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.     

Therapeutic effects of epoetin zeta in the treatment of chemotherapy-induced anaemia

ABSTRACT

Objective: To perform an open, non-controlled, multiple-dose, international, multicentre, phase III study to evaluate epoetin zeta, a biosimilar epoetin referenced to epoetin alfa, for the treatment of chemotherapy-induced anaemia in patients with cancer.

Methods: Safety, tolerability and efficacy of subcutaneously administered epoetin zeta were assessed in 216 patients with solid tumours or non-myeloid haematological malignancies receiving chemotherapy and at risk of transfusion.

Results: A significant (p?<?0.0001) increase in mean haemoglobin (Hb) level (1.8?g/dL) was observed between baseline and week 12 (intent-to-treat population); 176/216 (81.5%) patients achieved a response (increase in Hb?≥?1?g/dL or reticulocyte count ≥40?000 cells/μL) by week 8. Over the treatment period, 231 treatment-emergent adverse events were experienced by 91 patients; 9/216 (4.2%) experienced a clinically significant thrombotic event within the first 12 weeks of epoetin zeta treatment, significantly lower than the assumed 18% baseline incidence (p?<?0.0001) based on historical data from epoetin trials. No transfusion was necessary for 175/216 patients (81.0%) and quality of life improved over the study. No patients developed anti-erythropoietin antibodies. Sponsor trial no: CT-830-05-0009.

Conclusion: This study demonstrates that subcutaneously administered epoetin zeta is well-tolerated and has efficacy in the treatment of anaemia in patients with cancer receiving chemotherapy and at risk of transfusion.     

Epoetin delta is effective for the management of anaemia associated with chronic kidney disease

ABSTRACT

Objective: To demonstrate the efficacy and safety of epoetin delta for the treatment of anaemia in dialysis patients with chronic kidney disease (CKD).

Research design and methods: This was a 12‐week, randomized, double-blind, active-comparator study. CKD patients who were naïve to epoetin treatment and had haemoglobin < 10?g/dL were randomized to epoetin delta 15, 50, 150, or 300 IU/kg or epoetin alfa 50 IU/kg. Patients initially entered a correction phase until they recorded haemoglobin of ≥ 11.5?g/dL for two consecutive weekly measurements or one haemoglobin measurement of ≥ 13?g/dL (correction success). A maintenance phase followed where the dose was adjusted to maintain haemoglobin ≥ 10.5?g/dL. Maintenance success was defined as haemoglobin > 10.5?g/dL at Week 12. Total success was defined as achieving maintenance and correction success.

Main outcome measures: The primary objective was to demonstrate that the proportion of patients achieving total success was greater in the pooled 150?IU/kg and 300?IU/kg groups compared with the 15?IU/kg dose group.

Results: Total success was achieved in 55.6% of patients in the pooled highest epoetin delta group compared with 4.5% in the lowest dose group. There was no significant difference in total success for the epoetin delta and epoetin alfa 50?IU/kg groups. Significant increases in haemoglobin and haematocrit levels were observed in the 150 and 300?IU/kg dose groups. Adverse events occurred at frequencies expected for this patient group.

Conclusions: Epoetin delta was effective in increasing haemoglobin levels in patients with baseline haemoglobin of < 10?g/dL.     

Relationship between hemoglobin level and quality of life in anemic patients with chronic kidney disease receiving epoetin alfa

ABSTRACT

Objectives: To evaluate the relationship between hemoglobin (Hb) level and quality of life (QOL) in anemic patients with non-dialysis chronic kidney disease receiving epoetin alfa.

Patients and methods: A post-hoc analysis using data from a multicenter, open-label, prospective study of epoetin alfa for anemia in patients with chronic kidney disease not on dialysis was conducted. The relationship between Hb and QOL was analyzed using correlation and longitudinal analyses, the latter adjusting for sample selection bias. The Linear Analog Scale Assessment (LASA) and the Kidney Disease Questionnaire (KDQ) subscales were used to measure QOL. The impact of an incremental 1?g/dL increase in Hb level on LASA and KDQ scores was determined using an incremental analysis.

