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Objective: As a novel oral agent in treating anemia of chronic kidney disease (CKD), several clinical trials of vadadustat have been conducted to compare with darbepoetin alfa. This study systematically reviews and investigates the efficacy and safety of vadadustat in the anemia treatment with different duration in both nondialysis-dependent CKD (NDD-CKD) and dialysis-dependent CKD (DD-CKD). Methods: Several main databases were searched for randomized controlled trials (RCTs) reporting vadadustat vs darbepoetin alfa for anemia patients with CKD. The outcome indicators were focused on hemoglobin (Hb), the percentage of patients within the target Hb, the need for RBC (Red Blood Cell) transfusions, and serious adverse events (SAEs). Results: Four eligible studies with 8,026 participants were included. The changes of Hb levels from the baseline in the darbepoetin alfa group were significantly higher than that in the vadadustat group with DD-CKD (mean difference (MD) − 0.19, [95% confidence interval (CI), − 0.21 to − 0.17], p < 0.0001). In NDD-CKD patients, the changes of Hb levels in the two groups are not significantly different (MD = − 0.06, [95% CI, − 0.18 to 0.05], p = 0.006), especially, during the treatment duration of 20–36 weeks (MD = 0.02, [95% CI, − 0.04 to 0.08], p = 0.51). The percentage of patients within the target Hb was significantly lower in the vadadustat group than that in the darbepoetin alfa group in DD-CKD patients (MD = 0.9, [95% CI, 0.86 to 0.94], p < 0.00001), while in NDD-CKD patients, there was no significant difference (MD = 1.05, [95% CI, 0.99 to 1.12], p < 0.00001). In terms of safety, the two agents had no significant difference in the incidence of RBC transfusions and SAEs (RR = 1.26 [95% CI, 0.99 to 1.61], p = 0.52; RR = 0.97, [95% CI, 0.94 to 1.01], p = 0.19; respectively). Conclusion: Compared to darbepoetin alfa, vadadustat had the same effect in raising the hemoglobin level in NDD-CKD patients in the short term. Vadadustat may become an effective and safe alternative for the treatment of patients with anemia and CKD, especially in NDD-CKD patients. As the application of vadadustat is still under exploration, future research should compensate for the limitations of our study to estimate the vadadustat's value. [ABSTRACT FROM AUTHOR]

To determine whether or not Darbepoetin alpha (DA) was non-inferior to recombinant human erythropoietin (rHuEPO) in the treatment of anemia in children with chronic kidney disease (CKD) stage 3–5 (on or not on dialysis). This was a randomized, open-label, two-arm, parallel group, active-controlled, non-inferiority trial conducted at a tertiary care center in New Delhi, India. Fifty patients of either gender (aged 1–18 years) with CKD stage 3–5 (on or not on dialysis) who had baseline hemoglobin (Hb) between 9 and 12 g/dL and were on stable erythropoietin therapy for at least 8 weeks were randomized (1:1) to either continue rHuEPO or switch to DA therapy for a period of 28 weeks. Doses were titrated in the initial 23 weeks to maintain the Hb between 11 and 12 g/dL, and efficacy was assessed between weeks 24 and 28. The primary efficacy outcome was the mean change in Hb between baseline and the evaluation period. In the intention-to-treat population (n = 50), the adjusted between-group difference in mean Hb change between the baseline and the evaluation period was 0.131 g/dL (95% CI: − 0.439 to 0.719, p = 0.629). The lower limit of the two-sided 95% CI for the difference in the mean change in Hb between the two treatment groups was well above the pre-specified non-inferiority margin of − 1.0 g/dL. Similar pattern of non-inferiority was seen for per protocol population. The safety profile of DA and rHuEPO was also comparable (injection site pain:rHuEPO-3, DA-7; p-0.296). Conclusion: DA is non-inferior to rHuEPO for the treatment of anemia of CKD (stage 3–5) in pediatric population with a comparable safety profile. Trial registration: ClinicalTrials.gov Identifier: NCT04959578 (retrospectively registered), Date: July 13, 2021. What is Known: • Limited studies showing darbepoetin alpha is effective in children as an erythropoiesis stimulating agent. • No RCT from Indian subcontinent addressing this topic. What is New: • Darbepoetin alpha is non inferior to recombinant human erythropoietin for treatment of anemia in children with CKD stage 3-5 (on or not on dialysis) with safety comparable to recombinant human erythropoietin. • A cost reduction of approximately 8.6% per patient by shifting to darbepoetin alpha. [ABSTRACT FROM AUTHOR]

Darbepoetin alfa (DA) is used to treat anemia in lower-risk (IPSS low or int-1) myelodysplastic syndromes (MDS). However, whether mutations can predict the effectiveness of DA has not been examined. The present study aimed to determine predictive gene mutations. The primary endpoint was a correlation between the presence of highly frequent (≥ 10%) mutations and hematological improvement-erythroid according to IWG criteria 2006 by DA (240 μg/week) until week 16. The study included 79 patients (age 29-90, median 77.0 years; 52 [65.8%] male). Frequently (≥ 10%) mutated genes were SF3B1 (24 cases, 30.4%), TET2 (20, 25.3%), SRSF2 (10, 12.7%), ASXL1 (9, 11.4%), and DNMT3A (8, 10.1%). Overall response rate to DA was 70.9%. Multivariable analysis including baseline erythropoietin levels and red blood cell transfusion volumes as variables revealed that erythropoietin levels and mutations of ASXL1 gene were significantly associated with worse response (odds ratio 0.146, 95% confidence interval 0.042-0.503; p = 0.0023, odds ratio 0.175, 95% confidence interval 0.033-0.928; p = 0.0406, respectively). This study indicated that anemic patients who have higher erythropoietin levels and harbor ASXL1 gene mutations may respond poorly to DA. Alternative strategies are needed for the treatment of anemia in this population. Trial registration number and date of registration: UMIN000022185 and 09/05/2016. [ABSTRACT FROM AUTHOR]

Darbepoetin alfa is used to treat anemia in patients with chronic renal failure and is a therapeutic glycoprotein with five N-glycosylation sites and one O-glycosylation site. Since the glycosylation of therapeutic proteins is known to affect pharmacokinetics and biological activity, it was wondered how the certain glycosylation structure of darbepoetin alfa affects pharmacokinetics and biological activity. To investigate the effects of glycosylation structures, several darbepoetin alfa samples were generated through the processes slightly modified from HK-DPO production process. Analysis of N-linked glycosylation profiles showed that darbepoetin alfa samples have different proportions of N-acetyllactosamine and O-acetylated sialic acids. Since these structures were known to affect the stability and efficacy of glycoproteins, we evaluated the pharmacokinetics and biological activities of darbepoetin alfa samples. As a result of pharmacokinetics, the time course of the concentration in plasma was similar to that of NESP®, commercially available darbepoetin alfa. Also, the relative AUClast ratio (sample/reference) was ranged from 84% to 114%, which indicated they did not have meaningful differences. For in vitro biological activity, a cell proliferation test was conducted in the EPO-dependent F36E cell-line. An in vivo biological activity test was performed with EP-based assay using B6D2F1 female mice. As a result, the biological activities of each samples were similar to those of reference drug, NESP®. In conclusion, different proportions of N-acetyllactosamine and O-acetylation of sialic acid in darbepoetin alfa did not show any meaningful effects on pharmacokinetics and biological activities. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the clinical efficacy of epoetin alfa and darbepoetin alfa in patients with myelodysplastic syndromes (MDS) in the real-life setting. A total of 204 patients with low-risk or intermediate-1-risk MDS who received epoetin alfa or darbepoetin alfa were included. Hemoglobin levels and transfusion need were recorded before and during 12-month treatment. Hemoglobin levels were significantly higher at each follow up visit when compared to baseline levels in both epoetin alfa (mean ± SD 8.68 ± 1.0 g/dL at baseline vs. 9.83 ± 1.45, 9.99 ± 1.55, 10.24 ± 1.77 and 10.2 ± 1.5 g/dL, respectively) and darbepoetin alfa (8.83 ± 1.09 g/dL at baseline vs. 9.62 ± 1.37, 9.78 ± 1.49, 9.9 ± 1.39 and 10.1 ± 1.5 g/dL, respectively) groups (p < 0.001 for each). Transfusion need significantly decreased from baseline at each study visit in the epoetin alfa group (p < 0.001) and only at the 12th month visit (p < 0.001) in the darbepoetin alfa group. Hemoglobin levels or transfusion need was similar between treatment groups. Overall, 12-month response rate was 58.1% for epoetin alfa and 41.9% for darbepoetin alfa, with no significant difference between treatment groups, whereas higher response rate was noted within the first three months (62.7%) compared to next 9 months (ranged 44.4–60%) of treatment in the epoetin alfa group (p ranged 0.002 to < 0.001). This real-life retrospective study revealed similar efficacy of epoetin alfa and darbepoetin alfa among low risk or intermediate-1 risk MDS patients with no difference in treatment response between treatment groups, whereas a likelihood of earlier treatment response in the epoetin alfa group. [ABSTRACT FROM AUTHOR]

