Darbepoetin alfa for the treatment of chemotherapy-induced anemia: disease progression and survival analysis from four randomized, double-blind, placebo-controlled trials

The Safety of Erythropoiesis-Stimulating Agents for the Treatment of Anemia Resulting from Chronic Kidney Disease

Chronic kidney disease (CKD) anemia treatment was revolutionized in the late 1980s with the introduction of recombinant human erythropoietin. This and related erythropoiesis-stimulating agents (ESAs) greatly benefited patients by decreasing debilitating symptoms, improving their quality of life, and freeing them from dependence on blood transfusions with their associated complications such as infections, sensitization impeding transplantation, and secondary iron overload. However, even in the initial studies, untoward effects were noted in patients receiving ESAs, including worsening hypertension, seizures, and dialysis access clotting. Later, increased mortality, malignancy progression and even stroke were reported in renal patients. This review focuses on the safety issues of ESAs in CKD patients.

Efficacy and safety of darbepoetin alfa initiated at hemoglobin ≤10 g/dL in patients with stage IV cancer and chemotherapy-induced anemia

Data on efficacy and safety of darbepoetin alfa (DA) administered at hemoglobin (Hb) ≤10 g/dL are limited. In this analysis, we examined DA's efficacy and safety in patients with Stage IV cancers and chemotherapy‐induced anemia (CIA) initiated on DA at Hb ≤10 g/dL. Data for patients with Stage IV cancers and CIA and who initiated DA at Hb ≤10 g/dL were extracted from three phase 3 trials identified in a central database of Amgen‐sponsored DA studies in CIA. Efficacy outcomes were assessed by achievement of Hb increases of ≥1 g/dL and ≥2 g/dL and red blood cell (RBC) or whole blood transfusion requirements. Data were analyzed for all patients with baseline Hb ≤10 g/dL, and by the subgroups of patients with baseline Hb ≥9 to ≤10 g/dL versus <9 g/dL. Crude and Kaplan–Meier proportions of patients who experienced each outcome and time (days) to each outcome were summarized by treatment. Meta‐analysis (fixed‐effects inverse‐variance model) was performed to compare outcomes for DA versus placebo. Safety was assessed by occurrence of adverse events. Data from 213 patients were analyzed: DA, n = 115; placebo, n = 98. More patients in the DA versus the placebo subgroup achieved Hb increase of ≥1 g/dL (72% vs. 36%; HR: 2.92, 95% CI: 1.95, 4.39) and ≥2 g/dL (44% vs. 18%; HR: 2.98, 95% CI: 1.71, 5.21) during the first 12 treatment weeks. Median times to Hb increase of ≥1 g/dL and ≥2 g/dL were 36 days and 78 days for DA, respectively. RBC or whole blood transfusions were less common in patients in the DA versus the placebo subgroup (24% vs. 45%; HR: 0.44, 95% CI: 0.27, 0.73). No new safety issues were reported. Our results confirm that DA use in patients with Stage IV cancer and CIA is more effective than placebo at increasing Hb levels and at reducing transfusion needs when DA treatment is initiated at Hb ≤10 g/dL.

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.

Onco-nephrology: an appraisal of the cancer and chronic kidney disease links

A bidirectional relationship has been observed for kidney disease and cancer. On the one hand, cancer is an important complication noted in kidney disease as well as a major cause of morbidity and mortality in this group. On the other hand, improved cancer treatment has prolonged survival, but also increased the development of acute and chronic kidney disease. The combination of cancer and kidney disease makes it challenging for clinicians to provide comprehensive and safe therapies for this group of patients. As such, clinicians caring for this group must develop expertise and become competent in the practice of a newly evolving subspecialty of nephrology known as 'onco-nephrology'. This brief narrative review will focus on the cancer risk in patients with underlying kidney disease, the therapies such as erythropoiesis-stimulating agents on cancer progression and other outcomes, and the appropriate dosing of anti-cancer agents in patients with underlying kidney disease.

Final results from the prospective phase III WSG-ARA trial: impact of adjuvant darbepoetin alfa on event-free survival in early breast cancer

BACKGROUND

WSG-ARA plus trial evaluated the effect of adjuvant darbepoetin alfa (DA) on outcome in node positive primary breast cancer (BC).

PATIENTS AND METHODS

One thousand two hundred thirty-four patients were randomized to chemotherapy either with DA (DA+; n = 615) or without DA (DA-; n = 619). DA (500 µg q3w) was started at hemoglobin (Hb) levels <13.0 g/dl (<12 g/dl after DA label amendment) and stopped at Hb levels ≥14.0 g/dl (12 g/dl after label amendment). Primary efficacy end point was event-free survival (EFS); secondary end points were toxicity, quality of life (QoL) and overall survival (OS).

RESULTS

Venous thrombosis (DA+: 3.0%, DA-: 1.0%; P = 0.013) was significantly higher for DA+, but not pulmonary embolism (0.3% in both arms). Median Hb levels were stable in DA+ (12.6 g/dl) and decreased in DA- (11.7 g/dl). Hb levels >15 g/dl were reported in 0.8% of cycles. QoL parameters did not significantly differ between arms. At 39 months, DA had no significant impact on EFS (DA+: 89.3%, DA-: 87.5%; Plog-rank = 0.55) or OS (DA+: 95.5%, DA-: 95.4%; Plog-rank = 0.77).