Results: A total of 1183 and 1044 patients formed the study populations for the LASA and KDQ analyses, respectively. There was a positive and significant relationship between Hb levels and QOL (?p < 0.05). Using non-linear regression analysis, we characterized the sigmoid-shape of the relationship between Hb levels and QOL scores. Hemoglobin change was a statistically significant determinant of QOL improvement for both LASA and KDQ scales (?p < 0.05). The model predicted that, based on a 2?unit change in Hb, the greatest incremental QOL improvement per unit of Hb increase occurred when Hb was in the range of 11 to 12?g/dL.

Conclusions: This study demonstrates that, beyond the well-known relationship between Hb increases and QOL improvements, the maximal incremental gain in QOL occurred when Hb reached 11 to 12?g/dL. This suggests that treating anemic patients with non-dialysis chronic kidney disease until their Hb level reaches 12?g/dL will result in the greatest QOL improvement per Hb unit increase. The analyses were conducted based on an open-label study of epoetin alfa and could be further validated using a randomized, controlled trial, comparing incremental gains in QOL associated with treatment initiation at varying levels of Hb across arms.     

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.     

Dosing patterns,drug costs,and hematologic outcome in anemic patients with chronic kidney disease switching from darbepoetin alfa to epoetin alfa

ABSTRACT

Objective: To compare real-world dosing patterns, drug costs, and hematologic outcome in anemic chronic kidney disease (CKD) patients, not receiving dialysis, who switched from darbepoetin alfa (DARB) to epoetin alfa (EPO) in a community practice setting.

Research design and methods: This retrospective observational chart review from a US nephrology clinic included 153 anemic CKD patients ≥ 18 years of age who did not receive dialysis during the study period, switched from DARB to EPO between 8/2003 and 8/2005, and received ≥ 2 doses of both agents. Paired t-test and McNemar's chi-square were performed comparing pre-switch and post-switch outcomes.

Results: Mean interval between doses increased from 24.3 ± 11.1 days with DARB to 28.8 ± 19.8 days with EPO (?p = 0.001). Weighted mean pre-switch weekly dose for DARB was 25?µg, while weighted mean post-switch weekly dose for EPO was 7090 Units, resulting in a dose ratio (Units EPO:µg DARB) of 287:1. These doses resulted in mean weekly costs of $110 (DARB) and $86 (EPO). Mean hemoglobin (Hb) levels increased over time from 10.8?g/dL at 6 months pre-switch to 11.1?g/dL 6 months after EPO initiation (?p = 0.0132). Mean Hb levels were > 11?g/dL, but below 12?g/dL, while patients received EPO.

Conclusions: Patients switching from DARB to EPO had a greater mean interval between doses, lower drug costs, and consistently maintained recommended Hb levels over time.

Limitations: The reverse direction (EPO to DARB) was not investigated. Although treatment outcomes were not assessed in a randomized, controlled setting, the study's observational nature provided actual evidence in a real-world setting.     

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,open-label comparison of epoetin alfa extended dosing (80 000 U Q2W) vs weekly dosing (40 000 U QW) in patients with chemotherapy-induced anemia

ABSTRACT

Objective: This randomized, open-label, multicenter study compared the efficacy and safety of epoetin alfa (EPO) 80 000 U every 2 weeks (Q2W) to the FDA-approved regimen of 40 000 U weekly (QW) in patients with chemotherapy-induced anemia.

Research design and methods: A total of 310 patients with nonmyeloid malignancy and baseline hemoglobin (Hb) < 11?g/dL who were scheduled to receive chemotherapy for a minimum of 12 weeks were randomized to EPO Q2W or QW for up to 12 weeks, with dose modification to maintain Hb at approximately 12?g/dL. Efficacy analyses used the per-protocol population (patients who completed the study with a value for Hb change) for the primary endpoint only and the modified intent-to-treat (mITT) population (patients who received study drug and had at least one postbaseline Hb value) for the primary and secondary endpoints.

