Darbepoetin Alfa Administered Every Three Weeks Is Effective for the Treatment of Chemotherapy‐Induced Anemia

The effectiveness and cost-effectiveness of erythropoiesis-stimulating agents (epoetin and darbepoetin) for treating cancer treatment-induced anaemia (including review of technology appraisal no. 142): a systematic review and economic model

BACKGROUND

Anaemia is a common side effect of cancer treatments and can lead to a reduction in quality of life. Erythropoiesis-stimulating agents (ESAs) are licensed for use in conjunction with red blood cell transfusions to improve cancer treatment-induced anaemia (CIA).

OBJECTIVE

To investigate the effectiveness and cost-effectiveness of ESAs in anaemia associated with cancer treatment (specifically chemotherapy).

DATA SOURCES

The following databases were searched from 2004 to 2013: The Cochrane Library, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Web of Science, Cumulative Index to Nursing and Allied Health Literature, British Nursing Index, Health Management Information Consortium, Current Controlled Trials and ClinicalTrials.gov. The US Food and Drug Administration and European Medicines Agency websites were also searched. Bibliographies of included papers were scrutinised for further potentially includable studies.

REVIEW METHODS

The clinical effectiveness review followed principles published by the NHS Centre for Reviews and Dissemination. Randomised controlled trials (RCTs), or systematic reviews of RCTs, of ESAs (epoetin or darbepoetin) for treating people with CIA were eligible for inclusion in the review. Comparators were best supportive care, placebo or other ESAs. Anaemia- and malignancy-related outcomes, health-related quality of life (HRQoL) and adverse events (AEs) were evaluated. When appropriate, data were pooled using meta-analysis. An empirical health economic model was developed comparing ESA treatment with no ESA treatment. The model comprised two components: one evaluating short-term costs and quality-adjusted life-years (QALYs) (while patients are anaemic) and one evaluating long-term QALYs. Costs and benefits were discounted at 3.5% per annum. Probabilistic and univariate deterministic sensitivity analyses were performed.

RESULTS

Of 1457 titles and abstracts screened, 23 studies assessing ESAs within their licensed indication (based on start dose administered) were included in the review. None of the RCTs were completely aligned with current European Union licenses. The results suggest a clinical benefit from ESAs for anaemia-related outcomes and an improvement in HRQoL scores. The impact of ESAs on AEs and survival remains highly uncertain, although point estimates are lower, confidence intervals are wide and not statistically significant. Base-case incremental cost-effectiveness ratios (ICERs) for ESA treatment compared with no ESA treatment ranged from £ 19,429 to £ 35,018 per QALY gained, but sensitivity and scenario analyses demonstrate considerable uncertainty in these ICERs, including the possibility of overall health disbenefit. All ICERs were sensitive to survival and cost.

LIMITATIONS

The relative effectiveness of ESAs was not addressed; all ESAs were assumed to have equivalent efficacy. No studies were completely aligned with their European labelling beyond the starting dose evaluated. There is questionable generalisability given that the included trials were published >20 years ago and there have been many changes to chemotherapy as well as to the quality of supportive treatment. Trial quality was moderate or poor and there was considerable unexplained heterogeneity for a number of outcomes, particularly survival, and evidence of publication bias. Adjustments were not made to account for multiple testing.

CONCLUSIONS

ESAs could be cost-effective when used closer to licence, but there is considerable uncertainty, mainly because of unknown impacts on overall survival.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005812.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Effectiveness of Darbepoetin Alfa for Chemotherapy-induced Anemia When Initiated at Hemoglobin ≤10 g/dL

PURPOSE

Limited data are available to describe the effectiveness of darbepoetin alfa (DA) in terms of hemoglobin (Hb) and transfusion outcomes when initiated at Hb ≤10 g/dL (the threshold specified in the summary of prescribing characteristics). We assessed DA, initiated according to current labeling (Hb ≤10 g/dL), in chemotherapy-induced anemia (CIA).

METHODS

Data for patients with cancer and CIA who initiated DA at Hb ≤10 g/dL were extracted from a database of Amgen-sponsored trials. A comparative analysis was limited to randomized, controlled trials in patients treated with DA or control (placebo/best supportive care). Data for the DA arm(s) of randomized, multiple-arm, or prospective, single-arm trials were also extracted (DA-only analysis; non-front-loaded studies only). Outcomes included Hb increase ≥1 g/dL or ≥2 g/dL during the first 12 weeks of treatment. Crude and Kaplan-Meier proportions of patients who experienced each outcome and time (days) to each outcome were summarized by treatment arm. Meta-analysis (fixed-effects inverse-variance method) was performed to compare outcomes for DA with control.

