Anemia treatment with Q2W darbepoetin alfa in patients with chronic kidney disease naïve to erythropoiesis-stimulating agents*

ABSTRACT

Objective: To evaluate the efficacy and safety of darbepoetin alfa dosed every-other-week (Q2W) to treat anemia in subjects with chronic kidney disease (CKD), not receiving dialysis, who were naïve to erythropoiesis-stimulating agent (ESA) therapy.

Research design and methods: This was an open-label, multicenter, single-arm study enrolling ESA-naïve CKD subjects with baseline hemoglobin (Hb)?<?11.0?g/dL. Q2W darbepoetin alfa treatment was initiated at a dose of 0.75?µg/kg and titrated to achieve and maintain Hb levels at 11.0–13.0?g/dL. Treatment was administered from week 1 to week 19.

Main outcome measures: The primary endpoint was the proportion of subjects who achieved Hb?≥?11?g/dL at any study visit, except in week 1. Hb levels, darbepoetin alfa dose, and safety were also assessed.

Results: Of the 128 subjects who received at least one dose of darbepoetin alfa and of the subjects who completed the study, 118 (92%) and 112 (97%), respectively, achieved a Hb?≥?11?g/dL in a median time of 5 weeks. Median darbepoetin alfa dose at week 1 and at the time of achieving a Hb?≥?11?g/dL were 60 and 80?µg, respectively. Darbepoetin alfa was well-tolerated, and short-term adverse events were consistent with those expected in CKD subjects.

Conclusions: This study demonstrates that de novo Q2W darbepoetin alfa was effective in correcting and maintaining Hb levels in ESA-naïve subjects with CKD who were not receiving dialysis. Study limitations, including lack of a control arm for the study and multiple race information for subjects, must be considered in interpreting the results.

Trial registration: ClinicalTrials.gov identifier: NCT00112008.     

Randomized,double-blind,placebo-controlled trial of every-3-week darbepoetin alfa 300 micrograms for treatment of chemotherapy-induced anemia

ABSTRACT

Objective: Darbepoetin alfa is effective in treating chemotherapy-induced anemia (CIA). Administration of subcutaneous darbepoetin alfa every 3 weeks (Q3W) could simplify treatment through synchronization with common Q3W chemotherapy regimens. We report results from a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial evaluating the efficacy and safety of fixed-dose Q3W darbepoetin alfa in patients with a wide variety of tumor types who experienced CIA.

Research design and methods: Patients aged?≥?18 years with anemia (hemoglobin <11?g/dL) being treated for nonmyeloid malignancy were randomized 1:1 to receive darbepoetin alfa 300?μg (n?=?193) or placebo (n?=?193) subcutaneously Q3W from weeks 1 to 13 in this 16-week study. Doses could be adjusted per prespecified rules.

Main outcome measures: The primary endpoint was the proportion of patients who received ≥1 red blood cell (RBC) transfusion between week 5 and the end of the treatment period (EOTP). The study also analyzed the proportions of patients achieving a hemoglobin concentration ≥11?g/dL and subsequently maintaining hemoglobin levels above 11?g/dL, and the change in hemoglobin concentration over time.

Results: The proportion of patients requiring RBC transfusions between week 5 and EOTP was significantly lower in the darbepoetin alfa-treated group than in the placebo-treated group (24 vs. 41% of patients, a 16.3% difference, p?<?0.001). There were no differences between the two treatment arms in quality-of-life measures. Cardiovascular/thromboembolic adverse events were uncommon and were not associated with increases in hemoglobin levels. Study limitations suggest caution in the interpretation of these results: transfusions, the primary endpoint, were recommended but not required if hemoglobin concentrations were ≤8.0?g/dL, and protocol deviations (primarily dosing errors) occurred in approximately one-half of the patients in both treatment groups.

Conclusions: In this study, fixed-dose Q3W darbepoetin alfa appeared to be well-tolerated and effective for the treatment of CIA.

Trial registration: ClinicalTrials.gov identifier: NCT00110955.     