Results: Analysis of the primary endpoint revealed that the mean change in Hb from baseline to study end was comparable between the Q2W and QW groups in the per-protocol population (1.6?g/dL vs 1.8?g/dL, respectively; treatment difference, ?0.2?g/dL; one-sided 95% confidence interval [‐0.56, ‐]); similar results were observed in the mITT population. Among patients on study at Day 29, 9.6% (13/135) and 11.1% (14/126) of patients in the Q2W and QW groups, respectively, received a transfusion between Day 29 and the end of the study (p = 0.709). Dose withholds (21% vs 42%, p < 0.001) and dose reductions (41% vs 59%, p = 0.003) were less common for Q2W than QW. Safety profiles were similar between groups; clinically relevant thrombotic vascular events occurred in 8% of patients in each group. The open-label dosing and the patient attrition rate did not appear to influence overall study results.

Conclusions: Extended dosing (80 000 U Q2W) and once-weekly dosing (40 000 U QW) of EPO provided comparable safety and efficacy for chemotherapy-induced anemia.     

A prospective observational study of the effectiveness,safety, and effect on fatigue of darbepoetin alfa for the treatment of chemotherapy-induced anaemia

ABSTRACT

Objective: Anaemia is common in cancer patients treated with chemotherapy. Darbepoetin alfa (DA) is the only erythropoiesis-stimulating protein approved for administration at weekly and every-three-week intervals in cancer patients receiving chemotherapy. This article investigates the effectiveness, tolerability and effect on fatigue of DA.

Methods: Prospective, observational study performed in 30 Spanish centres. Eligible patients were ≥?18?years of age, anaemic (haemoglobin [Hb] ≤?11?g/dL), with non-myeloid malignancies, receiving chemotherapy. DA (150?μg) was administered weekly for a maximum of 16?weeks (dosage doubled if Hb increased <?1?g/dL after 4?weeks).

Main outcome measures: Haematopoietic response (Hb increase ≥?2?g/dL or Hb ≥?12?g/dL in the absence of transfusions in the previous 28?days), transfusion required between Weeks 5 and 16 and fatigue measured by the Fatigue subscale of the Functional Assessment of Cancer Therapy.

Results: 293 adults were recruited (56.4% women), with lymphoproliferative malignancies (44.3%) or solid tumours (55.7%). Baseline Hb was 9–11?g/dL in 83.7% of patients. Sixty-four per cent (95% CI: 58.1–69.4%) had a haematopoietic response and 12% required transfusions. After adjusting for performance status, concomitant diseases and chemotherapy type, an increase in Hb level was significantly associated with an improvement in Fatigue subscale (+1.9 points per 1?g/dL). Only 2% of patients had treatment-related adverse events: thromboembolic pulmonary disease (0.3%); hypersensitivity reaction (0.3%); local pain following DA administration (0.3%); insomnia (0.3%); thrombocytosis (0.3%) and deep vein thrombosis (0.3%).

Conclusions: Fixed-dose DA administered once weekly seems to be an effective, well-tolerated treatment for chemotherapy-induced anaemia in patients with non-myeloid malignancies, and there is an indication of a possible benefit on fatigue in the clinical practice.     

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.     

Pharmacokinetics and pharmacodynamics of epoetin alfa once weekly and three times weekly