Neonates with Rhesus hemolytic disease can present with anemia beyond 1 wk of age due to bone marrow suppression and low erythropoietin secretion. Erythropoietin stimulating agents (ESA) were tried to manage anemia in these neonates. Darbepoetin alfa (DA) is a long-acting ESA used to treat anemia in premature neonates and in children with chronic kidney disease or on cancer chemotherapy. The authors present their experience of using DA to treat late-onset hyporegenerative anemia in 3 neonates with Rhesus isoimmunization. Darbepoetin alfa 4 mcg/kg was given subcutaneously at a 1–2-wk interval to target hemoglobin of 10–12 g/dL. No adverse effects were observed, and the treated infants had a reduced need for the packed red blood cell transfusions. [ABSTRACT FROM AUTHOR]

Introduction: This integrated phase 3 analysis examined efficacy and cardiovascular safety for roxadustat vs erythropoiesis-stimulating agents (ESAs) in dialysis-dependent patients. Methods: Efficacy and safety results from four phase 3, randomized, open-label studies comparing roxadustat to ESAs (PYRENEES, SIERRAS, HIMALAYAS, ROCKIES) in dialysis-dependent patients with anemia of chronic kidney disease (CKD) were evaluated by study, pooled population and in two subgroups: incident dialysis and stable dialysis. The primary efficacy endpoint per study was hemoglobin change from baseline (CFB) to weeks 28–36 using least-squares mean difference (LSMD) without rescue therapy. Pooled safety endpoints included time to major adverse cardiovascular event (MACE; myocardial infarction, stroke, and all-cause mortality [ACM]) and MACE+ (MACE plus congestive heart failure or unstable angina requiring hospitalization), ACM, and treatment-emergent adverse events (TEAEs). MACE and MACE+ were evaluated for non-inferiority at 1.8 and 1.3 margins using hazard ratios (HRs) and 95% confidence intervals (CIs). TEAEs were descriptively summarized. Results: In total, 4714 patients were randomized (2354 roxadustat; 2360 ESA). Hemoglobin CFB to weeks 28–36 achieved non-inferiority for roxadustat vs ESA in each study. Roxadustat was non-inferior to ESA for risks for MACE and MACE+ in the entire cohort (MACE: HR 1.09, 95% CI 0.95–1.26; MACE+ : HR 0.98, 95% CI 0.86–1.11) and similar to the incident dialysis and stable dialysis subgroups; ACM results were consistent with MACE and MACE+ (HR 1.13, 95% CI 0.95–1.34). TEAEs were generally comparable between groups. Conclusion: Roxadustat improved hemoglobin similarly to ESA while demonstrating comparable cardiovascular and overall safety profiles in a wide spectrum of dialysis-dependent patients with anemia of CKD. Roxadustat represents an oral alternative to ESAs for achieving a target hemoglobin for anemia of CKD in dialysis-dependent patients. [ABSTRACT FROM AUTHOR]

Background: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with cardiovascular events and poor renal outcome in patients with chronic kidney disease (CKD). This study aimed to investigate the initial responsiveness to darbepoetin alfa (DA) and its contributing factors using the data from the BRIGHTEN. Methods: Of 1980 patients enrolled at 168 facilities, 1695 were included in this analysis [285 patients were excluded mainly due to lack of hemoglobin (Hb) values]. The initial ESA response index (iEResI) was defined as a ratio of Hb changes over 12 weeks after DA administration per weight-adjusted total DA dose and contributing factors to iEResI were analyzed. Results: The mean age was 70 ± 12 years (male 58.8%; diabetic nephropathy 27.6%). The median creatinine and mean Hb levels at DA initiation were 2.62 mg/dL and 9.8 g/dL, respectively. The most frequent number of DA administration during 12 weeks was 3 times (41.1%), followed by 4 (15.6%) times with a wide distribution of the total DA dose (15–900 μg). Remarkably, 225 patients (13.3%) did not respond to DA. Multivariate analysis showed that male gender, hypoglycemic agent use, iron supplementation, high eGFR, low Hb, low CRP, low NT-proBNP, and low urinary protein–creatinine ratio were independently associated with better initial response to DA (P = < 0.0001, 0.0108, < 0.0001, 0.0476, < 0.0001, 0.0004, 0.0435, and 0.0009, respectively). Conclusions: Non-responder to DA accounted for 13.3% of patients with non-dialysis CKD. Iron supplementation, low CRP, low NT-proBNP, and less proteinuria were predictive and modifiable factors associated with better initial response to DA. [ABSTRACT FROM AUTHOR]

Objective: This study compared the pharmacokinetic (PK), pharmacodynamic (PD), and safety properties of the test (CJ-40001) and reference (NESP®) versions of darbepoetin alfa following a single subcutaneous (SC) or intravenous (IV) administration in healthy male subjects.Methods: A single-blind, randomized, single-dose, two-period, two-intervention crossover study was conducted, with two separate parts consisting of SC or IV administration. In each period, either a test or reference product was administered via the SC or IV route. Serial blood samples for PK analysis and the reticulocyte, hematocrit, hemoglobin, and red blood cell counts for PD analysis were collected for up to 360 or 264 h after SC or IV administration, respectively. The PK and PD parameters were calculated using non-compartmental methods. The 90% confidence intervals of the geometric mean ratios for the PK and PD parameters between the two interventions were estimated. Safety and anti-drug antibody profile assessments were performed.Results: The mean darbepoetin alfa concentration-time profiles were comparable between the two products for SC and IV administration. Additionally, the PD and safety profiles were similar between the two products. Anti-drug antibody reactivity was negative for all samples from both intervention groups for SC and IV administration. The time-matched serum darbepoetin alfa concentration and the PD markers presented a counter-clockwise hysteresis, which suggests a time delay between the exposure and response.Conclusion: The test and reference darbepoetin alfa formulations had similar PK, PD, and safety profiles. Thus, it is expected that the two formulations are able to be used interchangeably in clinical settings.ClinicalTrials.gov Identifier: NCT03542916. [ABSTRACT FROM AUTHOR]

Background: This post-marketing surveillance (PMS) study evaluated the safety and effectiveness of long-term darbepoetin alfa (darbepoetin) for the treatment of renal anemia in Japanese non-dialysis chronic kidney disease patients.Methods: Patients were treated with darbepoetin and followed up for 3 years. Adverse events (AEs), adverse drug reactions (ADRs), hemoglobin (Hb) levels, and renal function were assessed. Patients were stratified by Hb level at the time of occurrence of cardiovascular-related AEs. Statistical analyses were performed to explore factors affecting the occurrence of AEs, cardiovascular-related AEs, and composite renal endpoints.Results: In the safety analysis set (5547 patients), AEs and ADRs occurred in 44.4 and 7.1% of patients, respectively. Cardiovascular-related AEs were observed in 12.6% of the overall population. The proportion of patients who presented cardiovascular-related AEs was lower among those with a higher Hb level at the time of occurrence. In the effectiveness analysis set (5024 patients), mean Hb levels remained between 10.0 and 10.6 g/dL (Weeks 4-156). Three months after darbepoetin administration, patients with Hb ≥ 11 g/dL presented fewer composite renal endpoints than those with Hb < 11 g/dL (p = 0.0013), and the cumulative proportion of renal survival was higher in those with Hb ≥ 11 g/dL vs. Hb < 11 g/dL (p < 0.0001).Conclusions: This PMS study showed the safety and effectiveness of long-term use of darbepoetin in a large number of patients. Patients with Hb ≥ 11 g/dL presented fewer composite renal endpoints than those with Hb < 11 g/dL, without an increase in the incidence of cardiovascular-related AEs. [ABSTRACT FROM AUTHOR]

Purpose: The primary objective of this study was to evaluate the compliance of Romanian physicians with the national therapeutic protocol and international guidelines on treatment with erythropoiesis-stimulating agents in anemic cancer patients receiving chemotherapy. The secondary objective was to assess the hemoglobin (Hb) level change due to anemia treatment and safety of darbepoetin alfa.Methods: This was a single-arm, prospective, longitudinal, multicenter, observational study in patients with nonmyeloid malignancies and symptomatic chemotherapy-induced anemia treated concomitantly with darbepoetin alfa. Patients were followed for the duration of chemotherapy, but no shorter than three and no longer than eight cycles, irrespective of their exposure to darbepoetin alfa.Results: In this study, 497 patients with a mean age of 60.6 years were analyzed. Most patients (80.7%) were initiated on darbepoetin alfa at a Hb of 9-11 g/dL, congruent with recommendations. The median Hb increased by 0.9 g/dL between baseline and week 12. Hb target achievement was higher among patients treated according to guidelines than those initiated at Hb < 9 g/dL. A similar trend was observed for red blood cell transfusion requirements. No new safety signals were reported for darbepoetin alfa.Conclusions: The majority of patients were treated according to national and international recommendations. Guideline adherence was associated with more frequent achievement of Hb targets and lower red blood cell transfusion requirements compared with patients starting anemia treatment with darbepoetin alfa at lower-than-recommended Hb levels. [ABSTRACT FROM AUTHOR]