CONCLUSIONS

DA treatment did not impact EFS or OS in routine adjuvant BC treatment.

Pharmacovigilance in practice: erythropoiesis-stimulating agents

Pharmacovigilance (PV) is the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or other problems related to medical products after they have been licensed for marketing. The purpose of PV is to advance the safe use of marketed medical products. Regulatory agencies and license holders collaborate to collect data reported by health care providers, patients, and the public as well as data from systematic reviews, meta-analyses, and individual clinical and nonclinical studies. They validate and analyze the data to determine whether safety signals exist, and if warranted, develop an action plan to mitigate the identified risk. Erythropoiesis-stimulating agents (ESAs) provide an example of how PV is applied in reality. Among other approved indications, ESAs may be used to treat anemia in patients with chemotherapy-induced anemia. ESAs increase hemoglobin levels and reduce the need for transfusions; they are also associated with a known increased risk of thromboembolic events. Starting in 2003, emerging data suggested that ESAs might reduce survival. As a result of PV activities by regulatory agencies and license holders, labeling for ESAs addresses these risks. Meta-analyses and individual clinical studies have confirmed that ESAs increase the risk of thromboembolic events, but when used as indicated, ESAs have not been shown to have a significant effect on survival or disease progression. Ongoing safety studies will provide additional data in the coming years to further clarify the risks and benefits of ESAs.

Prognostic impact of the combination of erythropoiesis-stimulating agents to cancer treatment: literature review

Cancer patients commonly develop anaemia. Erythropoiesis-stimulating agents (ESAs) are frequently used in cancer treatment. Numerous controlled studies indicate that ESAs can raise haemoglobin levels, reduce transfusion requirements and improve quality of life in anaemic cancer patients receiving chemotherapy. They were previously used to enhance response to radiation therapy, via increasing tumour cell oxygenation. Since the 2002 guideline, there has been increasing attention to the safety of ESA treatment in patients with cancer. Two placebo-controlled phase III randomised clinical trials published in 2003 showed evidence of harmful effects of ESAs on survival and/or tumour outcomes. Subsequently, recent trials and several large meta-analyses have confirmed negative impact on survival and/or disease progression. To comprehensively examine whether ESA use affects safety outcomes in cancer patients in different settings (chemotherapy, radiotherapy and targeted therapies), we conducted a literature review of all clinical trials, small and large meta-analyses from 1990 to 2012.

Prevalence and management of anaemia in patients with non-myeloid cancer undergoing systemic therapy: a Spanish survey

BACKGROUND

The present study aimed to provide updated data on anaemia prevalence and management in cancer patients undergoing systemic therapy in Spain.

METHODS

This was a multicenter, observational, cross-sectional study performed in 2008. Eligible patients were ≥18 years, with non-myeloid malignancies treated with systemic therapy [chemotherapy (CT), hormonal therapy or immunotherapy]. Anaemia was defined according to WHO as haemoglobin (Hb) < 12 g/dL.

RESULTS

The study included 214 patients with a median age of 63 years (range 20-91), 58 % women, 73 % with solid tumours, and 79 % with advanced disease. CT was used in 91 % of patients (26 % with platinum compounds), hormonal therapy in 8.5 %, and immunotherapy in 8.5 %. In our study, 48.1 % of patients [95 % confidence interval (CI) 45.2-58.6] showed anaemia (31 % symptomatic): 42.0 % mild (10 ≤ Hb ≤ 11.9 g/dL), 5.6 % moderate (8 ≤ Hb ≤ 9.9 g/dL), and 0.5 % severe (Hb < 8 g/dL). A higher prevalence was observed in patients treated with CT (51 vs. 20 %, p = 0.01), platinum-based CT (70 vs. 47 %, p = 0.01) or palliative CT (61 vs. 39 %, p = 0.003). Anaemia was also more frequent in patients with more than three lines of CT (83 %) and in the fourth or subsequent CT cycle (58 %). Management in the previous 4 weeks in patients with anaemia was: 62 % did not receive treatment (92 % mild), 24 % received erythropoiesis-stimulating agents (ESAs), 14 % received iron and 8.7 % received transfusion.

CONCLUSIONS

In Spanish hospitals, about half of patients with non-myeloid malignancies undergoing systemic therapy fulfilled anaemia criteria (87 % mild). Approximately two-third of patients with anaemia do not receive specific treatment and ESA use is below current guidelines.

Chemotherapy-induced anemia: the story of darbepoetin alfa

BACKGROUND

Prior to the approval of the first erythropoiesis-stimulating agent (ESA) in the early 1990s, red blood cell transfusions were the primary means of treating severe chemotherapy-induced anemia (CIA), with little recourse for those with more mild forms of the condition. The introduction of the ESAs allowed treatment of mild-to-moderate CIA in patients with cancer. It has been a decade since darbepoetin alfa (DA), a second-generation ESA with a longer half-life, became available to patients with CIA.

OBJECTIVE AND METHODS

We present a review of studies on DA in CIA, from its development through to the present day. Medline was searched for randomized clinical trials on DA. Additional trials and meta-analyses on ESAs were incorporated into this review when relevant.