A randomised,cross-over study comparing injection site pain with subcutaneous epoetin beta and subcutaneous darbepoetin alfa in patients with chronic kidney disease*

ABSTRACT

Objective: To compare injection site pain of subcutaneous (sc) epoetin beta and darbepoetin alfa in adult patients with chronic kidney disease.

Research design and methods: This was a multi-centre, randomised, two-arm, single-blind, cross-over study. Patients were randomised to receive weekly sc darbepoetin alfa 30?μg or weekly sc epoetin beta 6000?IU for 2 weeks and were then crossed over to the alternative treatment for 2 weeks. Injection site pain was assessed using a 10?cm ungraduated visual analogue scale (0?=?no pain, 10?=?worst pain) and a six-point verbal rating scale. Patient preference for treatment was also assessed.

Trial registration: http://clinicaltrials.gov/(NCT00377481).

Results: All randomised patients (N?=?48) completed the study. The sample comprised 29 chronic kidney disease patients (Stage 3 or Stage 4), 11 peritoneal dialysis patients and 8 renal transplant patients. Patients perceived significantly less pain with epoetin beta than darbepoetin alfa, using the visual analogue scale (relative pain score?=?2.75, darbepoetin alfa:epoetin beta, 95% CI: 1.85, 4.07; p?<?0.0001) and the verbal rating scale (median: 0.5, 95% CI: 0.5, 1.0 vs. median: 1.5, 95% CI: 1.0, 2.0; p?<?0.0001). Epoetin beta was preferred by significantly more patients (65%) than darbepoetin alfa (10%) (p?<?0.001); 25% of patients reported no preference.

Conclusions: Limitations included lack of an epoetin alfa comparator and limited blinding (patients were blinded to treatment, however, an unblinded nurse administered treatment). We show that sc injection of epoetin beta is significantly less painful than darbepoetin alfa and patient preference for epoetin beta confirms that the difference is clinically meaningful.     

The association of darbepoetin alfa with hemoglobin and health-related quality of life in patients with chronic kidney disease not receiving dialysis

ABSTRACT

Objective: Anemia of chronic kidney disease (CKD) decreases patients’ health-related quality of life (HRQoL). The objective of this subanalysis was to determine the effect of every-other-week (Q2W) darbepoetin alfa on hemoglobin (Hb) levels and HRQoL measures in subjects with CKD who are naïve to erythropoiesis-stimulating agents (ESAs).

Methods: STAAR was a 52-week, multicenter, single-arm study. Subject inclusion criteria included: ≥?18?years of age and creatinine clearance ≤?70?mL/min or estimated glomerular filtration rate ≤?60?mL/min/1.73 m² but not receiving dialysis. Subjects included in this subanalysis were previously naïve to ESAs, had Hb <?11?g/dL, were initiated on subcutaneous Q2W darbepoetin alfa to achieve a Hb level not to exceed 12?g/dL, and had responses to at least one question on the KDQOL-CRI forms administered at baseline, week 12, and week 52.

Results: Of 911 ESA-naïve subjects enrolled in the study, 277 (30.4%) were included in this subanalysis. The majority of subanalysis subjects were Caucasian (63.2%) and/or women (54.5%). Mean Hb concentrations and all KDQOL-CRI scores improved significantly between baseline and week 12 (?p < 0.0001), and were maintained until week 52. Darbepoetin alfa was well tolerated.

Conclusions: Darbepoetin alfa initiated Q2W achieved and maintained Hb targets, and significantly improved and maintained HRQoL in study subjects with CKD. Limitations of the study must be considered when extrapolating these results to assess the benefits of treatment on HRQoL in the general CKD population.     