Background: For regulatory approval, the comparability of a biosimilar product to an originator product should be ensured through thorough physicochemical and biological characterization.Objective: To evaluate the biosimilarity between LBDE, the proposed biosimilar darbepoetin alfa, and NESP®, its originator, we performed a comprehensive physicochemical and biological characterization study.Methods: Primary and higher-order protein structures were analyzed using Lys-C peptide mapping with liquid chromatography-mass spectrometry (LC-MS), disulfide bond identification, circular dichroism, and fluorescence spectroscopy. Glycosylation and isoform distribution were analyzed using MS, LC, and capillary zone electrophoresis. Size variants were evaluated with size-exclusion chromatography-high-performance liquid chromatography (SEC-HPLC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Biological characterization included binding affinity for human erythropoietin receptor, in vitro cell proliferation, and in vivo potency. Pharmacokinetics (PK) were evaluated using rats through two injection routes.Results: Non-reducing and reducing Lys-C peptide mapping showed a highly similar peak profile, confirming that LBDE and NESP® have the same primary structure and disulfide bonds. Glycosylation and isoform analyses showed that the attached N-glycan and O-glycan structures were the same and their relative contents were similar. Spectroscopic analysis of LBDE showed indistinguishable spectra with NESP®. For both LBDE and NESP®, a very small amount of size variants was found in SEC-HPLC, and no minor bands were detected in SDS-PAGE. Furthermore, LBDE did not show any difference with NESP® in the in vitro and in vivo functional analyses. PK parameters of LBDE were in good agreement with those of NESP®.Conclusion: LBDE shows high similarity to NESP® with regard to structure and function. [ABSTRACT FROM AUTHOR]

Background: For regulatory approval, the comparability of a biosimilar product to an originator product should be ensured through thorough physicochemical and biological characterization.Objective: To evaluate the biosimilarity between LBDE, the proposed biosimilar darbepoetin alfa, and NESP®, its originator, we performed a comprehensive physicochemical and biological characterization study.Methods: Primary and higher-order protein structures were analyzed using Lys-C peptide mapping with liquid chromatography-mass spectrometry (LC-MS), disulfide bond identification, circular dichroism, and fluorescence spectroscopy. Glycosylation and isoform distribution were analyzed using MS, LC, and capillary zone electrophoresis. Size variants were evaluated with size-exclusion chromatography-high-performance liquid chromatography (SEC-HPLC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Biological characterization included binding affinity for human erythropoietin receptor, in vitro cell proliferation, and in vivo potency. Pharmacokinetics (PK) were evaluated using rats through two injection routes.Results: Non-reducing and reducing Lys-C peptide mapping showed a highly similar peak profile, confirming that LBDE and NESP® have the same primary structure and disulfide bonds. Glycosylation and isoform analyses showed that the attached N-glycan and O-glycan structures were the same and their relative contents were similar. Spectroscopic analysis of LBDE showed indistinguishable spectra with NESP®. For both LBDE and NESP®, a very small amount of size variants was found in SEC-HPLC, and no minor bands were detected in SDS-PAGE. Furthermore, LBDE did not show any difference with NESP® in the in vitro and in vivo functional analyses. PK parameters of LBDE were in good agreement with those of NESP®.Conclusion: LBDE shows high similarity to NESP® with regard to structure and function. [ABSTRACT FROM AUTHOR]

Background: Renal anemia is an important complication in non-dialysis chronic kidney disease (CKD) patients as well as in dialysis patients. Although recombinant human erythropoietin has dramatically improved prognosis and quality of life in these patients, there have been issues among non-dialysis CKD patients who exhibit hyporesponsiveness to erythropoiesis-stimulating agent (ESA). The causes and definition of ESA hyporesponsiveness, as well as the incidence of renal and cardiovascular disease (CVD) events in such patients, are yet to be clarified.Methods: This ongoing trial is a multicenter, prospective, observational study of non-dialysis CKD patients with renal anemia. The primary objective is to survey the current realities of the therapy with ESA in Japan and evaluate the correlation between hyporesponsiveness to darbepoetin alfa and CKD progression. The secondary objective is to investigate relationship between ESA hyporesponsiveness and CVD events based on the clinical situation in Japan, and to explore an ESA response index.Results: The subjects consist of CKD patients with estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2 who present renal anemia. The target number of registered cases is 2000 patients, based on estimates of incidences of renal and CVD events from past studies. Renal function and CVD events will be observed for 96 weeks after the initiation of darbepoetin alfa administration. Definitions of ESA hyporesponsiveness will also be investigated.Conclusion: By clarifying markers and factors involved in ESA hyporesponsiveness and their relationships with renal and CVD events, this ongoing study aims to improve evidence-based therapies for renal anemia in non-dialysis CKD patients. [ABSTRACT FROM AUTHOR]

Background: Darbepoetin alfa is a commonly prescribed erythropoiesis-stimulating agent (ESA) for correcting anemia in pediatric chronic kidney disease (CKD) patients. However, little information exists on its use in ESA-naïve patients. This study evaluated the efficacy and safety of darbepoetin alfa in pediatric patients initiating ESA therapy. Methods: One-hundred sixteen pediatric ESA-naïve subjects (aged 1-18 years) with CKD stages 3-5D and hemoglobin (Hb) <10 g/dl from 43 centers in the US, Europe, and Mexico were randomized by age (three groups) and dialysis status (yes vs. no) to receive darbepoetin alfa once weekly (QW) or every 2 weeks (Q2W) subcutaneously (not on dialysis and peritoneal dialysis subjects) and intravenously (hemodialysis subjects). The drug was titrated to achieve Hb levels of 10.0-12.0 g/dl over 25 weeks. Patient- and parent-reported health-related outcomes were measured by the Pediatric Quality of Life Inventory (PedsQL™) in children ≥2 years. Results: In both groups, mean Hb concentrations increased to ≥11.0 g/dl over the first 3 months of treatment and remained stable within the 10.0-12.0 g/dl target range. The median time to achieve hemoglobin ≥10 g/dl was slightly longer for subjects <12 years (QW and Q2W, both 28 days) vs. those ≥12 years (23 and 22 days, respectively). Adverse event profiles were similar between groups, with QW, four (7%) and Q2W, five (9%). PedsQL™ scores showed modest increases. Conclusions: Darbepoetin alfa can be safely administered either QW or Q2W to ESA-naïve pediatric patients with CKD-related anemia to achieve Hb targets of 10.0-12.0 g/dl. [ABSTRACT FROM AUTHOR]

Purpose: Erythropoiesis-stimulating agents (ESAs) are often used in treatment of patients with chemotherapy-induced anemia. Many studies have demonstrated an improved hemoglobin (Hb) response when ESA is combined with intravenous iron supplementation and a higher effectiveness of intravenous iron over traditional oral iron formulations. A new formulation of oral sucrosomial iron featuring an increased bioavailability compared to traditional oral formulations has recently become available and could provide a valid alternative to those by intravenous (IV) route. Our study evaluated the performance of sucrosomial iron versus intravenous iron in increasing hemoglobin in anemic cancer patients receiving chemotherapy and darbepoetin alfa, as well as safety, need of transfusion, and quality of life (QoL).Materials and Methods: The present study considered a cohort of 64 patients with chemotherapy-related anemia (Hb >8 g/dL <10 g/dL) and no absolute or functional iron deficiency, scheduled to receive chemotherapy and darbepoetin. All patients received darbepoetin alfa 500 mcg once every 3 weeks and were randomly assigned to receive 8 weeks of IV ferric gluconate 125 mg weekly or oral sucrosomial iron 30 mg daily. The primary endpoint was to demonstrate the performance of oral sucrosomial iron in improving Hb response, compared to intravenous iron. The Hb response was defined as the Hb increase ≥2 g/dL from baseline or the attainment Hb ≥ 12 g/dL.Results: There was no difference in the Hb response rate between the two treatment arms. Seventy one percent of patients treated with IV iron achieved an erythropoietic response, compared to 70% of patients treated with oral iron. By conventional criteria, this difference is considered to be not statistically significant. There were also no differences in the proportion of patients requiring red blood cell transfusions and changes in QoL. Sucrosomial oral iron was better tolerated.Conclusion: In cancer patients with chemotherapy-related anemia receiving darbepoetin alfa, sucrosomial oral iron provides similar increase in Hb levels and Hb response, with higher tolerability without the risks or side effects of IV iron. [ABSTRACT FROM AUTHOR]

Background and Objective We compared the hemoglobin-maintaining effects between continuous erythropoietin receptor activator (CERA) and darbepoetin-α (DA) in patients with chronic kidney disease (CKD) during the 3 months before dialysis initiation. Methods This study was conducted with 37 CERA-administered patients and 26 DA-administered patients who had initiated dialysis at a participating facility between January 2012 and December 2014. We investigated clinical laboratory data 3 months before and at dialysis initiation, and compared these data between the CERA and DA groups. Results No significant differences in hemoglobin level or reticulocyte count were found between the two groups 3 months before dialysis initiation. However, at dialysis initiation, the hemoglobin level (CERA 9.82 ± 1.52 vs. DA 8.79 ± 1.07 g/dL; P = 0.003) and the reticulocyte count (CERA 5.21 ± 2.95 vs. DA 3.15 ± 1.62 9 104/µL; P = 0.004) were significantly higher in the CERA group than in the DA group. Moreover, the extent of changes in the erythropoietin resistance index during the 3 months before dialysis initiation was significantly increased in the DA group compared with the CERA group. Conclusions Our results suggest that CERA may be more effective than DA in maintaining hemoglobin levels in patients with CKD during 3 months before dialysis initiation. [ABSTRACT FROM AUTHOR]