OBJECTIVE: To compare the pharmacokinetics, pharmacodynamics, and tolerance of epoetin alfa administered subcutaneously (s.c.) once weekly (q.w.) and three times weekly (t.i.w.). METHODS: An open-label, randomized, parallel-design study was conducted in 36 healthy adults with hemoglobin (Hb) levels of 11.7 14.0 g/dl for women and 13.0-14.8 g/dl for men. Subjects were randomized to epoetin alfa 150 IU/kg s.c. t.i.w. or 40,000 IU s.c. q.w. for 4 weeks. Serum erythropoietin concentrations were measured using a validated enzyme-linked immunosorbent assay (ELISA). Pharmacokinetic parameters [peak serum concentration (Cmax), mean predose trough concentration (Cmin), time to Cmax (tmax), clearance after s.c. administration (CL/F), area under the plasma concentration time curve (AUC), and terminal elimination half-life (t 1/2)] were calculated using model-independent methods. Mean changes from baseline and AUC of percentage reticulocytes, Hb, and total red blood cell (RBC) concentrations over the 1-month study period were calculated. RESULTS: The Cmax values for serum epoetin alfa q.w. were six times and AUC(0-168) values three times that of the t.i.w. regimen. Time profiles of changes in percentage reticulocytes, Hb, and total RBC over 1 month were similar between regimens. The rate of increase in Hb was similar for the two groups, and both groups exhibited a 3.1-g/dl increase in mean Hb levels from baseline through day 29. Changes in ferritin levels were generally similar between groups and reflected expected use of iron stores for Hb production. Epoetin alfa administered t.i.w. or q.w. was well tolerated and no serious adverse events occurred. CONCLUSION: The pharmacodynamic responses were equivalent between groups despite expected differences in total erythropoietin exposure. These results indicate that the epoetin alfa 150 IU/kg t.i.w. and 40,000 IU q.w. regimens can be considered clinically equivalent.     

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.     

Effectiveness and safety of recombinant human erythropoietin beta in maintaining common haemoglobin targets in routine clinical practice in Europe: the GAIN study

ABSTRACT

Objective: The Gain effectiveness in Anaemia treatment wIth NeoRecormon^* (epoetin beta) study (GAIN) evaluated the effectiveness and safety of recombinant human erythropoietin beta in correcting and/or maintaining common haemoglobin (Hb) targets in routine clinical practice in Europe.

Research design and methods: European 18-month observational, prospective clinical practice study across 217 centres from 13 countries. During a 3-month retrospective period, patients received any erythropoiesis stimulating agent (ESA). For the subsequent 18-month study phase, patients receiving intravenous (IV) epoetin beta or any other ESA were recommended to be switched to subcutaneous (SC) epoetin beta. Presence of anti-erythropoietin antibodies (AEAB) and related outcomes was investigated before and during the study.

Clinical trial registration: ClinicalTrials.gov number: NCT00551603.

Main outcome measures: Correction and maintenance of Hb levels within recommended target range and mean dose requirement to correct and maintain target Hb levels.

Results: A total of 4264 patients on haemodialysis received an ESA for treatment of renal anaemia. During the study period, the number of patients who maintained Hb levels in the recommended target range of 10–12?g/dL increased from 57% to 62%. Administration of SC epoetin beta resulted in a 24% lower mean dose requirement to maintain target Hb levels compared to IV administration (p?<?0.001). Considerable differences were observed between countries in the study. No patients developed pure red cell aplasia associated with AEAB during observation.

Conclusion: This observational study suggests that haemodialysis patients who are receiving any ESA via SC or IV administration for treatment of their renal anaemia can be safely and effectively switched to SC epoetin beta to achieve or maintain the currently recommended Hb targets. SC required a lower dose than IV administration to maintain similar efficacy, thereby potentially lowering the drug costs.

Trial registration: ClinicalTrials.gov identifier: NCT00551603.     

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.     

Preference for monthly darbepoetin alfa dosing in patients with chronic kidney disease not receiving dialysis

ABSTRACT

Objective: To determine patient preference for once-weekly Epoetin alfa versus once-monthly (QM) darbepoetin alfa in patients with chronic kidney disease (CKD) not receiving dialysis.

Methods: AMPS (Aranesp Monthly Preference Study) consisted of two studies of similar design, each with a 2-week screening/baseline period, a 20-week QM darbepoetin alfa dosing period, and an 8-week follow-up period. Patients aged ≥18 years had a nephrologist-reported diagnosis of CKD but were not receiving dialysis, and were required to have at least two hemoglobin levels within 10–12?g/dL and to have been receiving a stable dose (< 25% change) of once-weekly or once- every-other-weekly Epoetin alfa for at least 8 weeks. At week 21, patients could continue on QM darbepoetin alfa or revert back to their previous Epoetin alfa regimen. The primary analysis assessed patient preference at week 21 for QM darbepoetin alfa versus previous onceweekly Epoetin alfa.