RESULTS

The first publications on DA generally focused on optimal dosing, efficacy and tolerability. In these, it was shown that DA is an effective and well tolerated treatment option to achieve hematopoietic response, regardless of dosing interval. Subsequently, the focus shifted towards meta-analyses on survival data of all ESAs. These reported conflicting results regarding mortality and/or disease progression. However, guidelines for ESA use were updated and, when followed, these make ESAs a well tolerated and effective tool for managing CIA.

CONCLUSIONS

As the past decade has broadened our knowledge on the benefits and risks of CIA management, continued high-quality studies will help to optimize treatment with ESAs in order to maximize quality of life for these patients. The limitation of a literature review of this nature is the complete reliance on previously published research and the availability of these studies using the methodology outlined above.

Erythropoietin or darbepoetin for patients with cancer

BACKGROUND

Anaemia associated with cancer and cancer therapy is an important clinical factor in the treatment of malignant diseases. Therapeutic alternatives are recombinant human erythropoiesis stimulating agents (ESAs) and red blood cell transfusions.

OBJECTIVES

To assess the effects of ESAs to either prevent or treat anaemia in cancer patients.

SEARCH METHODS

This is an update of a Cochrane review first published in 2004. We searched the Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE and other databases. Searches were done for the periods 01/1985 to 12/2001 for the first review, 1/2002 to 04/2005 for the first update and to November 2011 for the current update. We also contacted experts in the field and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials on managing anaemia in cancer patients receiving or not receiving anti-cancer therapy that compared the use of ESAs (plus transfusion if needed).

DATA COLLECTION AND ANALYSIS

Several review authors assessed trial quality and extracted data. One review author assessed quality assessment and extracted data, a second review author checked for correctness.

MAIN RESULTS

This update of the systematic review includes a total of 91 trials with 20,102 participants. Use of ESAs significantly reduced the relative risk of red blood cell transfusions (risk ratio (RR) 0.65; 95% confidence interval (CI) 0.62 to 0.68, 70 trials, N = 16,093). On average, participants in the ESAs group received one unit of blood less than the control group (mean difference (MD) -0.98; 95% CI -1.17 to -0.78, 19 trials, N = 4,715). Haematological response was observed more often in participants receiving ESAs (RR 3.93; 95% CI 3.10 to 3.71, 31 trials, N = 6,413). There was suggestive evidence that ESAs may improve Quality of Life (QoL). There was strong evidence that ESAs increase mortality during active study period (hazard ratio (HR) 1.17; 95% CI 1.06 to 1.29, 70 trials, N = 15,935) and some evidence that ESAs decrease overall survival (HR 1.05; 95% CI 1.00 to 1.11, 78 trials, N = 19,003). The risk ratio for thromboembolic complications was increased in patients receiving ESAs compared to controls (RR 1.52, 95% CI 1.34 to 1.74; 57 trials, N = 15,498). ESAs may also increase the risk for hypertension (fixed-effect model: RR 1.30; 95% CI 1.08 to 1.56; random-effects model: RR 1.12; 95% CI 0.94 to 1.33, 31 trials, N = 7,228) and thrombocytopenia/haemorrhage (RR 1.21; 95% CI 1.04 to 1.42; 21 trials, N = 4,507). There was insufficient evidence to support an effect of ESA on tumour response (fixed-effect RR 1.02; 95% CI 0.98 to 1.06, 15 trials, N = 5,012).

AUTHORS' CONCLUSIONS

ESAs reduce the need for red blood cell transfusions but increase the risk for thromboembolic events and deaths. There is suggestive evidence that ESAs may improve QoL. Whether and how ESAs affects tumour control remains uncertain. The increased risk of death and thromboembolic events should be balanced against the potential benefits of ESA treatment taking into account each patient's clinical circumstances and preferences. More data are needed for the effect of these drugs on quality of life and tumour progression. Further research is needed to clarify cellular and molecular mechanisms and pathways of the effects of ESAs on thrombogenesis and their potential effects on tumour growth.

Darbepoetin alfa in the treatment of anemia in cancer patients undergoing chemotherapy

For years, the treatment of chemotherapy-induced anemia (CIA) consisted of red blood cell transfusions. Major disadvantages of transfusions are their temporary effect and limitation to treatment of severe anemia. In an extensive clinical trial program in patients with CIA, darbepoetin alfa (DA) - a long-acting recombinant human erythropoietin - was proven to be very effective in reducing transfusion needs in patients developing CIA. The administration is suitable with most chemotherapy schemes. Caution is needed in patients with a history of thrombo-embolic events, as a slightly higher incidence of these events is noted in patients treated with darbepoetin alfa or erythropoietin substitution agents (ESAs) in general. In recent years, concerns have been raised about a potential negative influence of these agents on survival. In this respect, it is important to make the distinction between studies on the treatment of existing CIA versus treatment with ESAs outside this indication. On the other hand, it has always been assumed that transfusions were a completely safe treatment, but concerns about a potential negative effect on survival have been raised for transfusions as well. The safety concerns with DA and ESAs in general led to a pharmacovigilance program and an adaptation of the guidelines for treatment of CIA, focusing on treatment of moderate CIA but no longer on mild CIA. Now that the most recent safety data of the pharmacovigilance program of ESAs is almost completed, the clinical impact of the shift to the treatment of only moderate anemia is discussed in this review, which provides a critical view on the indications of DA and the benefit-risk assessment, in order to provide good supportive care without harm to the patient.