Darbepoetin alfa is a biopharmaceutical glycoprotein that stimulates erythropoiesis and is used to treat anemia, which associated with renal failure and cancer chemotherapy. We herein describe the structural characterization of recombinant darbepoetin alfa produced by Leishmania tarentolae T7-TR host. The DNA expression cassette was integrated into the L. tarentolae genome through homologous recombination. Transformed clones were selected by antibiotic resistance, diagnostic PCRs, and protein expression analysis. The structure of recombinant darbepoetin alfa was analyzed by isoelectric focusing, ultraviolet-visible spectrum, and circular dichroism (CD) spectroscopy. Expression analysis showed the presence of a protein band at 40 kDa, and its expression level was 51.2 mg/ml of culture medium. Darbepoetin alfa have 5 isoforms with varying degree of sialylation. The UV absorption and CD spectra were analogous to original drug (Aranesp), which confirmed that the produced protein was darbepoetin alfa. Potency test results revealed that the purified protein was biologically active. In brief, the structural and biological characteristics of expressed darbepoetin alfa were very similar to Aranesp which has been normally expressed in CHO. Our data also suggest that produced protein has potential to be developed for clinical use. [ABSTRACT FROM AUTHOR]

Background: Renal anemia complicated with chronic kidney disease is usually treated with erythropoiesis-stimulating agents (ESAs). However, few studies have compared the early response of hemoglobin (Hb) to different kinds of ESAs. Methods: The effects of three types of ESAs-epoetin alfa or beta (EPO), darbepoetin alfa (DPO), and epoetin beta pegol (EPObp)-on renal anemia were followed in 416 pre-dialysis chronic kidney disease (CKD) patients. After the initial 12-week administration of ESAs, ΔHb/ESA dose/kg was calculated as an index of efficacy of each ESA. Furthermore, independent variables associated with ΔHb/ESA dose/kg (dependent variable) were determined using multiple linear regression analysis. The ten independent variables selected for analysis were: presence of diabetic nephropathy, estimated glomerular filtration rate (eGFR), Hb, albumin, iron (Fe), transferrin saturation (TSAT), ferritin, phosphate (P), intact parathyroid hormone (iPTH), and C-reactive protein. Results: The efficacy of DPO and EPObp were similar and higher than EPO. TSAT was most strongly correlated with ΔHb/EPO dose/kg in all three types of ESAs. Other significant independent factors were Hb, albumin, P, iPTH, and diabetic nephropathy in the EPO group, eGFR in the DPO group, and Fe in the EPObp group. The adjusted coefficient of determination ( R) ranged from 0.415 to 0.520 in the three ESA groups. Conclusions: The study results suggest that TSAT is the best predictor of the initial 12-week responsiveness to ESA, irrespective of the type. Variables not investigated in this study also affect responsiveness to ESA in Japanese pre-dialysis CKD patients. [ABSTRACT FROM AUTHOR]

Background: Limited prospective data are available on the long-term safety of darbepoetin alfa (DA) for treating anemia in children with chronic kidney disease (CKD). Methods: In this prospective, phase IV, observational registry study, children ≤16 years of age with CKD anemia and receiving DA were observed for ≤2 years. Adverse events (AEs), DA dosing, hemoglobin (Hb) concentrations, and transfusions were recorded. Results: A total of 319 patients were included in the analysis (mean age, 9.1 years), 158 (49.5 %) of whom were on dialysis at study entry. Of 434 serious AEs reported in 162 children, the most common were peritonitis (10.0 %), gastroenteritis (6.0 %), and hypertension (4.1 %). Six patients (1.9 %) died (unrelated to DA). Four patients (1.3 %) experienced six serious adverse drug reactions. The geometric mean DA dose range was 1.4-2.0 μg/kg/month. Mean baseline Hb concentration was 11.1 g/dl; mean values for children receiving and not receiving dialysis at baseline ranged between 10.9 and 11.5 g/dl and 11.2-11.7 g/dl, respectively. Overall, 48 patients (15.0 %) received ≥1 transfusion. Conclusions: No new safety signals for DA were identified in children receiving DA for CKD anemia for ≤2 years. Based on Hb concentrations and transfusion requirements, DA was effective at managing anemia in these patients. [ABSTRACT FROM AUTHOR]

Background: Anemia associated with high mortality is a common complication of chronic kidney disease (CKD). Target hemoglobin (Hb) levels for CKD treatment remain controversial: Recent guidelines recommend a maximum of 13 g/dL to avoid increased risk of CVD. However, some smaller studies show slower progression of renal function loss with high Hb targets. Recently, darbepoetin alfa targeting Hb 11-13 g/dL was reported to improve renal composite outcome of Japanese patients compared with a low Hb group maintained at 9.0-11.0 g/dL using epoetin alfa (HR 0.66; 95 % CI 0.47-0.93). The high Hb group showed significant reduction of left ventricular mass index and improved quality of life. Sub-analysis revealed greater beneficial effects in non-diabetic stage 5 CKD patients. This randomized controlled trial, PREDICT, aims to confirm the impact of targeting Hb levels of 11-13 g/dL using darbepoetin alfa with reference to a low Hb target of 9-11 g/dL. Methods: We calculated the number of subjects ( N = 440) necessary to detect a statistically significant level of α = 0.05 (two-sided) and statistical power of 80 % for a minimum follow-up period of 2 years on the basis of a previous study. Results: The study enrolled 498 non-diabetic Japanese patients with eGFR 8-20 mL/min/1.73 m. The primary outcome is a composite renal endpoint (starting chronic dialysis, transplantation, eGFR 6 mL/min/1.73 m or less, 50 % decrease in eGFR). Average follow-up period is 2 years and the study ends in 2016. Conclusion: PREDICT will determine the optimum target Hb for Japanese patients with non-diabetic CKD. (ClinicalTrials.gov No. NCT01581073). [ABSTRACT FROM AUTHOR]

A combination of cultural medium and nourishment providing a high yield of target glycated forms of recombinant darbepoetin alfa produced by CHO cell culture was selected. The influence of different substances-precursors of glycans in glycosylation reactions-on the yield of highly sialylated forms of recombinant darbepoetin alfa was researched. It was shown that the use of 20 mM N-acetyl-D-mannosamine is the most effective for an increase in the concentration of highly sialylated forms of the protein in cultural fluid. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to determine the population pharmacokinetics of darbepoetin alfa in hypothermic neonates with hypoxic-ischemic encephalopathy treated with hypothermia.Methods: Neonates ≥36 weeks gestation and <12 h postpartum with moderate to severe hypoxic-ischemic encephalopathy who were undergoing hypothermia treatment were recruited in this randomized, multicenter, investigational, new drug pharmacokinetic study. Two intravenous darbepoetin alfa treatment groups were evaluated: 2 and 10 µg/kg. Serum erythropoietin concentrations were measured using an enzyme-linked immunosorbent assay. Monolix 4.3.1 was used to estimate darbepoetin alfa clearance and volume of distribution. Covariates tested included: birthweight, gestational age, postnatal age, postmenstrual age, sex, Sarnat score, and study site.Results: Darbepoetin alfa pharmacokinetics were well described by a one-compartment model with exponential error. Clearance and the volume of distribution were scaled by birthweight (centered on the mean) a priori. Additionally, gestational age (also centered on the mean) significantly affected darbepoetin alfa clearance. Clearance and volume of distribution were estimated as 0.0465 L/h (95% confidence interval 0.0392-0.0537) and 1.58 L (95% confidence interval 1.29-1.87), respectively.Conclusions: A one-compartment model successfully described the pharmacokinetics of darbepoetin alfa among hypothermic neonates treated for hypoxic-ischemic encephalopathy. Clearance decreased with increasing gestational age. [ABSTRACT FROM AUTHOR]

Darbepoetin alfa (DA) is a standard treatment for anemia in lower-risk MDS. However, to date there has been no comparative study to investigate the initial dosage. We, thus, conducted a randomized controlled trial to elucidate the optimal initial dosage of DA. International Prognostic Scoring System low or intermediate-1 risk MDS patients with hemoglobin levels ≤9.0 g/dL, serum erythropoietin levels ≤500 mIU/mL, and red blood cell transfusion dependency were enrolled. Patients were randomized to receive DA either at 60, 120, or 240 μg/week for 16 weeks followed by continuous administration with dose adjustment up to 48 weeks. Of 17, 18, and 15 patients in the 60, 120, and 240 μg DA groups included in the efficacy analysis, 64.7, 44.4, and 66.7 %, respectively, achieved the primary endpoint (major or minor erythroid response), while 17.6, 16.7, and 33.3 % achieved major erythroid responses in the initial 16-week period. No clinically significant safety concerns were identified. DA reduced the transfusion requirements effectively and safely in transfusion-dependent, lower-risk MDS patients. Given the highest achievement rate of the major erythroid response in the 240 μg group and the absence of dose-dependent adverse events, 240 μg weekly is the optimal initial dosage. [ABSTRACT FROM AUTHOR]