Reengineering clinical operations in a medical practice to optimize the management of anemia of chronic kidney disease

OBJECTIVES: To describe the clinic design, clinical evaluations, and treatment approaches used in a multidisciplinary clinic for management of anemia of chronic kidney disease (CKD), and to evaluate several selected clinical outcomes associated with this approach to anemia management. SETTING: University-affiliated, division of nephrology, outpatient multidisciplinary model CKD clinic headed by a clinical pharmacist. PATIENTS: One hundred sixty-six patients with anemia of CKD who were referred by nephrologists and primary care providers to the multidisciplinary clinic from March 1, 2002-July 31, 2004. MEASUREMENTS AND MAIN RESULTS: Patients received darbepoetin alfa dosed on an every-other-week basis. If patients were already receiving once-weekly recombinant human erythropoietin (r-HuEPO), the darbepoetin alfa dose was calculated by using the darbepoetin alfa package insert conversion table. If patients were na?ve to previous erythropoietic therapy, the darbepoetin alfa dose was either 60 microg or 0.7 microg/kg. The dose and frequency of darbepoetin alfa and oral iron supplements were adjusted to achieve the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) targets for hemoglobin levels and iron measures. The primary outcome analyzed was the proportion of patients with at least 30 days of treatment who achieved a target hemoglobin level of 11.0 g/dl or greater. Of 128 patients who received at least 30 days of treatment, 100 (78%) attained the hemoglobin level (mean +/- SD 11.7 +/- 7 g/dl). Ninety-nine of 128 patients were originally na?ve to erythropoietic therapy; 77 (78%) of these 99 patients achieved the hemoglobin target in a mean +/- SD of 7.9 +/- 7.5 weeks. These data contrast with the data of 29 patients seen in the year previous to the reengineered clinic process, whereby only 12 (41%) of these comparable patients reached hemoglobin target with r-HuEPO therapy. Of the 77 previously erythropoietic-na?ve patients, 82% were receiving darbepoetin alfa every other week, 14% every 3 weeks, and 4% every 4 weeks at the time the hemoglobin target was achieved. Oral iron administration significantly increased the chance of achieving the K/DOQI targets for hemoglobin and iron. CONCLUSION: Redefining roles and practices of members of a clinical practice and reengineering processes for anemia management were effective in achieving and maintaining target hemoglobin and iron levels.     

Early hemoglobin response and alternative metrics of efficacy with erythropoietic agents for chemotherapy-related anemia

ABSTRACT

Objective: To examine associations between early hemoglobin response and alternative measures of efficacy following treatment with an erythropoietic agent for chemotherapy-related anemia.

Research design and methods: Preliminary data from an ongoing randomized, multicenter, 16‐week, open-label clinical trial of epoetin alfa versus darbepoetin alfa were used to dichotomize patients based on attainment of early hemoglobin response (≥ 1?g/dL increase in hemoglobin level within 4 weeks of treatment initiation). Measures of efficacy were compared between patients with early hemoglobin response and those without. Sensitivity analyses were then performed to evaluate the impact of various methods for handling censored data and hemoglobin values following blood transfusion.

Main outcome measures: Efficacy measures included: the proportion of patients with a ≥ 1?g/dL increase in hemoglobin by 4 weeks or a ≥ 2?g/dL increase by 8 weeks; mean hemoglobin levels at 4, 8, 12, and 16 weeks; area under the curve for change in hemoglobin level; proportion of patients who required a blood transfusion after 4 weeks; proportion of follow-up days on which patients had hemoglobin levels within the therapeutic range of 11?g/dL to 13?g/dL; and proportion of patients who never had a hemoglobin level within this range.

Results: A total of 274 patients were included (66.1% female, mean age 62.4), of whom 48.9% had an early hemoglobin response and 51.1% did not. Mean duration of follow-up was 10.1 ± 5.05 weeks. All metrics indicated superior longer-term response among patients with early hemoglobin response compared to patients without early response. The findings were robust across sensitivity analyses. Although the analysis establishes a significant relationship between early hemoglobin response and alternative efficacy metrics, causality cannot be inferred.

Conclusions: Early hemoglobin response is significantly associated with various metrics of clinical response to erythropoietic agents and is an appropriate measure for evaluating treatment effects.     

Comparison of the therapeutic effects of epoetin zeta to epoetin alfa in the maintenance phase of renal anaemia treatment

ABSTRACT

Objective: To evaluate the therapeutic efficacy and safety of epoetin zeta, compared with epoetin alfa, in maintaining target haemoglobin (Hb) concentrations in patients with anaemia and chronic kidney disease (CKD) maintained on haemodialysis.