Results: AMPS enrolled 442 patients: 54% were female, 67% were Caucasian, and mean (SD) age was 68.3 (13.5) years. At week 21, 346 patients remained on study. Of the patients converted from once-weekly Epoetin alfa, 86% (138/161) preferred darbepoetin alfa QM, and of all patients who expressed a preference, regardless of previous Epoetin alfa dosing frequency, 96% (305/319) preferred QM darbepoetin alfa. Mean (SD) hemoglobin at week 29 of the study was similar to mean hemoglobin at baseline (for those who completed the study and were receiving QM darbepoetin alfa at week 29: 11.2 [1.1]?g/dL at week 29 versus 11.4 [0.7]?g/dL at baseline). QM darbepoetin alfa was well tolerated.

Conclusion: These data show that the majority of study patients preferred QM darbepoetin alfa to more frequent Epoetin alfa, and that QM darbepoetin alfa maintained hemoglobin levels at week 29 and was well tolerated over the study period. The single-item questionnaire could be a potential limitation of this study and further investigation with a multi-question instrument may be helpful in confirming these results.     

Bioequivalence of recombinant human FSH and recombinant human LH in a fixed 2 : 1 combination: two phase I,randomised, crossover studies

ABSTRACT

Objectives: To assess bioequivalence of recombinant human follicle stimulating hormone (r-hFSH, follitropin alfa) and recombinant human luteinising hormone (r-hLH, lutropin alfa) in a fixed 2?:?1 combination (Pergoveris) compared with injection of each of the hormones separately.

Research design and methods: Two, two-way crossover, phase I studies in healthy female volunteers after gonadotrophin-releasing hormone agonist down-regulation. Volunteers were randomised to the order in which they received subcutaneous injections. In the r-hFSH study, volunteers received one injection of r-hFSH (300?IU) and one of r-hFSH (300?IU)/r-hLH (150?IU) ≥?7 days apart; in the r-hLH study they received r-hLH (450?IU) and r-hFSH (900?IU)/r-hLH (450?IU) >?21 days apart.

Main outcome measures: The serum concentration–time profiles of FSH in the r-hFSH study and LH in the r-hLH study from zero to the last measurable concentration (AUC_0–last) and the peak FSH/LH serum concentrations (C_max) were assessed by non-compartmental analysis. The pre-defined range for bioequivalence was 0.8–1.25 for 90% confidence intervals (CI) of the ratio (fixed combination/single gonadotrophin) of the mean for each pharmacokinetic parameter.

Results: Bioequivalence criteria were met for the r-hFSH study (n = 34) for C_max (ratio of means 1.0024, 90% confidence interval (CI) 0.9611–1.0454) and AUC_0–last (ratio of means 1.0167, 90% CI 0.9933–1.0407), and for the r-hLH study (n = 63) for C_max (ratio of means 0.9687, 90% CI 0.9194–1.0207) and AUC_0–last (ratio of means 0.9753, 90% CI 0.8990–1.0581). In the r-hFSH study, 20 adverse events (AEs) were reported after injection of r-hFSH and 20 after r-hLH/r-hFSH. In the r-hLH study, 179 AEs were reported after injection of r-hLH and 193 after the fixed-dose combination. Across both studies, headache was the most commonly reported AE. No serious AEs occurred.

Conclusions: These studies demonstrated bioequivalence between r-hFSH and r-hLH administered alone or in fixed 2?:?1 combination. The 2?:?1 combination of follitropin alfa and lutropin alfa allows administration of both recombinant gonadotrophins in a single injection.     