Genetic constructs were designed in order to optimize darbepoetin production in CHO cells. They are characterized by a higher level of structural optimization of the darbepoetin gene, a higher gene dose, and the selection of promoter elements that have never been used before for this purpose. A transient transfection of CHO cells by the obtained constructs was performed. It was shown that each of the variable factors in the constructs influenced darbepoetin gene expression. A construct containing a doubled dose of the darbepoetin synthetic gene with optimized codon composition under the control of the CMV-EF1α chimerical promoter was proved to be the most efficient. [ABSTRACT FROM AUTHOR]

A stable cell line that is based on CHO cells and produces 100 mg per liter of culture medium of recombinant darbepoetin alpha with a target glycosylated isoforms effective yield of about 30% has been selected. The expression product of the cell line was characterized and compared to the originator (Aranesp, Amgen). It was shown that the obtained preparation contained all isoforms characteristic of the originator. The created cell line can be used for the development of industrial cultivation and a purification scheme for recombinant darbepoetin alpha production. [ABSTRACT FROM AUTHOR]

Background: Darbepoetin alfa (DA) is beneficial for pediatric patients for its less injection frequency and greater maximum dose compared to recombinant human erythropoietin. Here, we evaluated pharmacokinetics of DA in Japanese pediatric patients with chronic kidney disease (CKD). Methods: CKD patients (2-18 years old, n = 8 each) received a single dose of body weight adjusted DA either intravenously or subcutaneously. Results: When administered intravenously, the area under the concentration-time curve from time zero to infinity (AUC), clearance (CL) and terminal half-life ( t) of DA were 263.7 ng · h/mL, 1.77 mL/h/kg and 26.25 h, respectively (mean). In patients under 12 years old, AUC, CL and t were 219.1 ng · h/mL, 2.19 mL/h/kg, 23.62 h, respectively. These values were mostly similar to those of Japanese adult CKD patients, though AUC tended to be lower and CL tended to be higher in the subjects under 12 years old. When administered subcutaneously, time to reach maximum concentration ( t) and maximum concentration ( C) were 24.47 h and 1.704 ng/mL, and AUC, apparent clearance (CL/F) and t were 141.1 ng · h/mL, 3.23 mL/h/kg and 46.73 h, respectively. In patients under 12 years old, t and C were 7.50 h and 2.053 ng/mL, and AUC, CL/F and t were 136.7 ng · h/mL, 3.29 mL/h/kg and 37.75 h, respectively, which was higher in C, faster in t and shorter t compared to adult CKD patients, while AUC was not obviously different. Conclusion: The pharmacokinetics of DA in pediatric CKD patients is not obviously different from those in adult. [ABSTRACT FROM AUTHOR]

Introduction: There is scant real-world information on switching treatment for anemia associated with chronic kidney disease (CKD) from methoxy polyethylene glycol-epoetin beta (PEG-Epo) to darbepoetin alfa (DA). TRANSFORM was a multi-center, observational study designed to describe the time course of hemoglobin (Hb) concentration (primary outcome measure) and other parameters of clinical management of anemia in European hemodialysis patients in clinical practice before and after a switch from PEG-Epo to DA. Methods: Eligible subjects were adult patients with CKD dialyzed at European dialysis centers for ≥26 weeks and treated with PEG-Epo for ≥14 weeks immediately prior to being switched to DA and no earlier than January 2011. Erythropoiesis-stimulating agent doses and Hb values were recorded for the 14-week pre-switch and 26-week post-switch periods. Results: Of the 1,027 eligible patients enrolled at 42 hemodialysis centers in 7 European countries, 785 were included in analyses. Mean (95% confidence interval [CI]) Hb was generally stable: 11.19 (11.11, 11.26), 11.48 (11.40, 11.57), and 11.29 (11.20, 11.37) g/dL at month −1 pre-switch and months 3 and 6 post-switch, respectively. The geometric mean (95% CI) PEG-Epo dose at month −1 was 27.4 (26.0, 28.8) µg/week; DA dose was 29.4 (27.9, 30.9), 23.3 (21.9, 24.9), and 25.6 (24.1, 27.1) µg/week at months 1, 4, and 6, respectively. The geometric mean (95% CI) dose ratio at switching was 1.06 (1.01, 1.11). When stratifying by dose-ratio categories <0.8, 0.8-1.2, and >1.2 at switching, mean DA dose and Hb converged within narrow ranges by month 6 post-switch: 23.9-27.0 µg/week and 11.1-11.5 g/dL, respectively. Hb excursions <10 g/dL were less frequent post-switch versus pre-switch. Conclusion: Mean Hb values remained within a narrow range following switching from PEG-Epo to DA in this population of hemodialysis patients. Time trends of mean Hb and DA dose indicate that physicians titrated DA doses post-switch, to attain Hb concentrations comparable to those attained pre-switch with PEG-Epo. Funding: Amgen (Europe) GmbH, Zug, Switzerland. [ABSTRACT FROM AUTHOR]

Background: Higher doses of erythropoiesis-stimulating agents (ESA) have been associated with an increased risk of adverse outcomes in adults with chronic kidney disease (CKD) and end-stage kidney disease (ESRD), but to our knowledge no trials have been performed in children. We examined the association between ESA dose and all-cause mortality in a prevalent pediatric dialysis population. Methods: Retrospective cohort study utilizing national data on all prevalent dialysis patients aged <18 years from the Centers for Medicare and Medicaid Services' 2005 ESRD Clinical Performance Measures (CPM) project, linked to 18-month mortality records from the United States Renal Data System. Multivariate Cox proportional hazards regression was performed to determine the risk of mortality by mean weekly ESA dose. Results: Eight-hundred and twenty-nine children were included in the analysis; 7 % died during follow-up. A higher proportion of patients receiving ESA doses in the highest category (erythropoietin ≥350 units/kg/week or darbepoetin ≥1.5 units/kg/week) died (50 % vs 28 %, p = 0.002), and also demonstrated a trend toward lower hemoglobin (11.0 vs 11.4 g/dL, p = 0.05). In multivariate analysis, patients receiving the highest dose of ESA demonstrated an increased risk of mortality (hazard ratio 3.37; p value <0.01). Conclusion: Higher ESA dose is independently associated with mortality in children on chronic dialysis. [ABSTRACT FROM AUTHOR]

Background: Erythropoiesis-stimulating agents (ESAs) are standard therapy for chronic kidney disease (CKD) patients with renal anemia. However, few studies have compared the effects of different ESAs on anemia in identical pre-dialysis CKD patients. Methods: Seventy-nine patients who switched from epoetin beta to darbepoetin alfa (Group 1), and 82 patients who switched from darbepoetin alfa to epoetin beta pegol (Group 2) were enrolled in this study. Clinical and laboratory parameters were assessed for 6 months before and after switching ESAs. The prevalence of adverse events, the dose conversion ratio of ESAs, and the frequency of ESA administration were also analyzed. Results: Analysis of variance showed that switching ESAs did not significantly change hemoglobin levels for the study duration in both groups (mean hemoglobin 10.3-10.5 g/dL in Group 1 and 10.4-10.7 g/dL in Group 2). Estimated glomerular filtration rate, blood pressure, transferrin saturation, ferritin, and albumin remained constant in both groups. The prevalence of adverse effects was quite low (0-3.8 %) during both 6-month study periods. The mean dose conversion ratio for epoetin beta:darbepoetin alfa was 163.7 units:1 μg and for darbepoetin alfa:epoetin beta pegol was 1.08 μg:1 μg. The intervals of ESA administration significantly differed (epoetin beta pegol > darbepoetin alfa > epoetin beta). Conclusions: Epoetin beta, darbepoetin alfa, and epoetin beta pegol are effective and well-tolerated agents for managing anemia in Japanese pre-dialysis CKD patients. The intervals of ESA administration to maintain a patient's target hemoglobin were longer in the order of epoetin beta pegol > darbepoetin alfa > epoetin beta. [ABSTRACT FROM AUTHOR]

Background: We evaluated the safety and efficacy of darbepoetin alfa (DA), an attractive alternative to recombinant human erythropoietin (rHuEPO) in managing renal anemia, in Japanese children with chronic kidney disease (CKD) on peritoneal dialysis (PD) and hemodialysis (HD), and not on dialysis (ND). Methods: A total of 31 pediatric CKD patients (13 PD, 2 HD, and 16 ND) were enrolled. DA was administered bi-weekly intravenously (IV) or subcutaneously (SC) for PD or ND patients, and weekly IV for HD patients for 24 weeks. The target Hb was defined as 11.0 to ≤13.0 g/dl. In patients receiving rHuEPO, the initial DA dose was calculated at 1 μg DA for 200 IU rHuEPO. The initial DA dose for naïve patients was determined by body weight, and intended not to exceed 0.5 μg/kg per administration. For some PD or ND patients, the dosing frequency was subsequently changed to once every 4 weeks. Results: Mean Hb values increased from 10.5 ± 1.1 to 11.1 ± 1.1 g/dl after 4 weeks of DA treatment. The target Hb was achieved in all patients, 64.5 % of whom maintained the value at completion of the study. Hb responses were similar between IV and SC. The dosing frequency was extended to once every 4 weeks in 37.9 % of PD or ND patients. Eighty-seven adverse events were noted in 27 (87.1 %) of 31 patients, none of which were associated with DA. Conclusion: These results suggest that IV or SC administration of DA is an effective and safe treatment for renal anemia in Japanese children with CKD. [ABSTRACT FROM AUTHOR]