Methods: Patients received epoetin zeta or epoetin alfa intravenously, 1–3 times/week for 12 weeks, then the alternative treatment for 12 weeks, in this double-blind, crossover, phase III trial. Eligible patients were 18–75 years old with CKD stage 5 maintained on haemodialysis. Patients had received epoetin for ≥ 3 months upon study entry and had achieved a target Hb level of 10.5–12.5?g/dL with a stable epoetin dose.

Main outcome measures: Primary efficacy endpoints were intra-individual differences (test–reference) in mean Hb levels and mean weekly dose/kg of body weight. Safety endpoints included occurrence of neutralizing anti-erythro­poietin antibodies, tolerability, and adverse events (AEs).

Results: In total, 313 patients were randomized to receive epoetin zeta (n = 155) or epoetin alfa (n = 158); 146 and 145 patients (respectively) switched treatment after 12 weeks. Mean (range) Hb levels were 11.35 (8.96–14.22) g/dL and 11.54 (8.74–13.84) g/dL for patients receiving epoetin zeta and epoetin alfa, respectively (95% confidence interval [CI] [test–reference]: 0.09–0.28?g/dL, within the predefined equivalence range of ±?0.6?g/dL). Mean (range) weekly doses were 92.68 (12.74–398.41) IU/kg/wk and 92.58 (10.53–393.07) IU/kg/wk for patients receiving epoetin zeta and epoetin alfa, respectively (95% CI [test–reference]: –4.67 and 4.29 IU/kg/wk, within the equivalence range of ±?45.00?IU/kg/wk). Patients underwent minor nominal dose adjustments during treatment crossover. AE profile was similar for both products; the most commonly reported AEs were infections and infestations (in 26.5% of patients receiving epoetin zeta and 23.6% receiving epoetin alfa). No patients developed neutralizing anti-erythropoietin antibodies.

Conclusions: Epoetin zeta is therapeutically equivalent to epoetin alfa in the maintenance of target Hb levels in patients with renal anaemia. No unexpected AEs were seen.     

Comparison of the therapeutic effects of epoetin zeta and epoetin alfa in the correction of renal anaemia

ABSTRACT

Objective: To assess the therapeutic equivalence of epoetin zeta and epoetin alfa for correction of haemoglobin (Hb) concentration in patients with anaemia and chronic kidney disease (CKD) stage 5 maintained on haemodialysis.

Study design: In total, 609 patients with CKD and anaemia (Hb?<?9?g/dL) were randomly assigned to receive either epoetin zeta or epoetin alfa intravenously, one to three times per week for 24 weeks. Dosing was titrated individually to achieve a stable, target Hb concentration of 11–12?g/dL. Primary endpoints were the mean weekly dose of epoetin per kilogram of body weight and mean Hb concentration during the last 4 weeks of treatment. Safety endpoints were the occurrence of anti-erythropoietin antibodies, ratings of tolerability and adverse events (AEs).

Results: Mean (± standard deviation [SD]) Hb concentration over the last 4 weeks of treatment was 11.61?±?1.27?g/dL for patients receiving epoetin zeta, compared with 11.63?±?1.37?g/dL for patients receiving epoetin alfa (95% confidence interval [CI]: –0.25 to 0.20?g/dL). Mean (± SD) epoetin zeta weekly dose over the last 4 weeks of treatment was 182.20?±?118.11?IU/kg/wk, compared with 166.14?±?109.85?IU/kg/wk for epoetin alfa (95% CI: –3.21 to 35.34?IU/kg/wk). The most commonly reported AEs (> 5% of patients) were infections and infestations (12.5% and 12.8% of patients treated with epoetin zeta and epoetin alfa, respectively) and vascular disorders (8.5% and 8.9%, respectively). No patients developed neutralizing anti-erythropoietin antibodies.

Conclusions: Epoetin zeta, administered intravenously, is therapeutically equivalent to epoetin alfa in the correction of low Hb concentration in patients with CKD undergoing haemodialysis. No unexpected AEs were seen and both epoetin zeta and epoetin alfa were well tolerated.     