Dosing patterns,hematologic outcomes,and costs of erythropoietic agents in predialysis chronic kidney disease patients with anemia

ABSTRACT

Objective: Few observational studies have evaluated the use of epoetin alfa (EPO) and darbepoetin alfa (DARB) in chronic kidney disease (CKD) patients with anemia. The objective of this study was to investigate dosing patterns, hematologic outcomes, and intervention costs with EPO and DARB in anemic CKD patients treated in an ambulatory care setting.

Methods: This was a multicenter, retrospective, chart review of predialysis CKD patients with anemia treated with EPO or DARB. Charts were sequentially selected from 435 EPO and 432 DARB patients naive to erythropoietic therapy and treated for ≥ 24 weeks. Hemoglobin (Hb) levels, dates, and EPO/DARB doses were recorded. Drug costs using 2005 wholesale acquisition costs (WAC) and Federal Supply Schedule (FSS) pricing were based on the mean cumulative drug dose over the 24‐week study period.

Results: A total of 393 EPO and 396 DARB charts met all criteria with predominantly male subjects (EPO: 94%; DARB: 96%). Mean baseline GFR and Hb levels were similar. Once-weekly and extended dosing (≥ Q2W) was common in both groups. At Weeks 4, 8, and 12 following initiation of therapy, a greater proportion of EPO than DARB patients reached target Hb levels (≥ 11?g/dL) (?p < 0.0001); at Week 24, all patients reached target Hb levels. Mean 24‐week cumulative doses were EPO 279?336 ± 68?302 units and DARB 1084 ± 246?µg. Drug cost was higher for DARB independent of pricing utilized (WAC: EPO = $3400, DARB = $4726; FSS: EPO = $1528, DARB = $2379).

Conclusions: Extended dosing (≥ Q2W) was common in EPO- and DARB-treated patients with CKD-related anemia, with EPO-treated patients experiencing a significantly greater hematologic response (at Weeks 4, 8, and 12). In addition, drug cost was 39–56% higher in the DARB group. The male predominance may limit generalizability, warranting further research in other populations.     

Utilization of darbepoetin alfa in relation to cancer patients’ hemoglobin levels

ABSTRACT

Objective: Previous labeling and guidelines recommended initiating erythropoiesis agents (ESAs) for chemotherapy-induced anemia (CIA) at hemoglobin (Hb) levels <?11?g/dL, maintaining near 12?g/dL, and withholding at ≥?13?g/dL. This study analyzed adherence with recommendations in administration of darbepoetin (DA) to cancer patients.

Design, setting, and participants: Retrospective analysis of Hb levels at which DA was administered using Varian electronic medical records (EMRs). The dataset comprises 141?694 cancer patients from 82 sites across 13 states. The study evaluated DA administrations with respect to recorded Hb for 8988 patients from 1/1/05 to 5/31/07.

Main outcome measures: Proportion of DA admin­istrations at Hb ≥?12 and Hb ≥?13?g/dL. Hb level was analyzed for all administrations, stratified by year and anemia type (CIA, anemia-of-cancer, and myelodysplastic syndrome).

Results: There were 51?111 DA administrations with Hb results. The proportion of administrations at Hb ≥?12?g/dL was 7.2% and at Hb ≥?13?g/dL was 0.6%, and for CIA 6.9%/0.6%, anemia of cancer (AOC) 8.8%/0.8%, and myelodysplastic syndrome (MDS) 6.5%/0.6%. The propor­tion of all DA administrations at Hb ≥?12?g/dL and ≥?13?g/dL declined from 8.6% to 5.3% (?p < 0.0001) and from 0.7% to 0.4% (?p < 0.0007), respectively during 1/1/05–5/31/07.

Conclusions: In this population, DA administration at Hb ≥?12?g/dL and Hb ≥?13?g/dL occurred in 7.2% and 0.6% of administrations, respectively, a ≈?93% adherence rate with recommendations. Further research is required to under­stand dose titrations at Hb 12–13?g/dL, and whether similar patterns are observed for other ESAs, and in other practice settings. This study provides context for the debate regarding the utilization, benefits and risks of ESAs in cancer patients.     