Erythropoietin (EPO) is a glycoprotein that stimulates production of red blood cells. After the patents for recombinant EPO (epoetin) expired in 2007, biosimilar erythropoiesis-stimulating agents (ESAs) have become widely circulated in the black market. However, the heterogeneity of ESAs in the post-translational glycosylation hinders the identification of these compounds. In the present study, after cleaving N-linked glycans from tryptic peptides of ESAs with N-glycosidase F, we analyzed the resulting eight glycan-free peptides by liquid chromatography-electrospray ionization-tandem mass spectrometry in the multiple reaction monitoring mode. It has been confirmed that all ESAs studied gave rise to common signature peptides SLTTLLR, VYSNFLR, and YLLEAK. In darbepoetin alfa (DPO), glycan-free tryptic peptide GQALLVNSSQVNETLQLHVDK was detected instead of GQALLVNSSQPWEPLQLHVDK in the epoetin. One of the signature peptides VNFYAWK was found to be significantly suppressed in continuous erythropoietin receptor activator (CERA), indicating pegylation at Lys52. Our method allowed simultaneous identification of ESAs including epoetin, DPO, CERA, and the biosimilars. [ABSTRACT FROM AUTHOR]

Background and Objectives: GC1113, a hybrid Fc-fused erythropoietin, is a novel erythropoiesis-stimulating agent that is expected to have an extended duration of action. The preclinical data showed that the hemoglobin increase lasted longer following GC1113 administration than it did following the administration of darbepoetin alfa (NESP). This study aimed to investigate the pharmacodynamic and pharmacokinetic characteristics and tolerability profiles of GC1113 in humans after single intravenous or subcutaneous administration and to compare the results with those for darbepoetin alfa. Methods: A dose-block randomized, placebo- and active-controlled, dose-escalation phase I clinical trial was conducted in 96 healthy volunteers. Blood samples were collected before and up to 672 h after drug administration and the serum erythropoietin concentration following the GC1113 or darbepoetin alfa administration was measured by an ELISA. The reticulocyte counts were measured for pharmacodynamic assessments. Pharmacokinetic and pharmacodynamic parameters were determined using non-compartmental methods. Results: The reticulocyte count-time profiles in the intravenous GC1113 3-5 μg/kg groups were comparable with those of the darbepoetin alfa 30 μg group. After subcutaneous administration of GC1113, reticulocyte count peaked later and decreased more slowly than it did following darbepoetin alfa administration. GC1113 (0.3-5 μg/kg intravenous, 1-8 μg/kg subcutaneous) was well-tolerated in the volunteers, and no immunogenicity was observed. Conclusion: GC1113 was tolerated and effective in the studied dose range; these findings could be applied to further clinical studies with patients. [ABSTRACT FROM AUTHOR]

Background: Darbepoetin alpha is a hypersialylated analogue of erythropoietin effective for activating erythropoietin-receptors. This study investigated the vasodilator and neuroprotective effects of darbepoetin alpha on an experimental subarachnoid hemorrhage model and compared it with erythropoietin. Methods: Forty adult male New Zealand white rabbits were randomly divided into four groups of ten rabbits each: group 1 (control), group 2 (subarachnoid hemorrhage), group 3 (erythropoietin), and group 4 (darbepoetin alpha). Recombinant human erythropoietin was administered at a dose of 1,000 U/kg intraperitoneally after the induction of subarachnoid hemorrhage and continued every 8 h up to 72 h. Darbepoetin alpha was administered at a single intraperitoneal dose of 30 μg/kg. Animals were killed 72 h after subarachnoid hemorrhage. Basilar artery cross-sectional areas, arterial wall thicknesses, hippocampal degeneration scores and biochemical analyses were measured in all groups. Results: Both erythropoietin and darbepoetin alpha treatments were found to attenuate cerebral vasospasm and provide neuroprotection after subarachnoid hemorrhage in rabbits. Darbepoetin alpha revealed better morphometric and histopathological results than erythropoietin among experimental subarachnoid hemorrhage-induced vasospasm. Conclusions: Our findings, for the first time, showed that darbepoetin alpha can prevent vasospasm and provides neuroprotection following experimental subarachnoid hemorrhage. Moreover, darbepoetin alpha showed better results when compared with erythropoietin. [ABSTRACT FROM AUTHOR]

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The misuse of recombinant human erythropoietin (rhEPO) increases the proliferation/production of erythrocytes, which enhance oxygen transport capacities, and has grave consequences with respect to human health and fairness in sports. For sports drug testing, the current analytical methods for rhEPOs are mainly gel electrophoretic methods, such as isoelectric focusing-polyacrylamide gel electrophoresis. Mass spectrometry is fundamentally necessary for the reliable identification of rhEPOs in doping control. In this study, a high-sensitivity and high-throughput mass spectrometric qualitative detection method for darbepoetin alfa in human urine was established by a bottom-up approach. The novel method involves the immunopurification of human urine (10 mL), protease digestion with endoproteinase Glu-C (V8-protease) in an ammonium bicarbonate buffer (pH 7.8) and ultra-performance liquid chromatography using a charged surface hybrid C column coupled with electrospray-ionisation high-sensitivity tandem mass spectrometry for improved selectivity of the target molecules. The specific fragment digested from darbepoetin alfa was TLQLHVDKAVSGLRSLTTLLRALGAQKE (V). The lower limit of detection of urinary darbepoetin alfa was 1.2 pg/mL. The limit of detection for the confirmation analysis was estimated to be 5 pg/mL. The developed method allows high-throughput confirmation analysis, namely 6 h for sample preparation and an analytical run time of only 10 min per sample; this high-throughput method dramatically decreases the workload in the laboratory. Darbepoetin alfa could be identified in human urine collected after the intravenous administration of 15 μg darbepoetin alfa ( n = 3). This mass spectrometric method is an innovative and powerful tool for detecting darbepoetin alfa in human urine for doping control testing. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Purpose: The erythropoiesis-stimulating agents (ESAs), darbepoetin alfa (DA), and epoetin alfa (EA) differ with respect to dosing schedule in chemotherapy-induced anemia. DA can be administered less frequently than EA, which may increase synchronicity between chemotherapy and ESA schedules. This study compared DA and EA with respect to frequency of synchronization and frequencies of total and ESA healthcare visits in current clinical practice. Methods: A retrospective analysis of ESA utilization during ESA episodes of care was conducted on all cancer patients identified in the SDI health oncology electronic medical records database who underwent chemotherapy and received ESA therapy from July 1, 2007 to March 31, 2010 ( n = 6522 DA, n = 3,439 EA). Results: The frequency of synchronization (chemotherapy and ESA therapy on the same day) was higher with DA (67 %) than EA (58 %) ( p < 0.001). The odds that an ESA administration was synchronized with chemotherapy were higher with DA compared with EA (odds ratio = 1.46, 95 % CI: 1.37, 1.54). Compared with EA, DA patients had 2.3 fewer visits with an ESA administration ( p < 0.001) and 3.0 fewer total visits ( p < 0.001). Conclusions: Compared with patients receiving EA, DA patients were more likely to have an ESA administration on the same healthcare visit as chemotherapy and had fewer visits for any cause or for ESA administration. These results suggest that through greater synchronization of ESA and chemotherapy administrations, DA may reduce patient and practice burden and healthcare utilization. [ABSTRACT FROM AUTHOR]

Introduction: There is limited information published on switching erythropoiesis-stimulating agent (ESA) treatment for anemia associated with chronic kidney disease (CKD) from darbepoetin alfa (DA) to methoxy polyethylene glycol-epoetin beta (PEG-Epo) outside the protocol of interventional clinical studies. AFFIRM (Aranesp Efficiency Relative to Mircera) was a retrospective, multi-site, observational study designed to estimate the population mean maintenance dose conversion ratio [DCR; dose ratio achieving comparable hemoglobin level (Hb) between two evaluation periods] in European hemodialysis patients whose treatment was switched from DA to PEG-Epo. Methods: Eligible patients had received hemodialysis for ≥12 months and DA for ≥7 months. Data were collected from 7 months before until 7 months after switching treatment. DCR was calculated for patients with Hb and ESA data available in both evaluation periods (EP; Months 1 and 2 were defined as the pre-switch EP, and Months 6 and 7 as the post-switch EP). Red blood cell transfusions pre- and post-switch were quantified. Results: Of 302 patients enrolled, 206 had data available for DCR analysis. The geometric mean DCR was 1.17 (95% CI 1.05, 1.29). Regression analysis indicated a non-linear relationship between pre- and post-switch ESA doses; DCR decreased with increasing pre-switch DA dose. The geometric mean weekly ESA doses were 24.1 μg DA in the pre-switch EP and 28.6 μg PEG-Epo in the post-switch EP. Mean Hb was 11.5 g/dL in the pre-switch EP and 11.4 g/dL in the post-switch EP. There were 16 transfusions and 34 units transfused in the pre-switch period, versus 48 transfusions and 95 units transfused post-switch. Excluding patients receiving a transfusion within 90 days of or during either EP, the DCR was 1.21 (95% CI 1.09, 1.35). Conclusion: In these hemodialysis patients switched from DA to PEG-Epo the DCR was 1.17 and 1.21 after accounting for the effect of transfusions. The number of transfusions and units transfused increased approximately threefold from the pre-switch to the post-switch period. [ABSTRACT FROM AUTHOR]