Darbepoetin alfa: in patients with chemotherapy-related anaemia

Darbepoetin alfa, novel erythropoiesis stimulating protein closely related to human erythropoietin, has been developed for the treatment of chemotherapy-related anaemia in patients with non-myeloid malignancies. In three 12-week, phase II studies in patients with cancer and chemotherapy-related anaemia, subcutaneous darbepoetin alfa, administered in once-weekly or 2-, 3- or 4-weekly regimens, dose-dependently increased the mean haemoglobin levels. In a randomised, double-blind, phase III study in 320 patients with lung cancer and chemotherapy-related anaemia, recipients of subcutaneous darbepoetin alfa 2.25 micro g/kg once weekly, received red blood cell (RBC) transfusion approximate, equals 2-fold less frequently than placebo recipients (p < 0.001). In the same study, patients receiving darbepoetin alfa also received fewer standard units of RBC for transfusion and had greater haematopoietic response rate than placebo recipients (both p < 0.001). Subcutaneous darbepoetin alfa 2.25 micro g/kg once weekly also reduced patient-reported fatigue (assessed by a quality-of-life questionnaire) [p = 0.019 vs placebo]. black triangle Darbepoetin alfa was generally well tolerated in clinical trials. The most frequent darbepoetin alfa-related adverse events were: body oedema, arthralgia and skin rash.     

Association of anemia correction with health related quality of life in patients not on dialysis*

ABSTRACT

Objective: This was an open-label study to asses the association of changes in hemoglobin with changes in health related quality of life (HRQOL) in patients treated with darbepoetin alfa.

Methods: Originally, 81 chronic kidney disease (CKD) patients not on dialysis and naïve to erythropoiesis stimulating agents (ESA) were randomly assigned into two open-label groups (3?:?1). As a majority of control group patients opted out of control status, this study reports on the single arm study analysis that was performed on the 48 patients who received the drug through week 16. Sixty-two patients received once-weekly darbepoetin alfa in addition to conservative management for CKD. Instruments that measured general (SF‐36, FACT-anemia, FACT-fatigue, ADL and IADL) and disease specific (KDQOL) HRQOL domains were administered at baseline and after 8, 16, and 24 weeks.

Results: Compared to baseline values, mean HRQOL subscales were significantly improved in the treatment group at 16 weeks (?p < 0.05 for SF‐36 physical function; p < 0.001 for SF‐36 vitality, FACT anemia and FACT fatigue scales). At week 16, the SF‐36 mean increase for 48 treatment patients in the Vitality Subscale Score was 14.9 (SD 3.2) and the mean increase in the KDQOL Burden of Kidney Disease Subscale was 5.5 (SD 3.3). Multivariate regression analysis demonstrated a statistically significant association (?p < 0.05) between hemoglobin levels and higher HRQOL scores on several physical function, energy and fatigue scales.

Conclusion: Improvements in hemoglobin in CKD patients not on dialysis were associated with statistically significant (?p < 0.05), clinically meaningful (>?5 points) HRQOL improvements on scales measuring physical activity, vitality and fatigue. Our study did not show an association between increased hemoglobin levels and other aspects of HRQOL, such as those relating to emotional status, sexual activity or cognition. The interpretation of our results is limited by the lack of a control arm to assess whether conservative therapy for CKD, in the absence of ESA administration, would have a comparable effect on patients’ HRQOL scores. Further research needs to examine whether other aspects of HRQOL improve with anemia treatment, in the same way as those aspects of HRQOL more closely related to physical activity and fatigue.     

Use and cost of erythropoiesis-stimulating agents in patients with cancer

ABSTRACT

Objective: To compare the baseline characteristics, episodes of care, and cost of erythropoiesis-stimulating agents among cancer patients in a US managed-care population.

Research design and methods: Retrospective analysis of administrative claims data. Episodes of care for patients with cancer receiving erythropoiesis-stimulating agents between January 1, 2004 and January 17, 2006 included all claims for erythropoiesis-stimulating agents with ≤42 days’ gap between claims, plus the duration of therapeutic benefit based on median days between consecutive doses.

Main outcome measures: Main outcome measures were average weekly dose of erythropoiesis-stimulating agents and costs of therapy.