FINDINGS

The comparative analysis included 4 studies (2 in lung cancer, 1 in lymphoproliferative disease, and 1 in non-myeloid malignancy: DA, n = 261; control, n = 273). The DA-only analysis included 15 studies (n = 3768). In comparative analyses, more patients who received DA than placebo achieved Hb increase of ≥1 g/dL (fixed-effects hazard ratio [HR] = 2.07; 95% CI, 1.62-2.63) or ≥2 g/dL (HR = 2.91; 95% CI, 2.09-4.06). Median times to ≥1 g/dL or ≥2 g/dL increase were 43 or 78 days for DA (not evaluable for placebo). Transfusions were less common in patients who received DA (HR = 0.58; 95% CI, 0.44-0.77). Addition of 2 dose-finding studies did not change the findings of the main comparative analysis. Results were similar in the DA-only analyses.

IMPLICATIONS

This is the first patient-level meta-analysis, to our knowledge, to evaluate the efficacy in terms of Hb response of DA treatment when initiated according to current product labeling in patients with CIA. Limitations include the small number of studies and patients eligible for inclusion in the comparative analyses and the absence of non-Amgen trials of DA. The results of the comparative analysis confirm that DA is more effective than placebo at increasing serum Hb levels and at reducing the need for transfusion in patients with CIA when treatment is initiated at Hb ≤10 g/dL, as per current product labeling.

Hemoglobin level at initiation of darbepoetin alfa: impact on need for transfusion and associated costs in chemotherapy-induced anemia treatment in Europe

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 <euro>130 to <euro>537 (2010-adjusted values). Cost savings from initiating DA at higher versus lower Hb levels were <euro>503-2,226 (2 units transfused) and <euro>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.

A final analysis from the CHOICE study examining darbepoetin alfa use for chemotherapy-induced anaemia in current European clinical practice

OBJECTIVES

The CHOICE study was a prospective, multicentre, observational study designed to assess the level of adherence in current clinical practice to the European product label and the EORTC guidelines for the treatment of chemotherapy-induced anaemia with darbepoetin alfa (DA).

METHODS

Hb levels and red blood cell (RBC) transfusion requirements were evaluated among 1900 patients with solid tumours in 11 European countries. The primary outcome measure was the proportion of patients with a target Hb level of ≥10-≤12 g/dL after 9 weeks' DA treatment.

RESULTS

The full analysis set (FAS) comprised 1887 patients (mean ± SD age 62.4 ± 11.4 years) divided into categories by baseline Hb < 9 g/dL (n = 281); 9-<10 g/dL (n = 770); 10-<11 g/dL (n = 695); ≥11 g/dL (n = 114). The proportion of patients who remained on the study at week 9 achieving the target Hb level was 37% (n = 60), 48% (n = 217), 54% (n = 210) and 38% (n = 23) in the subgroups with a baseline Hb level of <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL, respectively. In the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups of the FAS, the number of patients maintaining Hb levels ≥10 g/dL after their first achievement of an Hb value of 10 g/dL was 95 (34%), 372 (48%), 476 (68%) and 87 (76%), respectively. The Kaplan-Meier percentages of patients who required an RBC transfusion from week 5 until end of treatment period were: 29%, 20%, 12% and 17% in the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups, respectively. Kaplan-Meier percentages of patients reaching an Hb level of >13 g/dL were 10%, 9%, 21% and 29%, respectively. Potential bias could not be excluded due to the study's observational nature.

CONCLUSIONS

DA initiation and target Hb ranges adhered to current guidelines in the majority of patients. Furthermore, this study demonstrates faster achievement of the target range and reduced transfusion requirements are associated with initiation of DA at Hb levels of 9-<10 g/dL and 10-<11 g/dL rather than <9 g/dL.

Darbepoetin alpha in the treatment of cancer chemotherapy-induced anemia

Anemia is a common, but underestimated and undertreated, complication of patients with cancer receiving chemo- or radiotherapy, and negatively affects their quality of life (QoL). Erythropoietic proteins (EPS) offer an effective treatment of cancer anemia and ameliorate QoL, although their use requires the correct targeting of hemoglobin increase to avoid thromboembolic complications. Currently the effort is focused on offering patients this effective treatment with reduced frequency of administration. Higher weekly single doses of recombinant human Epo (rHuEpo) either alpha or beta, instead of three times per week, have been proposed for the treatment. The pharmacokinetic and pharmacodynamic characteristics of the hyperglycosylated protein darbepoetin alpha permit even longer inter vals between administrations. Every other week or every three weeks schedules have shown results (erythropoietic response, reduction of transfusion requirements, and improvement of QoL) comparable with those of weekly rHuEpo.