Minimal objective evidence exists regarding management of Friedreich's ataxia (FRDA). Antioxidant and recombinant human erythropoietin therapies have been considered potential treatments to slow progression of FRDA in a small number of studies. The primary objective of the current study was to test the efficacy, safety, and tolerability of triple therapy-darbepoetin alfa, idebenone, and riboflavin-in FRDA in a clinical pilot study. Patients included in this study were nine females, 16 to 45 years of age (average 28 ± 8), diagnosed with FRDA with confirmed GAA repeat expansion mutations in the FXN gene and a GAA repeat ≥400 on the shorter allele. Patients had a baseline score between 8 and 28.5 (average 20.7 ± 8.3) on the scale for the assessment and rating of ataxia and 94.3 ± 27.2 g/m in left ventricular mass index (LVMI). Patients had been treated with triple therapy with 150 μg darbepoetin alfa every 2 or 3 weeks, 10-20 mg/kg/day idebenone, and 10-15 mg/kg/day riboflavin for 32 ± 19.4 months (range of 8-56 months). Triple therapy was tolerated. Although not statistically significant, improvement of ataxia was observed during the first six 4-month periods of the study. Furthermore, a small decrease in disease progression during the first 2 years of treatment was observed. Long-term statistically nonsignificant improvement of LVMI and stability of the echocardiographic parameters could be considered. Triple therapy may slow disease progression of FRDA. [ABSTRACT FROM AUTHOR]

Background: The development of erythropoiesis-stimulating agents (ESAs) with extended serum half-lives has allowed marked prolongation of the administration intervals. The level of oxidative stress is increased in chronic kidney disease, and is reportedly decreased after long-term ESA treatment. However, the effect of different dosing regimens of ESAs on oxidative stress has not been elucidated. Methods: Five-sixths nephrectomized (NX) rats received either 0.4 μg/kg darbepoetin alfa (DA) weekly or 0.8 μg/kg DA fortnightly between weeks 4 and 10. NX animals receiving saline and a sham-operated (SHAM) group served as controls. The levels of oxidized and reduced glutathione (GSSG, GSH) were followed from blood samples drawn fortnightly. Results: During the follow-up, the ratios GSSG/GSH showed similar trends in both DA groups, levels being significantly lower than those in the SHAM group at weeks 8 and 10. GSSG levels were lower than the baseline throughout the study in all groups except for NX controls. The GSH levels were increased in all three NX groups (weeks 6-10) compared with both the baseline and the SHAM group Conclusion: Our results suggest that the extent of oxidative stress is similar in response to different dosing regimens of DA in 5/6 NX rats when comparable hemoglobin levels are maintained. These findings remain to be confirmed in chronic kidney disease patients. [ABSTRACT FROM AUTHOR]

Background: Darbepoetin alfa (DA) is an attractive alternative to recombinant human erythropoietin (rHuEPO) in managing renal anemia. Since DA has not been approved by the appropriate Japanese drug regulatory agencies for the indication of renal anemia in children in Japan, we have conducted a multicenter prospective study to determine the efficacy and safety of DA in Japanese children undergoing peritoneal dialysis (PD). Methods: Pediatric patients subcutaneously receiving rHuEPO were switched to DA treatment for a period of 28 weeks. The conversion to the initial dose of DA was calculated as 1 μg DA for 200 IU rHuEPO, and DA was administered intravenously once every 2 weeks. The target hemoglobin (Hb) concentration was defined as 11.0 to ≤13.0 g/dL. In some patients, the dose of DA was adjusted appropriately to achieve this target level, and/or the dosing frequency changed to once every 4 weeks. Results: In the 25 patients switched from rHuEPO to DA the mean Hb concentration increased from 9.9 ± 1.0 to 11.1 ± 1.0 g/dL at 8 weeks following commencement of the DA treatment. The target Hb concentration was achieved in 88 % of these patients, and 60 % maintained this target value on completion of the study. The dosing frequency was extended to once every 4 weeks in 60 % of patients. Twenty-four adverse events were noted in 11 of 25 patients (44 %); however, there was no causality between DA and adverse events. Conclusions: The results of this study suggest that intravenous administration of DA once every 2 or 4 weeks is an effective and safe treatment for renal anemia in Japanese children undergoing PD. [ABSTRACT FROM AUTHOR]

Background: The present study aimed to provide updated data on anaemia prevalence and management in cancer patients undergoing systemic therapy in Spain. Methods: This was a multicenter, observational, cross-sectional study performed in 2008. Eligible patients were ≥18 years, with non-myeloid malignancies treated with systemic therapy [chemotherapy (CT), hormonal therapy or immunotherapy]. Anaemia was defined according to WHO as haemoglobin (Hb) < 12 g/dL. Results: The study included 214 patients with a median age of 63 years (range 20-91), 58 % women, 73 % with solid tumours, and 79 % with advanced disease. CT was used in 91 % of patients (26 % with platinum compounds), hormonal therapy in 8.5 %, and immunotherapy in 8.5 %. In our study, 48.1 % of patients [95 % confidence interval (CI) 45.2-58.6] showed anaemia (31 % symptomatic): 42.0 % mild (10 ≤ Hb ≤ 11.9 g/dL), 5.6 % moderate (8 ≤ Hb ≤ 9.9 g/dL), and 0.5 % severe (Hb < 8 g/dL). A higher prevalence was observed in patients treated with CT (51 vs. 20 %, p = 0.01), platinum-based CT (70 vs. 47 %, p = 0.01) or palliative CT (61 vs. 39 %, p = 0.003). Anaemia was also more frequent in patients with more than three lines of CT (83 %) and in the fourth or subsequent CT cycle (58 %). Management in the previous 4 weeks in patients with anaemia was: 62 % did not receive treatment (92 % mild), 24 % received erythropoiesis-stimulating agents (ESAs), 14 % received iron and 8.7 % received transfusion. Conclusions: In Spanish hospitals, about half of patients with non-myeloid malignancies undergoing systemic therapy fulfilled anaemia criteria (87 % mild). Approximately two-third of patients with anaemia do not receive specific treatment and ESA use is below current guidelines. [ABSTRACT FROM AUTHOR]

Darbepoetin (DAR), with or without granulocyte colony-stimulating factor (G-CSF), has proved effective in treating anemia in patients with lower-risk myelodysplastic syndrome (MDS), but its effects on quality of life (QoL) and exercise functioning are less well established. In this phase II study (no. NCT00443339), lower-risk MDS patients with anemia and endogenous erythropoietin (EPO) level <500 IU/L received DAR 500 μg once every 2 weeks for 12 weeks, with G-CSF added at week 12 in non-responders. Physical performance was assessed with the 6-min walking test and, for fit patients, maximal oxygen consumption (VO). QoL was evaluated using SF-36 and FACT-An tests. In 99 patients, erythroid response rate according to IWG 2006 criteria was 48 and 56 % at 12 and 24 weeks, respectively. Addition of G-CSF rescued 22 % of non-responders. In 48 % of the responders, interval between darbepoetin injections could be increased for maintenance treatment. Serum EPO level was the only independent predictive factor of response at 12 weeks, and its most discriminant cutoff value was 100 IU/L. QoL and VO showed improvement over time in responders, compared with non-responders. With a median follow-up of 52 months, median response duration was not reached, and 3-year cumulative incidence of acute myeloid leukemia and overall survival (OS) was 14.5 and 70 %, respectively. Baseline transfusion dependence, International Prognostic Score System (IPSS), and Revised IPSS accurately predicted OS from treatment onset. Tolerance of darbepoetin was good. In conclusion, this regimen of darbepoetin every 2 weeks yielded high response rates and prolonged response duration. Objective improvement in exercise testing and in patient-reported QoL confirms the clinical relevance of anemia correction with erythropoiesis-stimulating agents. [ABSTRACT FROM AUTHOR]