Results: A total of 15?007 eligible episodes of care (darbepoetin alfa, 7769 episodes [5587 patients]; epoetin alfa 7238 episodes [5157 patients]) were identified. Fewer claims were observed per episode of care for darbepoetin alfa than for epoetin alfa (mean [SD] 3.7 [4.1] vs. 5.3 [6.4]). The median time between consecutive claims was 15 days (darbepoetin alfa) and 8 days (epoetin alfa). The mean (SD) weekly doses were 105 (56)?μg (darbepoetin alfa) and 34?242 (28173) U (epoetin alfa), a dose-comparison ratio of 326?:?1.

Dose-comparison ratios were sensitive to assumptions about duration of clinical benefit.

The mean (95% CI) weekly costs were significantly lower for darbepoetin alfa ($560 [553–567]) than for epoetin alfa ($645 [630–659], p < 0.0001) when duration of clinical benefit was considered.

Conclusions: Significant differences characterize patterns of use of erythropoiesis-stimulating agents. Duration of therapeutic benefit is an important variable in comparing darbepoetin alfa with epoetin alfa; incorporation of this variable in analyses of costs of therapy may have notable effects on calculated treatment costs. Limitations of the study include the potential for database errors or omissions, lack of detailed disease data, and lack of adjustment for differences in the ages and comorbidities of patients.     

Every-three-week administration of darbepoetin alfa in women with chemotherapy-associated anemia.

PURPOSE: The effectiveness of every-three-week administration of darbepoetin alfa in women with chemotherapy-associated anemia was evaluated. METHODS: Women receiving chemotherapy for gynecological tumors who had a hemoglobin concentration of <10 g/dL were recruited from an obstetrics and gynecology service. Study patients received subcutaneous darbepoetin alfa 6.75 microg/kg, followed by 4.5 microg/kg every three weeks for a total of up to six doses. Hematopoietic response and mean changes in hemoglobin concentrations were evaluated. The Functional Assessment in Cancer Therapy-Anemia (FACT-An) survey was self-administered before and after study completion to evaluate the patients' quality of life. RESULTS: The mean+/-S.D. age and weight for the 14 patients recruited (12 of whom were assessable) were 52.1+/-14 years and 64.6+/-19.8 kg, respectively. The mean initial and maintenance doses were 442 and 301.6 microg, respectively. The overall hematopoietic response was 64.3%, of which 35.7% were complete and 28.6% were partial. Peak response occurred at weeks 9 and 12. The mean+/-S.D. change in hemoglobin concentration was 1.6+/-1.51 g/dL. Treatment failure was predicted by week 9 (n=2). Maintenance doses were withheld if a patient's hemoglobin concentration exceeded 12 g/dL (n=3). The mean+/-S.D. point differential for FACT-An pretreatment and posttreatment scores was 5.8+/-4.71 (n=6). CONCLUSION: Every-three-week administration of subcutaneous darbepoetin alfa produced a complete or partial hematopoietic response in 11 of 14 women with chemotherapy- associated anemia. A quality-of-life indicator generally improved among the 6 patients for whom posttreatment quality-of-life data were available.     

Improved Haemoglobin Concentrations with IV Darbepoetin alfa - Case Studies of Haemodialysis Patients

Summary

This paper presents two case histories of patients receiving intravenous (IV) darbepoetin alfa for the treatment of anaemia in chronic renal

failure. The paper sets these cases against the general clinical picture of patients receiving intravenous darbepoetin alfa in our renal unit.     