Effects of erythropoiesis-stimulating agents on survival and other outcomes in patients with lymphoproliferative malignancies: a study-level meta-analysis

Erythropoiesis-stimulating agents (ESAs) are approved to treat anemia in patients with non-myeloid malignancies receiving myelosuppressive chemotherapy. ESAs reduce transfusion rates, but some clinical studies suggest that ESAs may reduce survival or increase disease progression. This study-level meta-analysis examined the effects of darbepoetin alfa, epoetin alfa or epoetin beta on mortality, disease progression and transfusion incidence in patients with lymphoproliferative malignancies, using randomized, controlled trials of patients receiving chemotherapy and ESAs or standard of care. The odds ratio (OR) for mortality was 1.04 (95% confidence interval [CI], 0.81-1.34, random-effects model, 10 studies); the risk difference was - 0.01 (95% CI, - 0.03-0.02). The OR for disease progression was 1.02 (95% CI 0.81-1.30, random-effects model, five studies). A lower proportion of ESA-treated patients than controls received transfusions (seven studies). In this meta-analysis, ESAs reduced transfusions with no clear effect on mortality or disease progression in patients with lymphoproliferative malignancies receiving chemotherapy.

Effects of erythropoietin receptors and erythropoiesis-stimulating agents on disease progression in cancer

Erythropoiesis-stimulating agents (ESAs) increase red blood cell (RBC) production in bone marrow by activating the erythropoietin receptor (EpoR) on erythrocytic-progenitor cells. Erythropoiesis-stimulating agents are approved in the United States and Europe for treating anaemia in cancer patients receiving chemotherapy based on randomised, placebo-controlled trials showing that ESAs reduce RBC transfusions. Erythropoiesis-stimulating agent-safety issues include thromboembolic events and concerns regarding whether ESAs increase disease progression and/or mortality in cancer patients. Several trials have reported an association between ESA use and increased disease progression and/or mortality, whereas other trials in the same tumour types have not provided similar findings. This review thoroughly examines available evidence regarding whether ESAs affect disease progression. Both clinical-trial data on ESAs and disease progression, and preclinical data on how ESAs could affect tumour growth are summarised. Preclinical topics include (i) whether tumour cells express EpoR and could be directly stimulated to grow by ESA exposure and (ii) whether endothelial cells express EpoR and could be stimulated by ESA exposure to undergo angiogenesis and indirectly promote tumour growth. Although assessment and definition of disease progression vary across studies, the current clinical data suggest that ESAs may have little effect on disease progression in chemotherapy patients, and preclinical data indicate a direct or indirect effect of ESAs on tumour growth is not strongly supported.

Evaluation of clinical use and effectiveness of darbepoetin alfa in cancer patients with chemotherapy-induced anemia

PURPOSE

To investigate the patterns of use of darbepoetin alfa in Spanish centers, and to evaluate its effectiveness in the treatment of chemotherapy-induced anemia under clinical practice conditions.

METHODS

This was an observational, retrospective, multicenter study in adult patients with non-myeloid malignancies who initiated chemotherapy and darbepoetin alfa. Data was collected for up to 16 weeks or until treatment discontinuation.

RESULTS

A total of 685 patients (72.7% with solid tumors and 27.3% with hematologic malignancies) were included in the study. Median age was 64.7 years (range 18.5-88.9 years), 50.7% were women, 82.4% had ECOG status 0-1 and 80.5% had stage III/IV cancer. At darbepoetin initiation, mean hemoglobin (Hb) was 100 g/L (SD 10), with 11.0% and 23.1% of patients below 90 g/L in solid and hematologic malignancies, respectively. A decrease in transfusion requirements was observed between weeks 5-16 with respect to weeks 0-16 (13.3% [95% CI: 10.7 to 15.9] versus 19.0% [95% CI: 16.0 to 22.0]). Hb levels were significantly increased during the treatment (mean change of 10.4 g/L for solid tumors [p < 0.001], and 16.6 g/L for hematologic malignancies [p < 0.001]). The percentage of patients with baseline Hb level <110 g/L who achieved an Hb level ≥110 g/L during the study was 66.5% (95% CI: 62.5% to 70.5%). Six serious adverse reactions were considered related to darbepoetin alfa (thromboembolic events, 1.0%).

CONCLUSIONS

With the limitation of a retrospective design, our results suggest that darbepoetin alfa is a well tolerated treatment that increases hemoglobin levels and reduces the need for transfusion in cancer patients receiving chemotherapy in clinical practice.