Comparison of darbepoetin alfa dosed weekly (QW) vs. extended dosing schedule (EDS) in the treatment of anemia in patients receiving multicycle chemotherapy in a randomized, phase 2, open-label trial

Background

Chemotherapy-induced anemia (CIA) is responsive to treatment with erythropoiesis-stimulating agents (ESAs) such as darbepoetin alfa. Administration of ESAs on a synchronous schedule with chemotherapy administration could benefit patients by reducing clinic visits and potentially enhancing on-time chemotherapy delivery.

Methods

This phase 2, 25-week, open-label study evaluated the noninferiority of darbepoetin alfa administered weekly vs. as an extended dosing schedule (every 2 or 3 weeks) in patients with CIA. Patients were randomized 1:1 to an extended dosing schedule (EDS: darbepoetin alfa 300 μg Q2W if chemotherapy was QW, Q2W, or Q4W or darbepoetin alfa 500 μg Q3W if chemotherapy was Q3W) or weekly (150 μg QW regardless of chemotherapy schedule). Stratification factors included chemotherapy cycle length, screening hemoglobin (<10 g/dL vs. ≥10 g/dL), and tumor type (lung/gynecological vs. other nonmyeloid malignancies). The primary endpoint was change in hemoglobin from baseline to Week 13.

Results

Seven hundred fifty-two patients (374 QW patients; 378 EDS patients) received ≥1 dose of darbepoetin alfa and were included in the analysis. Demographics and disease state were similar between groups. Seventy-one percent of patients in the EDS group and 76% in the QW group achieved the target hemoglobin of ≥11.0 g/dL. There was a minimal difference in the primary endpoint of mean change in hemoglobin (baseline to Week 13) between the QW and the EDS groups (-0.04 g/dL; 95% confidence interval: -0.26, 0.17 g/dL). The upper limit of the 95% confidence interval was less than the prespecified limit of <0.75 g/dL, supporting noninferiority of the EDS dosing schedule. Reported adverse events were similar between groups. A slight increase in transfusions was reported in the QW group.

Conclusion

Darbepoetin alfa, when administered synchronously with chemotherapy, on an EDS appears to be similarly efficacious to darbepoetin alfa weekly dosing with no unexpected adverse events. This study provides prospective data on how multiple dosing regimens available with darbepoetin alfa can be synchronized with chemotherapy administered across a range of dosing schedules.

Trial registration

ClinicalTrials.gov Identifier NCT00144131.

Darbepoetin alfa 300 or 500 μg once every 3 weeks with or without intravenous iron in patients with chemotherapy-induced anemia

This study evaluated efficacy and safety of darbepoetin alfa administered every 3 weeks (Q3W) at fixed doses of 300 or 500 μg with or without intravenous (IV) iron in treating anemia in patients receiving multicycle chemotherapy. This Phase 2, double-blind, 2 × 2 factorial study randomized patients to one of four treatment arms; darbepoetin alfa 300 μg (n = 62), darbepoetin alfa 300 μg plus IV iron (n = 60), darbepoetin alfa 500 μg (n = 60), or darbepoetin alfa 500 μg plus IV iron (n = 60). Patients had nonmyeloid malignancies, hemoglobin levels ≤10 g dL(-1), and no iron deficiency. Primary endpoint was achievement of target hemoglobin (≥11 g dL(-1)). Secondary endpoints included incidence of transfusions and change in Functional Assessment of Cancer Therapy Fatigue (FACT-F) score from baseline to end of study. Safety was evaluated by incidence of adverse events. No evidence of a statistically significant interaction between darbepoetin alfa dose received and IV iron usage was observed, therefore, results are provided separately comparing darbepoetin alfa doses and comparing IV iron usage groups. Similar proportions of patients receiving darbepoetin alfa 300 or 500 μg achieved target hemoglobin (75 and 78%, respectively); Kaplan-Meier median time to target hemoglobin was 10 and 8 weeks, respectively. More patients receiving IV iron (82%) than not receiving IV iron (72%) achieved hemoglobin target. Adverse events profiles were similar for darbepoetin alfa treatment groups. Transient anaphylactoid reactions were reported in two patients receiving IV iron. Darbepoetin alfa at 300 μg Q3W and 500 μg Q3W showed similar benefit, while added IV iron improved treatment response in these patients.