Achieving therapeutic targets in renal anaemia: considering cost-efficacy

SUMMARY

Erythropoietin treatment for anaemia in chronic kidney disease (CKD) brings important clinical benefits, but restricted healthcare budgets necessitate value-for-money therapies, requiring economic considerations also to be taken into account when selecting a treatment regimen. Subcutaneous (SC) administration of epoetin is effective at a lower dose than intravenous (IV) administration, offering the potential for substantial reductions in costs of treatment. Unlike epoetin alfa, which is contra-indicated by the SC route in Europe in patients with CKD, epoetin beta (NeoRecormon*) can be safely and effectively given by either route. The multidose presentations of epoetin beta (Reco-Pen?, multidose vials) may provide further opportunity for dose reduction. The tolerability of SC epoetin beta is excellent and superior compared with epoetin alfa or darbepoetin alfa. Epoetin beta given once weekly is as effective as two- or three-times weekly, and the dosing frequency can be further reduced to once every 2^?weeks in patients who are stable on once-weekly dosing. Reduced dosing frequency is more convenient for the patient and may save nursing time in dialysis units. Overall, SC epoetin beta, compared with alternative treatments, may represent a cost-effective treatment option for anaemia management as it combines a well-established safety and efficacy record, favourable local tolerability, and the convenience of once-weekly dosing with the potential to reduce treatment costs by up to 30%.     

Once-monthly administration of darbepoetin alfa for the treatment of patients with chronic heart failure and anemia: a pharmacokinetic and pharmacodynamic investigation

In patients with chronic heart failure (CHF), anemia is associated with more severe symptoms and worse prognosis. Erythropoiesis-stimulating proteins (ESPs) increase hemoglobin and may be of therapeutic benefit. We investigated the pharmacokinetics and pharmacodynamics of the long-acting ESP, darbepoetin alfa, administered on 2 occasions 1 month apart to 30 healthy subjects and 33 patients with symptomatic CHF and anemia (hemoglobin相似文献   

Pharmacokinetics of darbepoetin alfa after intravenous or subcutaneous administration in patients with non-myeloid malignancies undergoing chemotherapy

BACKGROUND AND OBJECTIVE: The pharmacokinetics of darbepoetin alfa after intravenous (IV) administration in the oncology setting have not been previously reported. The objective of this study was to evaluate the pharmacokinetics of IV or subcutaneous (SC) darbepoetin alfa in patients with non-myeloid malignancies undergoing multicycle chemotherapy. METHODS: Fifty-six patients (haemoglobin 相似文献   

The relative dosing of epoetin alfa and darbepoetin alfa in chronic kidney disease

ABSTRACT

Objective: The purpose of this study was to review and analyze current research to evaluate the dose ratio of epoetin alfa and darbepoetin alfa for the treatment of anemia in chronic kidney disease (CKD) and to identify determinants of the variation in epoetin alfa: darbepoetin alfa dose ratios across studies.

Methods: A systematic review of the literature for comparative switch and non-switch studies of epoetin alfa and darbepoetin alfa treatments in CKD for the period 2000–2005 was performed. Two reviewers independently assessed the quality of the information. Data on the study design and outcomes were collected for each selected study. The dose ratio from epoetin alfa to darbepoetin alfa was calculated for each study, and the results were reported stratified by study characteristics. To control for differences in study design and characteristics that could explain the variability in the relative dosages of the two agents across studies, multivariate regression analysis was conducted. Based on these results, a dose conversion ratio for Canada was estimated.

Results: A total of 21 studies involving 16?378 patients exposed to epoetin alfa or darbepoetin alfa in CKD were identified. Univariate analysis of the dose ratios indicated a mean dose ratio of 217:1 (IU of epoetin alfa:µg of darbepoetin alfa). Results from the multivariate analysis demonstrated that the study design (i.e., switch study versus straight comparison studies) and geographical coverage (i.e., United States) affected the results. Based on the multivariate analysis, the dose conversion ratio between epoetin alfa and darbepoetin alfa for Canada was 169:1.

Conclusions: Despite limitations associated with switching studies and the limited total number of studies available, this systematic review based on aggregated results provides further evidence to the clinical community that the dose conversion ratio for epoetin alfa:darbepoetin alfa in CKD patients in Canada is approximately 169:1. At that ratio, treatment with epoetin alfa is 11–18% cheaper than treatment with darbepoetin alfa in Canada.     