Flexible dosing with Darbepoetin alfa for the treatment of chemotherapy-induced anemia

Anemia is frequent in cancer patients with chemotherapy, and has an important negative effect on health-related quality of life (QoL). Darbepoetin alfa belongs to a new class of erythropoietic proteins with a unique molecular structure and interesting properties compared with classic recombinant human erythropoietin. Darbepoetin alfa is effective for chemotherapy-induced anemia when administered once weekly at a dose of 2.25 mug/kg, as shown in two large phase III placebo-controlled trials in patients with solid tumors and hematological malignancies. Furthermore, it was safe and well tolerated. More recently attention has been focused on optimizing Darbepoetin alfa therapy. Front-loaded dosing was explored to accelerate the hemoglobin (Hb) response and effect on QoL, but this idea could not be confirmed in a large phase III study. Based on the prolonged half-life of Darbepoetin alfa, administration every 3 weeks was appealing. In a large phase III trial, noninferiority of administration of 500 mug every 3 weeks compared with the weekly dosing could be confirmed, both in terms of reduction of red blood cell transfusion, Hb parameters, and QoL. This schedule is very convenient for patients and caregivers as it allows synchronization of erythropoietic therapy and common chemotherapy schedules. Questions for future study are the optimal iron supplementation strategy and the effect of Darbepoetin alfa on outcome. This article reviews the clinical development of Darbepoetin alfa with emphasis on recent data.

Epoetin alfa treatment for patients with chemotherapy-induced anemia

Anemia (hemoglobin [Hb] < 12 g/dL) is a frequent and debilitating complication in the treatment of cancer. The negative effects of anemia include impairment of organ systems, disruption of important aspects of patient quality of life, and potential interference with completion and outcomes of cancer chemotherapy. Guidelines issued by the National Comprehensive Cancer Network and the American Society of Hematology/American Society of Clinical Oncology jointly suggest that anemia in patients with cancer be managed by restoring Hb levels to approximately 12 g/dL, thereby minimizing transfusion requirements and resolving clinical symptoms associated with anemia. Recombinant human erythropoietin (epoetin alfa) administered 150 U/kg 3 times weekly or 40,000 U once weekly has been shown in randomized, double-blind, placebo-controlled trials and large, open-label, nonrandomized, community-based studies to effectively and safely correct anemia in patients with cancer undergoing chemotherapy. Several clinical trials support that treatment with epoetin alfa results in quality of life benefits that significantly correlate with Hb increases. Areas currently being investigated with epoetin alfa in the chemotherapy setting include the following: extended dosing regimens beyond the Food and Drug Administration-approved 3-times-weekly and once-weekly dosing regimens, early intervention for mild anemia, effects on treatment outcomes and survival, and optimal administration of concurrent iron supplementation.

Ten years of meta-analyses on erythropoiesis-stimulating agents in cancer patients

BACKGROUND

Since erythropoiesis-stimulating agents (ESAs) were licensed in 1993, more than 70 randomized controlled trials and more than 20 meta-analyses and systematic reviews on their effectiveness were conducted. Here, we present a systematic review on the meta-analyses of trials evaluating ESAs in cancer patients.

METHODS

We included all published meta-analyses of at least five randomized controlled trials that evaluated the effects of ESAs versus control in patients with any type of cancer or myelodysplastic syndrome.

RESULTS

We included a total of 23 systematic reviews and meta-analyses (16 literature based and 7 based on individual patient data (IPD)) that assessed several outcomes. All 12 meta-analyses reporting on transfusion risks demonstrated that ESAs significantly reduce the risk of transfusions. Eleven meta-analyses (nine based on published data and two on IPD) evaluated thrombovascular events. An increased risk of thrombovascular events was observed in all but two meta-analyses (relative risks (RRs) ranging from 1.57 to 1.69). However, potential reporting and publication bias as well as detection bias call for a cautious interpretation of these results. Survival and mortality were evaluated in 18 meta-analyses, with the observed effect changing over time. While meta-analyses on studies conducted before 2002 showed beneficial effects of ESAs on survival, contrary results, i.e. worsened survival, was seen in meta-analyses including more recent studies.

DISCUSSION

The results from several meta-analyses show that ESAs in cancer patients reduce the risk for red blood cell transfusions and increase the risk for thrombovascular events and mortality. The effect of ESAs on mortality risk in patients receiving chemotherapy remains unclear. In clinical practice, the benefits and risks of ESAs should be carefully considered and decisions should be made based on each patient's situation and preferences.

Erythropoiesis-stimulating agents in oncology: a study-level meta-analysis of survival and other safety outcomes

BACKGROUND: Cancer patients often develop the potentially debilitating condition of anaemia. Numerous controlled studies indicate that erythropoiesis-stimulating agents (ESAs) can raise haemoglobin levels and reduce transfusion requirements in anaemic cancer patients receiving chemotherapy. To evaluate recent safety concerns regarding ESAs, we carried out a meta-analysis of controlled ESA oncology trials to examine whether ESA use affects survival, disease progression and risk of venous-thromboembolic events.

METHODS: This meta-analysis included studies from the 2006 Cochrane meta-analysis, studies published/updated since the 2006 Cochrane report, and unpublished trial data from Amgen and Centocor Ortho Biotech. The 60 studies analysed (15 323 patients) were conducted in the settings of chemotherapy/radiochemotherapy, radiotherapy only treatment or anaemia of cancer. Data were summarised using odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS: Results indicated that ESA use did not significantly affect mortality (60 studies: OR=1.06; 95% CI: 0.97–1.15) or disease progression (26 studies: OR=1.01; 95% CI: 0.90–1.14), but increased the risk for venous-thromoboembolic events (44 studies: OR=1.48; 95% CI: 1.28–1.72).