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

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 > or = 18 years with anemia (hemoglobin <11 g/dL) being treated for nonmyeloid malignancy were randomized 1:1 to receive darbepoetin alfa 300 microg (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 > or =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 > or =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 < or =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

Study 20030232; ClinicalTrials.Gov Identifier: NCT00110955.

The importance of clinical variables in comparative analyses using propensity-score matching: the case of ESA costs for the treatment of chemotherapy-induced anaemia

BACKGROUND

The erythropoiesis-stimulating agents (ESAs) epoetin alfa (EA) and darbepoetin alfa (DA) have comparable efficacy in treating chemotherapy-induced anaemia (CIA). Therapy choice depends on many factors, including cost. Previous estimates of ESA cost differences have been derived from claims data. These data lack clinical variables, such as baseline haemoglobin (Hb) level, which are likely to influence choice of ESA, dosing and costs. We estimated cost differences between DA and EA in patients with cancer receiving chemotherapy, using a propensity-score matched analysis of baseline patient characteristics with and without Hb values to assess the effect of this clinical variable on ESA cost estimates.

METHODS

Data were extracted from electronic medical records in two US databases between January 2004 and December 2006. The study sample included 6743 patients receiving chemotherapy, with one or more visits during the study period, who received an ESA during a chemotherapy episode. Episodes of chemotherapy care were constructed using a 90-day gap in administration to identify the start and end. Patients receiving both DA and EA during their initial chemotherapy episode or with missing data were excluded, representing 42% of patients with CIA receiving an ESA. Drug costs were calculated from the cumulative dose multiplied by 106% of the average sales price (ASP) for DA or EA. Two propensity-score matches were conducted: first using variables available in administrative billing claims systems, then adding the baseline Hb test result. Regression-adjusted cost differences were estimated with and without baseline Hb, using generalized linear models.

RESULTS

Using baseline Hb levels resulted in a better match of the baseline characteristics for the EA and DA treatment groups than the original sample or the matched sample without Hb variables. Mean ESA costs (year 2007 values) for the original sample were $US4171 for EA and $US3811 for DA (mean difference $US360; p < 0.001, standard error [SE] $US99). With propensity-score matching without Hb variables, mean estimated costs were $US3836 for EA and $US3599 for DA (mean difference $US237; p = 0.053, SE $US123). With propensity-score match including Hb variables, mean costs were $US3965 for EA and $US3536 for DA (mean difference $US429; p = 0.001, SE $US125). Cost differences in sensitivity analyses ranged between $US102 (p = 0.201) and $US261 (p = 0.003).

CONCLUSIONS

Addition of baseline Hb level as a variable in propensity score and ESA cost models affects ESA treatment cost estimates in patients with cancer receiving chemotherapy. Cost comparisons based on observational data should use analytical methods that account for differences in clinical variables between treatment groups.

A biobehavioral model for the study of exercise interventions in cancer-related fatigue

Cancer-related fatigue (CRF) is a multifactorial, biobehavioral phenomenon experienced by the majority of persons with cancer. It has negative consequences on the individual's physical functioning and quality of life. An array of biological, psychobehavioral, and functional mechanisms contributes to its occurrence. A relatively large number of studies have examined the effect of physical exercise on CRF over the past few decades. Most of these studies did not specifically examine the effect of physical exercise on the biobehavioral mechanisms underlying CRF. For the most part, these studies have not been guided by a consistent theoretical model. Consequently, the mechanisms by which exercise may ameliorate CRF are not fully elucidated. A theoretical model incorporating fatigue-related biobehavioral variables that could be affected by physical exercise will allow for effective knowledge development in this area and could lead to the development and refinement of exercise protocols that specifically target these mechanisms. Thus, the purpose of this paper is to present a comprehensive theoretical model to guide future research on the effectiveness of exercise interventions in CRF. The proposed model incorporates the biological, psychobehavioral, and functional variables implicated in the induction of CRF.

Predictors of response to erythropoiesis-stimulating agents (ESA) in cancer patients: the role of baseline serum epoetin level

Anemia is the most frequent hematologic abnormality among cancer patients. Its pathophysiology comprises reduction in erythrocyte half-life, poor iron reutilization by the bone marrow, and inadequate response to erythropoietin (EPO), with reduced endogenous EPO (eEPO) levels. Current treatment implies the use of erythropoiesis- stimulating agents (ESA), to which 35-48% of patients show primary resistance. The search for predictors of response to ESA treatment has been inconclusive. Iron or vitamin deficiency, the recent need for transfusion, or a lack of hemoglobin increase within the first 2-4 weeks usually predict resistance to ESA. High serum eEPO levels at treatment initiation (>100-150 mU/ml) may also predict resistance, especially in hematologic malignancies, but the results in solid tumors are not consistent. Although patients with cancer-related anemia show higher eEPO levels than patients without anemia, there is extreme variability among individuals. Future studies are needed to clarify eEPO usefulness in predicting response to ESA treatment.