Aims: There are concerns that biosimilar erythropoiesis-stimulating agents (ESAs) are less effective than the originator ESAs. The objective of our study was to investigate differences between originator and biosimilar ESA utilisation based on defined daily doses (DDD), doses upon switching, differences between short- and long-acting ESAs and prescribed daily doses (PDD) of either ESA in ambulatory patients with renal anaemia undergoing chronic maintenance haemodialysis [chronic kidney disease (CKD) stage 5]. Methods: Patients with CKD stage 5 and specific pharmacotherapy with ESAs for at least six 3-month periods (accounting quarters) were selected from a population-based database of accounting information of Bavarian physicians and pharmacy claims data (January 2008 to December 2010). The DDD was used to determine mean ESA consumption. Descriptive statistics were used to describe the results. Results: In our study, 6,177 CKD stage 5 patients received ESAs for ≥6 accounting quarters, of whom 64.4 % received originator ESAs, 21.1 % received biosimilars and 14.6 % received any sequence originator and biosimilar (total of 35.7 % any biosimilar). Patients receiving either originator short-acting ESAs, long-acting darbepoetin-alfa or M-PEG epoetin-beta had a median DDD consumption of 0.77, 0.81 and 0.90, respectively. Patients receiving a biosimilar short-acting ESA had a median DDD consumption of 0.82. Doses were not increased when the therapy was switched from the originator to the biosimilar ESA. These results were confirmed in 1,886 patients receiving a continuous prescription over 12 accounting quarters, with patients receiving short-acting originator ESAs, long-acting darbepoetin-alfa and biosimilar ESAs having a median daily DDD consumption of 0.80, 0.86 and 0.81, respectively. Conclusions: We conclude that, based on a population based analysis, ESA consumption of patients on chronic haemodialysis is similar for biosimilar and originator ESAs. [ABSTRACT FROM AUTHOR]

Background: Descending aortic (DA) surgery poses a high risk for spinal and cerebral infarction and routine use of lumbar drains allows for measurement of CSF markers of neurologic injury. Erythropoiesis medications have extensive preclinical data demonstrating neuroprotection. We hypothesized that prophylactic darbepoetin alfa (DARB) given before surgery reduces neurologic injury in patients undergoing DA repair. Methods and Results: We performed a prospective adaptive dose-finding trial of prophylactic DARB ( NCT00647998) that terminated prematurely following publication of an erythropoietin stroke study showing possible harm. Enrollment halted before dose adjustments; nine patients each received 1 mg/kg IV DARB immediately before surgery. A prospective cohort of nine untreated patients was subsequently obtained for comparison. The primary outcome of death or neurologic impairment at discharge occurred in 1/9 (11 %) DARB patients and 3/9 (33 %) controls ( p = 0.58). There were no statistical differences in changes of CSF biomarkers from baseline to 48 h comparing DARB patients to controls: S100β, median 214 versus 260 ng/ml ( p = 0.69); glial fibrillary acidic protein (GFAP), median 0.022 versus 0.58 ng/ml ( p = 0.45). In patients with early perioperative neurologic ischemia, there were greater changes in CSF biomarkers, compared to those without ischemia: S100β, median 2301 versus 124 ng/ml ( p = 0.04); GFAP, median 31.78 versus 0.31 ng/ml ( p = 0.34). Conclusions: There were no significant effects of prophylactic DARB on clinical outcome or CSF markers of neurologic injury in this pilot study, although all point estimates favored treatment. DA repair is a promising model of prophylactic neuroprotection. [ABSTRACT FROM AUTHOR]

Purpose: Erythropoiesis-stimulating agents can reduce red blood cell transfusion rates in patients developing anemia while receiving chemotherapy. We investigated potential cost savings from reduced transfusion rates in patients starting darbepoetin alfa (DA) at higher versus lower hemoglobin (Hb) levels. Methods: Two systematic literature reviews were performed: transfusion outcomes in patients receiving DA stratified by baseline Hb level and costs of transfusion in Europe. Potential cost savings were calculated by multiplying the difference in transfusion rates between Hb levels by the midpoint of transfusion costs. Results: Despite differences in baseline characteristics, treatment duration and analysis technique, the clinical studies ( n = 8) showed that fewer transfusions were required when DA was initiated at higher versus lower Hb levels. The economic studies ( n = 9) showed that 1 unit of transfusion ranged from €130 to €537 (2010-adjusted values). Cost savings from initiating DA at higher versus lower Hb levels were €503-2,226 (2 units transfused) and €880-3,895 (3.5 units) per ten patients. Conclusions: Transfusion incidence increases with DA initiation at lower Hb levels. Potential cost savings depend on the number of units transfused and cost items included. DA initiation according to guidelines can reduce transfusions and potentially reduce transfusion-associated costs. [ABSTRACT FROM AUTHOR]

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Darbepoetin alfa (DA) is an erythropoiesis-stimulating agent (ESA) approved for treating chemotherapy-induced anemia (CIA). Safety concerns have prompted changes to the ESA-product information, which now recommends initiating ESAs at hemoglobin (Hb) levels <10 g/dL (US) or ≤10 g/dL (EU). The present exploratory analysis of a DA trial examined how baseline-Hb levels at ESA initiation affect transfusion rates, Hb response, and safety outcomes in CIA patients. Data were retrospectively analyzed from a phase 3 trial of CIA patients randomised to 500 mcg DA every 3 weeks (Q3 W) or to 2.25 mcg/kg DA weekly (QW) for 15 weeks. In the current analysis, data were reanalyzed by baseline-Hb categories of <9 g/dL ( n = 126), 9 to <10 g/dL ( n = 225), and ≥10 g/dL ( n = 354). The Q3 W and QW groups were combined. Transfusion rates were highest in the <9 g/dL baseline-Hb group in all time periods examined. The Kaplan-Meier percentage (95% CI) of patients achieving Hb ≥10 g/dL was 68% (59, 78) and 88% (82, 92) in the <9 g/dL and 9 to <10 g/dL baseline-Hb groups, respectively. With lower baseline-Hb, incidence of a ≥1 g/dL-Hb rise in 14 days progressively decreased. Incidence of venous thromboembolic events was similar in all baseline-Hb groups and similar between patients with or without a ≥1 g/dL-Hb rise in 14 days. Overall, transfusion risk increased and Hb response decreased at lower baseline-Hb levels in this exploratory analysis. When following ESA-product information to initiate ESAs at Hb ≤ 10 g/dL, the greatest benefit may be achieved when initiating close to 10 g/dL. Prospective studies are needed to further examine this hypothesis. [ABSTRACT FROM AUTHOR]

Background: Darbepoetin-alpha (DA) is a novel erythropoiesis-stimulating agent developed for treating anemia. In animal models, recombinant human erythropoietin has been reported to be beneficial for neuroprotection. In this study, we determined whether DA would protect the spinal cord against ischemia-reperfusion injury in a rabbit model. Methods: Forty rabbits were randomized into five groups of eight animals each: group 1 (sham), group 2 (ischemia), group 3 (vehicle), group 4 (30 mg/kg methylprednisolone), group 5 (30 μg/kg DA). Only laparotomy was performed in the sham group. In all the other groups, the spinal cord ischemia model was created by a 20-min occlusion of the aorta just caudal to renal artery with an aneurysm clip. The drugs were administered immediately after the clamp was removed. The animals were killed 24 h later. Spinal cord segments between L2 and L5 were harvested for analysis. Neurological evaluation was performed with the Tarlov scoring system just before the animals were killed. Level of tissue malondialdehyde was analyzed as a marker of lipid peroxidation and tissue caspase-3 activity as a marker of apoptosis. Also, histopathological evaluation of the tissues was performed. Results: Both malondialdehyde and caspase-3 levels were significantly decreased by DA administration. Histopathological evaluation of the tissues also demonstrated decrease in neuronal degeneration and infiltration parameters after DA administration. In the DA group, neurological outcome scores were statistically significantly better compared with the ischemia and the vehicle groups. Conclusions: Although further studies considering different dose regimens and time intervals are required, DA was shown to be at least as effective as methylprednisolone in spinal cord ischemia/reperfusion model. [ABSTRACT FROM AUTHOR]

Purpose: This analysis examined the effects of darbepoetin alfa on hemoglobin and fatigue outcomes in patients with cancer using latent growth curve modeling (LGM). Methods: Data from 4 clinical trials of darbepoetin alfa in lung cancer (2 studies; n = 547; n = 288), lymphoproliferative malignancies ( n = 339), and non-myeloid malignancies ( n = 320) were analyzed separately. Fatigue was assessed using the FACT-Fatigue (FACT-F) scale. Effects of darbepoetin alfa on changes in hemoglobin and FACT-F scores were evaluated using LGM, controlling for age, gender, Eastern Cooperative Oncology Group performance status, health status, and total transfusions. Results: Patients receiving darbepoetin alfa had higher rates of change in hemoglobin (standardized regression coefficient [ $$ \hat{\beta } $$] = 0.30 to 0.53, all P < 0.05) than placebo. Patients with greater rates of change in hemoglobin reported improvements in fatigue outcomes ( $$ \hat{\beta } $$ = 0.28 to 0.59, all P < 0.05). The total standardized effect of darbepoetin alfa on fatigue outcomes corresponded to a mean change of 0.9 to 3.5 points in FACT-F scores, with one trial demonstrating changes exceeding the minimal important difference of 3 points. Conclusions: Darbepoetin alfa improved hemoglobin which was associated with improved fatigue across the 4 trials. Clinically, meaningful improvement in fatigue was seen in 2 trials. More complex statistical analysis models of treatment may assist in understanding the effects of erythropoiesis-stimulating agents on patient-reported outcomes. [ABSTRACT FROM AUTHOR]