Darbepoetin alfa: new indication/new dosage. No proven advantage in chemotherapy-induced anaemia

(1) Current treatments for anaemia in patients receiving cancer chemotherapy include blood transfusion and epoetin alfa and beta. These epoetins correct anaemia in 40% to 65% of patients and reduce the number of patients who require transfusions during the second and third months of treatment by 12-35% in absolute terms. (2) Darbepoetin alfa is slightly more glycosylated than epoetin alfa and beta. It is no more effective than these two drugs in chronic renal failure. Darbepoetin alfa is now approved for the treatment of anaemia in patients who are receiving chemotherapy for non myeloid malignancies. (3) Two placebo-controlled dose-finding studies and two placebo-controlled trials involving nearly 1000 patients in total have shown that darbepoetin alfa decreases the number of transfused patients by 17-25% in absolute terms, and that it probably reduces fatigue. However, one-quarter of patients receiving darbepoetin were nonetheless transfused. (4) In the absence of reliable comparisons, there is no firm evidence that darbepoetin alfa is more effective than other epoetins. (5) According to relatively imprecise company reports, darbepoetin alfa increased the risk of thromboembolic events during clinical trials (6% versus 3%), including pulmonary embolism (1.3% versus 0%); the company also states that darbepoetin alfa does not increase the risk of arterial hypertension, a classical effect of epoetin that is mentioned in the summary of product characteristics (SPC). Placebo-controlled trials and dose-finding studies show no impact on the outcome of cancer, but follow-up is limited and a negative effect cannot be ruled out. The company states that no cases of erythroblastopenia have occurred among more than 70 000 treated patients. (6) According to the SPC, darbepoetin alfa can be given once a week. However, the optimal epoetin dosing schedule is unknown. Epoetin therapy takes several weeks to correct anaemia, whereas transfusion is immediately effective. (7) In practice, darbepoetin alfa seems a little easier to administer than epoetin alfa or beta, but the advantages and disadvantages of these drugs as compared with blood transfusion are not entirely clear.     

Darbepoetin alfa: a novel erythropoiesis-stimulating protein

Darbepoetin alfa is a novel erythropoiesis-stimulating protein developed for the treatment of anemia. It is a hyperglycosylated analog of recombinant human erythropoietin with the same mechanism of action as erythropoietin, but with a three-fold longer terminal half-life after intravenous administration than recombinant human erythropoietin and the native hormone both in animal models and in humans. Clinical studies in patients with chronic renal failure either receiving or not receiving dialysis have shown that darbepoetin alfa is equivalent to recombinant human erythropoietin in terms of increases in hemoglobin concentration, percentage of patients achieving target hemoglobin concentration and average time to reach target hemoglobin concentration, although darbepoetin alfa is administered less frequently (once weekly or every other week). Clinical trials in cancer patients either receiving or not receiving chemotherapy have demonstrated that darbepoetin alfa is safe and effective in alleviating anemia at dose intervals of once every 1, 2 or 3 weeks, and results suggest that it may achieve greater and more rapid responses than recombinant human erythropoietin in cancer patients. Furthermore, an improvement in health-related quality of life has been observed in association with anemia correction using darbepoetin alfa therapy in these patients. Darbepoetin alfa has been approved for intravenous and subcutaneous administration by the European Commission and the FDA for the treatment of anemia in patients with chronic renal failure. Additionally, this product was recently approved by the FDA for the treatment of anemia in patients with nonmyeloid malignancies where anemia is due to the effect of concomitantly administered chemotherapy. The recommended starting dose in chronic renal failure patients is 0.45 microg/kg once weekly for both intravenous and subcutaneous administration, with subsequent titration based on the hemoglobin concentration. In cancer patients, the recommended starting dose is 2.25 microg/kg once weekly by subcutaneous injection and subsequent titration. The adverse event profile of darbepoetin alfa is similar to that of recombinant human erythropoietin in both settings. There are no reports of antibody formation associated with darbepoetin alfa in chronic renal failure patients, and three cases of antibody formation, with neutralizing activity in one of the cases, have been reported in cancer patients. However, no cases of antibody-mediated pure red cell aplasia have been reported. The longer half-life of darbepoetin alfa, together with a similar efficacy and safety profile, confers the clinical advantage over recombinant human erythropoietin of allowing a less frequent dosing (once weekly or every other week versus one to three times weekly in renal patients), thus reducing health-care utilization and probably improving patient compliance.