Effect of age on hemoglobin levels and quality of life following treatment with epoetin alfa in cancer patients

A subgroup analysis comparing elderly (age > or =70 years; n=95) with younger (age <70 years; n=390) patients was performed on data from a prospective, multicenter, open-label study assessing the effects of once-weekly epoetin alfa 40,000 International Units (IU) for 16-20 weeks on hemoglobin (Hb) levels and quality of life (QoL) in anemic adult patients undergoing chemotherapy for solid tumors. There were significant increases in mean Hb levels at 4, 8, 12, 16-20 weeks in both age groups (p<0.0001), but no significant differences between groups (p=0.7). No significant difference was observed in terms of blood transfusion rates across the study between elderly and younger patients (3.2% vs 6.7%, p=0.2). Although QoL was lower in elderly patients at baseline, the relative percentage increases in QoL scores during treatment were similar for both age groups. Thus, once-weekly epoetin alfa was equally effective in treating chemotherapy-related anemia in elderly and younger adult patients, with similar tolerability.

Safety and Efficacy of Darbepoetin Alfa in Previously Untreated Extensive-Stage Small-Cell Lung Cancer Treated With Platinum Plus Etoposide

Purpose

A placebo-controlled, double-blind, randomized, phase III study was conducted in patients with extensive-stage small-cell lung cancer receiving first-line platinum-containing chemotherapy to determine if increasing or maintaining hemoglobin concentration with darbepoetin alfa could increase patient survival.

Patients and Methods

Darbepoetin alfa (300 μg) or placebo was administered once per week for 4 weeks then every 3 weeks for up to six cycles of chemotherapy (carboplatin plus etoposide or cisplatin plus etoposide) plus 3 weeks after the last dose of chemotherapy. Patients with disease progression were observed until death or until all patients completed their end-of-study visit and 496 deaths had occurred. The two coprimary end points were change in hemoglobin concentration from baseline to the end of the chemotherapy period and overall survival; statistical testing of survival was done if change in hemoglobin was significant at P < .05.

Results

The study enrolled 600 patients. Patients' hemoglobin levels dropped due to the myelosuppressive chemotherapy; however, treatment with darbepoetin alfa maintained hemoglobin levels significantly higher than placebo (P < .001). There was no statistically significant difference in overall survival between the treatment groups (hazard ratio [HR], 0.93; 95% CI, 0.78 to 1.11; P = .431). As expected, darbepoetin alfa was associated with a higher incidence of thromboembolic events (darbepoetin alfa, 9%; placebo, 5%). The transfusion risk was lower in the darbepoetin versus placebo group (HR, 0.40; 95% CI, 0.29 to 0.55).

Conclusion

The results of this study did not demonstrate improved survival after treatment with darbepoetin alfa; however, they reinforce the benefit of erythropoiesis-stimulating agents in reducing transfusions and their neutral impact on survival in patients with chemotherapy-induced anemia.

Parenteral iron with erythropoiesis-stimulating agents for chemotherapy-induced anemia

Purpose. To discuss the clinical issues we addressed in the development of our institutional guidelines regarding the assessment of iron stores for cancer- and treatment-related anemia and the administration of parenteral iron with erythropoiesis-stimulating agents (ESAs).

Data sources. Studies published from January 1995 to August 2007 were identified by computer searches of Medline and hand searching of bibliographies of the articles identified via the computer searches. The current clinical practice guidelines were identified by computer searches of the web sites for national professional organizations that represent health care professionals who treat patients with cancer.

Results of data analysis. Hematopoietic responses demonstrate that epoetin alfa and darbepoetin alfa provide similar outcomes for patients with chemotherapy-induced anemia (CIA); however, up to 50% of patients receiving these agents fail to adequately respond. Functional iron deficiency defined as a state of iron-restricted erythropoiesis is likely the primary contributor to the lack of response. Hematopoietic responses following ESA therapy with parenteral iron are substantially higher compared to response with no or oral iron.

Conclusions. Iron stores should be assessed in all patients with cancer- or treatment-related anemia and parenteral iron should be administered to patients receiving ESA therapy to improve hematopoietic response. A unique algorithm that summarizes our institutional guidelines to assess iron stores and administer parenteral iron with ESA therapy in patients with CIA is included. J Oncol Pharm Practice (2008) 14: 5—22.