CONCLUSION: Though this meta-analysis showed no significant effect of ESAs on survival or disease progression, prospectively designed, future randomised clinical trials will further examine the safety and efficacy of ESAs when used according to the revised labelling information.

Update on the use of erythropoiesis-stimulating agents (ESAs) for the management of anemia of multiple myeloma and lymphoma

Anemia is a common side-effect of patients with multiple myeloma (MM) and lymphoma. The etiology is complex, but the main cause is the underlying mechanism of anemia of chronic disease, which is characterized among others, by impairment of iron metabolism and consequently iron restricted erythropoiesis (IRE), resulting from the up-regulation of the iron distributing regulator, hepcidin. Erythopoiesis-stimulating agents (ESAs) have been the standard of care since early 90's offering high response rates and improving the quality of life of the patients. However, the role of ESAs in the treatment of cancer-related anemia has been questioned recently, due to the growing evidence which support that ESAs may be associated with increased risk for thrombosis and may have a detrimental impact on patients' survival. Under the light of the recent considerations, the place of ESAs in the management of cancer-related anemia has been reassigned. Regarding the management of anemia in MM or lymphoma, the updated American Society of Clinical Oncology/American Society of Hematology (ASCO/ASH) 2007 clinical practice guidelines on the use of ESAs in cancer-related anemia, recommended that ESAs should be preferably omitted in patients planned to receive chemotherapy and applied in case that anemia does not improve over treatment. The quest for reliable predictors for response to ESAs and for indicators of IRE which plays a major etiological role for the development of anemia of cancer still remains an open issue. In the current review we present an update on ESAs use in anemia of MM and lymphoma.

Darbepoetin alfa in the treatment of chemotherapy-induced anaemia

BACKGROUND

Darbepoetin alfa is an erythropoiesis-stimulating agent (ESA), with a longer half-life than previous recombinant human erythropoietins. After its initial development for anaemia due to renal insufficiency, an extensive clinical trial program has defined its role in cancer patients.

OBJECTIVE/METHODS

Review of the initial registration studies, further development and recent progress, guidelines for use in clinical practice (EORTC, ASCO/ASH), and specific focus on recent safety concerns.

RESULTS

Darbepoetin alfa significantly decreases the number of red blood cell transfusions in patients with chemotherapy-induced anaemia, and has been shown to improve health-related quality of life in several studies. The prolonged half-life allows a prolonged dosing interval. Administration every three weeks, a suitable schedule to synchronise with day 1 of many chemotherapy regimens, is as efficient as the initially registered weekly administration. Recent data strongly suggest that the addition of intravenous iron improves haemoglobin response rates. The use of these agents in clinical practice has to be according to the guidelines. Recent safety data reported a negative effect on survival when ESAs were used to treat anaemia that was either not chemotherapy related, or when used to maintain high levels of haemoglobin and prevent anaemia. All of these studies were not in accordance with existing guidelines, while safety data from clinical trials using ESAs according to the guidelines remain reassuring.

CONCLUSION

Darbepoetin alfa has a well defined place in the treatment of chemotherapy-induced anaemia, and is safe when used in line with existing guidelines. Recent safety signals on cancer outcomes in studies not in accordance with these guidelines illustrate the need for further research into the complex interaction between anaemia and tumour hypoxia in cancer patients.

Biological functions and therapeutic use of erythropoiesis-stimulating agents: perplexities and perspectives

Randomized clinical studies, carried out in patients with haematological malignancies and with solid tumours, have consistently demonstrated that treatment with recombinant human erythropoietin (Epo) increases haemoglobin levels, reduces blood transfusion requirements, and improves the quality of life. In addition, identification of erythropoietin receptor (EpoR) expression on many types of non-erythroid and cancer cells has spurred an interest in the extra-haematological activities of Epo itself and other erythropoiesis-stimulating agents (ESAs). Epo and its derivatives have emerged as major tissue-protective cytokines in ischaemic and degenerative damage of cardiovascular, neurological and renal diseases, while their angiogenetic and immunomodulatory properties indicate that their therapeutic potential may extend well beyond erythropoiesis alone. Both preclinical and clinical data, however, have suggested that they may contribute to tumour progression and prejudice survival when administered to anaemic cancer patients, though the results are equivocal and the assumed mechanisms by which tumour growth could be promoted are not fully understood. While these findings offer new perspectives, they nonetheless demand caution in the employment of ESAs. Further, well-designed experimental and clinical studies are warranted.

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.

Economic evaluation in Sweden of epoetin beta with intravenous iron supplementation in anaemic patients with lymphoproliferative malignancies not receiving chemotherapy

BACKGROUND AND OBJECTIVE

Functional iron deficiency is one reason for lack of response to erythropoietin treatment. Concomitant intravenous (IV) iron supplementation has the potential to improve response to erythropoietin, allowing a decrease in erythropoietin dose requirements. In a recent study of anaemic, iron-replete patients with lymphoproliferative malignancies (Leukemia, 21, 2007, 627), the haemoglobin (Hb) increase and response rate were significantly greater in patients receiving epoetin beta with concomitant IV iron compared with patients receiving epoetin beta without IV iron (P < 0.05). The present analysis aimed to investigate whether a combination of epoetin beta and IV iron is cost-effective compared with epoetin beta without IV iron.

