) groups (p = 0.26). In conclusion, DMAb treatment had no effect on progression of AC or incidence of CV adverse events compared to placebo.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Doenças da Aorta/tratamento farmacológico , Osteoporose Pós-Menopausa/tratamento farmacológico , Ligante RANK/antagonistas & inibidores , Calcificação Vascular/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Doenças da Aorta/complicações , Doenças da Aorta/patologia , Denosumab , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/patologia , Calcificação Vascular/complicações , Calcificação Vascular/patologia
19.
J Clin Endocrinol Metab ; 98(11): 4483-92, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23979955

RESUMO

CONTEXT: The Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) extension is evaluating the long-term efficacy and safety of denosumab for up to 10 years. OBJECTIVE: The objective of the study was to report results from the first 3 years of the extension, representing up to 6 years of denosumab exposure. DESIGN, SETTING, AND PARTICIPANTS: This was a multicenter, international, open-label study of 4550 women. INTERVENTION: Women from the FREEDOM denosumab group received 3 more years of denosumab for a total of 6 years (long-term) and women from the FREEDOM placebo group received 3 years of denosumab (crossover). MAIN OUTCOME MEASURES: Bone turnover markers (BTMs), bone mineral density (BMD), fracture, and safety data are reported. RESULTS: Reductions in BTMs were maintained (long-term) or achieved rapidly (crossover) after denosumab administration. In the long-term group, BMD further increased for cumulative 6-year gains of 15.2% (lumbar spine) and 7.5% (total hip). During the first 3 years of denosumab treatment, the crossover group had significant gains in lumbar spine (9.4%) and total hip (4.8%) BMD, similar to the long-term group during the 3-year FREEDOM trial. In the long-term group, fracture incidences remained low and below the rates projected for a virtual placebo cohort. In the crossover group, 3-year incidences of new vertebral and nonvertebral fractures were similar to those of the FREEDOM denosumab group. Incidence rates of adverse events did not increase over time. Six participants had events of osteonecrosis of the jaw confirmed by adjudication. One participant had a fracture adjudicated as consistent with atypical femoral fracture. CONCLUSION: Denosumab treatment for 6 years remained well tolerated, maintained reduced bone turnover, and continued to increase BMD. Fracture incidence remained low.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Fraturas Ósseas/prevenção & controle , Osteoporose Pós-Menopausa/tratamento farmacológico , Ligante RANK/antagonistas & inibidores , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Estudos Cross-Over , Denosumab , Feminino , Fraturas Ósseas/epidemiologia , Humanos , Incidência , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/epidemiologia , Placebos , Fatores de Risco , Tempo
20.
J Am Vet Med Assoc ; 242(10): 1398-404, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23634685

RESUMO

CASE DESCRIPTION: A 40.3-kg (88.7-lb) 6-year-old spayed female Labrador Retriever was evaluated because of acute unilateral epistaxis. CLINICAL FINDINGS: During the initial evaluation of the dog, systemic hypertension and a left adrenal gland mass were detected. The left adrenal gland mass was surgically removed; results of histologic examination of the mass indicated it was a pheochromocytoma. Ten months later, the dog was evaluated because of persistent systemic hypertension and development of polyuria, polydipsia, and excessive panting. Abdominal ultrasonography revealed a mass in the cranial aspect of the right adrenal gland; results of MRI suggested the mass was a malignant tumor. TREATMENT AND OUTCOME: Epistaxis resolved after treatment and resolution of severe systemic hypertension. A partial right adrenalectomy was performed to remove the right adrenal gland mass. Results of histologic examination of the mass indicated it was a well-differentiated carcinoma of the cortex of the adrenal gland. Results of ACTH stimulation tests after surgery indicated the dog had adequate adrenal gland function. CLINICAL RELEVANCE: Partial adrenalectomy may be a safe and feasible treatment option to preserve adrenal gland function in dogs with small eccentrically located adrenal gland masses, particularly for dogs that have undergone removal of the contralateral adrenal gland.


Assuntos
Neoplasias das Glândulas Suprarrenais/veterinária , Glândulas Suprarrenais/fisiologia , Adrenalectomia/veterinária , Doenças do Cão/cirurgia , Feocromocitoma/veterinária , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/cirurgia , Animais , Cães , Feminino , Feocromocitoma/complicações , Feocromocitoma/cirurgia , Prednisona/uso terapêutico
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