Erythropoietin pharmacology

Anaemia is a frequent complication in cancer patients and may be multifactorial in origin. Treatment with recombinant human erythropoietin (rHuEPO) is an alternative to red blood cell transfusion. The evidence from clinical trials has established that patients with chemotherapy-induced anaemia with a haemoglobin concentration below 10 g/dl benefit from epoetin therapy. The native glycoprotein hormone consists of 165 amino acids with three N-glycosylation and one O-glycosylation sites. Epoetin and darbepoetin bind to the EPO receptor to induce intracellular signalling by the same intracellular molecules as native EPO. There are some differences in the glycosylation pattern which lead to variations in the pharmacokinetics and pharmacodynamics profiles. Pharmacokinetic and therapeutic studies have examined the use of rHuEPO administered intravenously and subcutaneously and there is accumulating evidence that the latter route has several advantages in cancer patients. After subcutaneous administration, the bioavailability of epoetin is about 20-30% and has a plasma half-life of >24 h. Darbepoetin has a longer half-life after subcutaneous administration of 48 h. The general recommendations are based on evidence from trials in which epoetin was administered 150 U/kg thrice weekly. The recommended initial dose for darbepoetin alpha is 2.25 mug/kg per week. The most serious adverse effects are hypertension, bleeding and increased risk of thrombotic complications. Caution is advised when used in patients who are at high risk for thromboembolic events. In the management of anaemic cancer patients, physicians should closely follow the National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO)/American Society of Hematology (ASH) guidelines.

Extended-dosage-interval regimens of erythropoietic agents in chemotherapy-induced anemia

PURPOSE

The safety and efficacy of extended-dosage-interval regimens of erythropoiesis-stimulating agents (ESAs) for managing chemotherapy-induced anemia (CIA) are reviewed.

SUMMARY

Anemia is a frequent complication of chemotherapy. The ESAs epoetin alfa and darbepoetin alfa have been shown to safely and effectively manage CIA; comparable outcomes have been demonstrated between epoetin alfa 40,000 units once weekly and darbepoetin alfa 200 microg every two weeks. These commonly prescribed regimens necessitate extra clinic visits by cancer patients receiving cyclic chemotherapy. ESA administration can now often be synchronized with a three-week chemotherapy cycle because of the recent approval of darbepoetin alfa 500 microg every three weeks for CIA. However, in the Phase III trial providing the basis for this new dosage recommendation, more than 70% of patients required a 40% reduction in the dosage, resulting in an average dose of 375 microg every three weeks. The extended-dosage-interval regimens have not been associated with an increase in cardiovascular or thrombotic adverse events. Extended-dosage-interval regimens of epoetin alfa are under investigation and may provide additional alternatives. Synchronizing ESA therapy with scheduled chemotherapy visits would help minimize disruptions for patients and caregivers and improve the use of health care resources.

CONCLUSION

Administration of darbepoetin alfa every three weeks offers the convenience of synchronization of treatment with 21-day-cycle chemotherapy in many patients with CIA. Extended-dosage-interval regimens for epoetin alfa are being investigated and show promise.

A randomized, open-label, multicenter trial of immediate versus delayed intervention with darbepoetin alfa for chemotherapy-induced anemia

The optimal hemoglobin concentration at which to initiate erythropoietic therapy for chemotherapy-induced anemia (CIA) is not well defined. This randomized, open-label, multicenter study evaluated the ability of darbepoetin alfa (300 microg every 3 weeks) to maintain hemoglobin levels > or =10 g/dl in patients with CIA (hemoglobin > or =10.5 g/dl and < or =12.0 g/dl) randomized 1:1 to an immediate-intervention group (received darbepoetin alfa immediately) or observation group (received darbepoetin alfa if hemoglobin fell to <10 g/dl). In 201 evaluable patients, there was a significant difference between the two groups in the Kaplan-Meier proportion of patients with a hemoglobin decrease to <10 g/dl during weeks 1-13 (test period) (primary endpoint): 29% for immediate-intervention patients versus 65% for observation patients. Sixty-four patients in the observation group received darbepoetin alfa (delayed-intervention subgroup). The Kaplan-Meier proportion of patients who received transfusions was lower in the immediate-intervention group than in the delayed-intervention subgroup (14% versus 31% for the test period; 17% versus 36% over the whole study). The target hemoglobin level (> or =11 g/dl) was achieved by a higher percentage of patients (crude percentage) in less time in the immediate-intervention group (94% in 2 weeks) than in the delayed-intervention subgroup (73% in 6 weeks); hemoglobin endpoints for the delayed-intervention subgroup were calculated from recalibrated study week 1 (the date patients first received darbepoetin alfa). For both groups, a higher mean change in hemoglobin from baseline led to a greater improvement in Functional Assessment of Cancer Therapy-Fatigue scores. In conclusion, immediate intervention resulted in a significantly lower proportion of patients who experienced a decline in hemoglobin, lower requirement for transfusions, and greater proportion of patients achieving and maintaining the target hemoglobin level.