METHODS

This analysis was performed from a Swedish societal perspective as a within-trial evaluation of overall costs (based on differences in drug costs and resource use between groups) and effect (differences in Hb increases) during 16 weeks' treatment with epoetin beta with or without concomitant IV iron.

RESULTS AND DISCUSSION

There was an improved response to epoetin beta with IV iron therapy and an almost 2-fold greater increase in Hb levels. Overall mean cost per patient in the epoetin beta with IV iron group was euro5558 and in the epoetin beta without IV iron group was euro6228. Thus, treatment with epoetin beta with IV iron resulted in overall cost savings of about 11% compared with epoetin beta without iron, mainly due to reduced erythropoietin dosages.

CONCLUSION

Epoetin beta with concomitant IV iron in anaemic patients with lymphoproliferative malignancies not receiving chemotherapy resulted in better outcomes at lower cost compared with epoetin beta without iron. This suggests that epoetin beta with IV iron is a dominant therapy from a Swedish perspective.

Effect of Once-Weekly Epoetin Beta on Survival in Patients With Metastatic Breast Cancer Receiving Anthracycline- and/or Taxane-Based Chemotherapy: Results of the Breast Cancer—Anemia and the Value of Erythropoietin (BRAVE) Study

Purpose

The Breast Cancer—Anemia and the Value of Erythropoietin (BRAVE) study evaluated whether epoetin beta would improve survival in patients with metastatic breast cancer (MBC).

Patients and Methods

BRAVE was an open-label, randomized, multicenter study in patients with MBC treated with anthracycline- and/or taxane-based chemotherapy. Patients (hemoglobin [Hb] < 12.9 g/dL) were randomly assigned (1:1) to epoetin beta 30,000 U subcutaneously once weekly or control for 24 weeks. The primary efficacy variable was overall survival. Secondary efficacy outcomes included progression-free survival, transfusion- and severe anemia–free survival, Hb response, safety, and quality of life (QoL).

Results

After 18 months of follow-up, 62 (27%) of 231 patients survived with epoetin beta therapy and 63 (27%) of 232 with control. No difference was detected in overall survival (hazard ratio [HR] = 1.07; 95% CI, 0.87 to 1.33, P = .522) or progression-free survival (HR = 1.07; 95% CI, 0.89 to 1.30, P = .448). There was a statistically significant benefit on transfusion- and severe anemia–free survival compared with control (HR = 0.59; P = .0097). Median Hb level increased with epoetin beta (11.7 g/dL at baseline to 13.3 g/dL at 24 weeks) but did not change with control (11.5 v 11.4 g/dL). Patients receiving epoetin beta experienced more thromboembolic events (TEEs) compared with controls (13% v 6%; P = .012) with no difference in serious TEEs (4% v 3%). Epoetin beta did not significantly improve QoL in this study where patients had a high baseline Hb value.

Conclusion

In patients with MBC receiving chemotherapy and initial Hb less than 12.9 g/dL, epoetin beta increased Hb. No difference was detected in overall survival. Because of its superiority design, this study cannot, however, exclude clinically important differences in survival with absolute certainty.

Darbepoetin alfa for chemotherapy-induced anemia: evolution to extended dosing intervals

Anemia is a frequent problem in cancer patients, especially in those treated with chemotherapy, and has an important negative impact on quality of life. Red blood cell transfusions provide clear but rather temporary comfort. The development of erythropoietic stimulating agents (ESAs) led to a more durable anemia treatment. Darbepoetin alpha is a unique ESA with a long plasma half life, thereby suitable for administration with different dosing intervals. Apart from administration every week, darbepoetin alpha also proved to be efficient in reducing red blood cell transfusion rates and in improving health-related quality of life when administered at a dose of 500 microg once every 3 weeks. This is a convenient therapy schedule because it can be synchronized with the chemotherapy cycle in many patients. Recently, concerns have been raised about the long-term safety of ESAs, more specifically about their effect on survival. Available data must be interpreted with caution, but at present there is no clear evidence to support a negative effect on outcome with darbepoetin alpha therapy when used according to the guidelines for treatment of chemotherapy-induced anemia. Further studies focusing on survival as the primary end point are ongoing.

Erythropoietin therapy and cancer related anaemia: updated Swedish recommendations

Due to concerns related to treatment with erythropoietin (EPO) and possible negative effects on tumour control, a workshop was organised by the Medical Products Agency of Sweden with the aim to revise national treatment guidelines if needed. In patients with solid tumours, conflicting results have been reported with respect to tumour control and survival. Until further notice it is therefore recommended that EPO should be used restrictively in the treatment of patients with cancer and that the anticipated improvement in quality of life should be evaluated against potential risks.

Erythropoietic therapy for the treatment of anemia in patients with cancer: a valuable clinical and economic option

BACKGROUND

Healthcare organizations must evaluate the cost effectiveness of the alternative therapies that are available to treat anemia and improve quality of life (QoL) of patients with cancer, that is, erythropoietic protein therapy and blood transfusion.

METHODS

Pharmacoeconomic studies that evaluated the cost of not treating anemia or treating with transfusion or erythropoietic protein therapy were reviewed and compared. Studies of individual erythropoietic proteins (epoetin alfa, epoetin beta or darbepoetin alfa) were also assessed. As no prospective trials have compared the erythropoietic proteins, retrospective studies and the results of separate trials were analyzed. The database searched for this review was PubMed (open date to August 2006). Recent conference abstracts were also searched (2003-July 2006).