Effect of a continuous erythropoietin receptor activator (C.E.R.A.) on stable haemoglobin in patients with CKD on dialysis: once monthly administration*

ABSTRACT

Aims: This Phase II study aimed to determine the optimal dose and administration schedule of continuous erythropoietin receptor activator (C.E.R.A.) given subcutaneously (SC) in patients receiving dialysis converting directly from SC epoetin therapy 1–3 times/week. An extension phase examined long-term safety and efficacy.

Methods: Patients were assigned to one of three C.E.R.A. dose groups determined by multiplying the previous weekly dose of epoetin by one of three ratios (0.4/150, 0.8/150, 1.2/150 for groups A, B and C, respectively). Within each group, patients were randomized to once weekly (QW), once every 3 weeks (Q3W) and once monthly (Q4W) schedules. Dose adjustments were not permitted for the first 6 weeks. The core study period was 19 weeks (21 weeks in the Q4W cohorts). Patients could enter a 12?month extension period at the same schedule, aiming to maintain haemoglobin (Hb) at 11–12?g/dL.

Results: 137 patients entered the core period, and 62 continued into the extension period. A dose-dependent relationship was seen in the primary efficacy variable, change in Hb standardized to a 6 week period (?p < 0.0001), but effect was independent of schedule. Hb levels were maintained throughout the study, with few dose changes. C.E.R.A. was generally well tolerated and the most frequent adverse event was hypotension.

Conclusion: The results suggest that SC C.E.R.A. at up to once monthly intervals provides stable maintenance of Hb levels in dialysis patients converting directly from epoetin 1–3 times/week. Achieving tight Hb control with few dose adjustments at extended administration intervals may offer health benefits and improvements in resource management.

Trial registration: ClinicalTrials.gov identifier: NCT00364832.     

A study of the response of elderly patients with end-stage renal disease to epoetin alfa or beta

BACKGROUND: Anaemia correction in patients with end-stage renal disease has been enhanced following the use of epoetin alfa or beta and there are a number of studies detailing its application. Dialysis centres are dealing with greater numbers of elderly patients and anaemia correction in these individuals may differ by virtue of co-existing comorbidity and their age. OBJECTIVE: The aim of this study was to examine the response of the elderly patients to anaemia correction using a locally devised anaemia correction protocol while receiving dialysis. METHODS: An incident, non-randomised, cohort observational study in a single centre was used to compare the correction of anaemia in a population of elderly (> or =65 years of age) and young dialysis patients. All incident patients starting peritoneal dialysis and haemodialysis (HD) between January 1998 and December 2000 were selected and treated using a locally devised anaemia correction protocol and observed for at least 1 year. Anaemia correction following adjustments for factors such as age, comorbidity, dialysis type, dialysis access type and predialysis nephrological care was assessed. RESULTS: 198 patients commenced dialysis with 86 elderly patients (mean age +/- SD 73.7 +/- 4.9 years). The elderly patients had similar periods of predialysis nephrological care as the younger patients. Most patients received HD and required a tunnelled dialysis catheter (TC) as vascular access. Equivalent numbers of elderly patients received peritoneal dialysis. Comorbid scores were greater in the elderly and patient survival was dependent upon these comorbid factors. Following the strict use of TCs, patient survival was similar to those patients commencing HD with arterio-venous fistulae.Anaemia correction in the elderly was similar to the younger patients, with a median haemoglobin of 11.3 g/dL. By 6 months of dialysis, most patients achieved the UK Renal Association anaemia correction standard (haemoglobin above 10 g/dL). The elderly patients maintained significantly higher serum ferritin levels throughout (median 209 microg/L) and required less epoetin alfa or beta (median 91.6 units/kg/wk), indicating that functional iron deficiency in the elderly dialysis patients is less. Intravenous iron sucrose doses were similar in both age groups and iron overload (serum ferritin above 800 microg/L) had been avoided following the use of the intravenous iron protocol. CONCLUSION: The study has noted that elderly patients responded to anaemia corrective therapies as well as the younger patients, despite greater levels of comorbidity while requiring less epoetin alfa or beta.