An extended maintenance dosing regimen of epoetin alfa 80,000 U every 3 weeks in anemic patients with cancer receiving chemotherapy

BACKGROUND

The purpose of this study was to evaluate the safety and efficacy of epoetin alfa (EPO) at an initial dose of 60,000 Units (U) once weekly (QW) followed by extended dosing of 80,000 U every 3 weeks (Q3W) in patients with chemotherapy-induced anemia (CIA).

MATERIALS AND METHODS

Anemic patients (hemoglobin [Hb] < or = 11 g/dl) receiving Q3W chemotherapy for nonmyeloid malignancy were enrolled in this prospective, open-label, single-arm study to receive EPO 60,000 U subcutaneously (SC) QW (initial dosing phase [IDP]) until a target Hb level of 12 g/dl was reached (maximum 12 weeks). Patients who achieved an Hb level of 12 g/dl at any point during the IDP then entered the extended dosing phase (EDP; EPO 80,000 U SC Q3W). Maximum study duration (IDP + EDP) was 24 weeks. The primary endpoint was the proportion of patients achieving a hematopoietic response (Hb increase > or = 2 g/dl from baseline or Hb > or = 12 g/dl) during the IDP.

RESULTS

One hundred fifteen patients were enrolled. During the IDP, 76% (84/110) of patients achieved a hematopoietic response, and 15% (17/115) received red blood cell (RBC) transfusion. Sixty-three percent (73/115) of patients entered the EDP, and 88% (64/73) of these patients maintained a mean Hb level > 11.0 and < or =13.0 g/dl. Two of 73 patients received RBC transfusion during the EDP. Adverse events were consistent with the underlying disease and chemotherapy treatment.

CONCLUSION

These results suggest that initiation of EPO 60,000 U SC QW is effective in the treatment of CIA and that EPO 80,000 U SC Q3W can be an effective extended dosing option.

Assessing symptom burden using the M. D. Anderson symptom inventory in patients with chemotherapy-induced anemia: results of a multicenter, open-label study (SURPASS) of patients treated with darbepoetin-alpha at a dose of 200 microg every 2 weeks

BACKGROUND

Patients with cancer who are receiving chemotherapy often experience chemotherapy-induced anemia (CIA), which is associated with symptoms that reduce quality of life. The M. D. Anderson Symptom Inventory (MDASI) is a brief, self-rating assessment scale that measures the severity of core symptoms and symptom interference with function. The current study used the MDASI to prospectively assess the correlation between hemoglobin and self-perceived cancer-related symptoms in a large patient population with CIA who were receiving darbepoetin-alpha at a dose of 200 mug every 2 weeks.

METHODS

Eligible patients enrolled in this multicenter, open-label study were age > or =18 years, had a nonmyeloid malignancy, were receiving multicycle chemotherapy, and were anemic (hemoglobin < or = 11 g/dL). Hemoglobin was measured every 2 weeks; the MDASI was administered weekly. For hemoglobin-based endpoints, patients were stratified by baseline hemoglobin (< 10 g/dL or > or =10 g/dL).

RESULTS

Of 2422 enrolled patients, 2401 received > or =1 dose of darbepoetin-alpha. Eighty percent of patients (95% confidence limit, 78-82 patients) achieved target hemoglobin levels (> or =11 g/dL) during the study. Patients with a baseline hemoglobin < 10 g/dL had a greater increase in hemoglobin, took longer to achieve the target hemoglobin, and received more red blood cell transfusions than patients with a baseline hemoglobin > or =10 g/dL. The percentage of patients with moderate to severe MDASI scores (> or =5 points) for fatigue, distress, loss of appetite, disturbed sleep, and interference with function was reduced during the study. Improvement in symptom burden was associated with an increase in hemoglobin concentration.

CONCLUSIONS

Treatment with darbepoetin-alpha at a dose of 200 mug every 2 weeks is associated with improvement in symptom burden as measured by the MDASI, a simple tool that may improve symptom management for cancer patients with CIA.

The Effectiveness of Darbepoetin Alfa Administered Every 3 Weeks on Hematologic Outcomes and Quality of Life in Older Patients With Chemotherapy‐Induced Anemia

Chemotherapy-induced anemia (CIA) may substantially impact the health-related quality of life (HRQoL) of older cancer patients. This exploratory analysis evaluated the effect of darbepoetin alfa administered as a fixed dose (300 microg) every 3 weeks (Q3W) on hematologic outcomes, HRQoL, and safety in older (> or =65 years old) versus younger (<65 years old) patients with CIA (hemoglobin <11 g/dl). Patients were categorized by age at screening: <65, > or =65 to <70, > or =70 to <75, > or =75 to <80, and > or =80 years old. Patients who received at least one dose of darbepoetin alfa were included in the analysis; of 1,493 patients, 724 were > or =65 years old. Age did not appear to influence hematologic outcomes after treatment with darbepoetin alfa; in all age categories, similar percentages of patients (78%-80%) achieved the target hemoglobin in approximately the same time (4-5 weeks). Also, the percentage of patients in each age category who received RBC transfusions was reduced from 10%-13% in month 1 to 2%-4% in month 4. Although younger patients reported the greatest improvement in HRQoL scores, approximately one half in each older age category reported clinically significant improvement in fatigue, and improvement in the Energy and Overall Health Assessment and Work Productivity and Activity Impairment scales. There were no treatment-related deaths. Treatment-related thromboembolic events were reported by <1% of patients <65 years old and <1% of patients > or =65 to <70 and > or =70 to <75 years old. Darbepoetin alfa Q3W appeared well tolerated and effective for treating older patients with CIA.

Darbepoetin alfa: An Effective Treatment with Flexible and Simplified Dosing for Anemia in Patients with Cancer

Anemia is common in patients with cancer or myelodysplastic syndrome. Erythropoietic therapy offers an effective way to manage anemia by increasing hemoglobin levels, decreasing transfusion requirements, and alleviating symptoms. We reviewed data showing the feasibility and effectiveness of treatment with the erythropoiesis-stimulating protein darbepoetin alfa at extended dosing intervals to treat anemia in patients with cancer receiving multicycle chemotherapy. We also explored the darbepoetin alfa's potential for treating anemia in patients with myelodysplastic syndrome. Data from clinical studies and drug therapy evaluations confirm that darbepoetin alfa administered weekly, every 2 weeks, and every 3 weeks corrects and maintains hemoglobin levels in patients with chemotherapy-induced anemia. In addition, the data demonstrate that both weight-based and fixed dosing with darbepoetin alfa are effective, and that early intervention to treat anemia has clinical benefits. Darbepoetin alfa also is an effective treatment for anemia in patients with cancer not receiving chemotherapy, at extended dosing intervals of at least 3 weeks. Extended dosing for anemia treatment can provide benefits for patients, caregivers, and clinicians because it reduces the number of clinic visits needed and permits synchronizing anemia treatment with chemotherapy cycles. Data from recent studies suggest that darbepoetin alfa is effective for treating anemia in patients with myelodysplastic syndrome; this potential use is being investigated further in ongoing studies. Thus, darbepoetin alfa is an attractive therapy option for patients with chemotherapy or cancer-induced anemia. It allows increased flexibility and simplified dosing and may offer some benefit in the treatment of anemia in patients with myelodysplastic syndrome.

Darbepoetin??Alfa

Darbepoetin alfa (Aranesp) is an analogue of recombinant human erythropoietin (rHuEPO) produced using recombinant DNA technology. The high number of sialic acid moieties in darbepoetin alfa results in a prolonged half-life and enhanced in vivo biological activity compared with rHuEPO (as demonstrated in animal studies) and permits a reduction in the frequency of administration. Subcutaneous darbepoetin alfa 2.25 microg/kg once weekly or 500 microg once every 3 weeks (with a provision for dose adjustments) is an effective and well tolerated erythropoietic agent in anaemic patients with cancer receiving chemotherapy. In randomised, controlled clinical trials, the drug increased haemoglobin levels and reduced the need for blood transfusions in patients with various types of nonmyeloid malignancies and also ameliorated anaemia-related fatigue, thereby improving their health-related quality of life (HR-QOL) scores. The once-every-3-weeks dosage regimen provides further convenience by offering the possibility of synchronising its administration with most chemotherapy regimens. Direct comparisons between approved dosages of darbepoetin alfa and other erythropoietic agents have not been conducted. Such comparisons would be very helpful in formulating definitive conclusions about their relative efficacy and cost effectiveness. Darbepoetin alfa provides an effective and well tolerated treatment option for the treatment of anaemia in patients with cancer receiving chemotherapy.