RESULTS

There is a high cost associated with anemia in cancer patients. Treatment of anemia is likely to lead to increased hemoglobin (Hb) levels and improved QoL as principal outcomes. Therefore, in assessing erythropoietic protein versus transfusion, it is more appropriate to use Hb or QoL as endpoint rather than quality adjusted life year. Studies with the former approach showed that erythropoietic protein therapy is more cost effective than transfusion. Also, its cost effectiveness should be improved with the use of evidence-based guidelines for patient selection and more tailored utilization. Increasing evidence suggests there might be differences among the erythropoietic proteins in terms of response rate, speed of response, and need for dose escalation.

CONCLUSION

Significant costs are incurred when anemia in cancer is not treated. Erythropoietic protein therapy is more cost effective than blood transfusion for the treatment of cancer-related anemia. Transfusion should be reserved for patients with poor responses to erythropoietic protein or for the emergency setting, when rapid improvement in Hb is required.

Preclinical studies of erythropoietin receptor expression in tumour cells: Impact on clinical use of erythropoietic proteins to correct cancer-related anaemia

In vitro and animal model studies have shown erythropoietin receptor (Epo-R) mRNA and/or protein may be present in a range of human tumours and cancer cell lines, and erythropoiesis-stimulating agents (ESAs) have been reported to have tumour cell growth-modulating effects. Following a review of the literature, we conclude that considerations must be made when interpreting data from the preclinical studies. First, supraphysiological doses of ESAs were usually used. Second, there are no well validated, commercially available antibodies for identifying the presence and functionality of Epo-R at the protein level, either intracellularly or on the cell surface. Data from previous studies that used antibodies only for Epo-R detection must therefore be interpreted with caution. Together with diverging results in the literature, these methodological limitations indicate that findings from preclinical studies must not be over-translated in terms of their clinical relevance to patients with cancer.

Guidelines and Recommendations for the Management of Anaemia in Patients with Lymphoid Malignancies

Patients with lymphoid malignancies frequently require repetitive and intensive anticancer treatments to induce and maintain disease remission. Anaemia (haemoglobin [Hb] <12 g/dL) is a common and debilitating problem associated with both the malignancy itself and its treatment burden. Anaemia negatively impacts on all aspects of patient quality of life (QOL) and treatment outcomes and survival, particularly in this disease setting. Widely acknowledged goals of anaemia treatment include Hb correction to approximately 12 g/dL, reduction in transfusion requirements and optimisation of patient QOL. Since the introduction of recombinant human erythropoietic therapy, transfusion (once the only anaemia treatment option available) is now primarily reserved for non-responders or those with severe or life-threatening anaemia. Data from randomised, double-blind, placebo-controlled studies, and large, non-randomised, open-label, community-based studies, along with almost 15 years of practical experience, support the assertion that epoetin alfa administered at a dosage of 150-300 U/kg three times weekly or 40,000-60,000U once weekly, both of which are US FDA-approved dose administration schedules, can effectively and safely achieve anaemia treatment goals for the majority of patients with lymphoid malignancies. Data and practical experience collected over the last 5 years on another erythropoietic agent with a slightly longer half-life but lower binding affinity, darbepoetin alfa, show that this agent when administered according to the FDA-approved dose administration schedules (2.25-4.5 microg/kg once weekly or 500microg once every 3 weeks) or according to a commonly-administered dose in clinical practice (3.0-5.0 microg/kg once every 2 weeks) can also effectively and safely correct anaemia, reduce transfusion requirements and improve QOL in many patients with lymphoid malignancies. One comparative head-to-head trial suggested that epoetin alfa might be superior to darbepoetin alfa in anaemic cancer patients receiving chemotherapy with respect to timing and magnitude of Hb correction, although further study is necessary, especially concerning optimal dose administration. Alternative dose administration schedules, such as epoetin alfa 80,000U every 2 weeks from initiation or 80,000U every 3 weeks following initiation with once weekly administration and darbepoetin alfa 4.5 microg/kg every 3 weeks following initiation with once weekly administration, are being actively investigated with the goal of increased flexibility for patients and healthcare providers. The treatment of anaemia in patients with lymphoid malignancies is an important part of overall disease management, as evidenced by continuous investigation of existing erythropoietic agents and new agents. Although treatment guidelines issued by organisations such as the National Comprehensive Cancer Network (NCCN) and American Society of Hematology (ASH)/American Society of Clinical Oncology (ASCO) suggest intervention with erythropoietic therapy when Hb falls below 10-11 g/dL or based on clinical symptoms, data suggest that anaemia is vastly under-recognised and under-treated. Clearly, an update on the definition, identification and optimal management of anaemia in patients with lymphoid malignancies is warranted.

EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer: 2006 update

Anaemia is frequently diagnosed in patients with cancer, and may have a detrimental effect on quality of life (QoL). We previously conducted a systematic literature review (1996-2003) to produce evidence-based guidelines on the use of erythropoietic proteins in anaemic patients with cancer.[Bokemeyer C, Aapro MS, Courdi A, et al. EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer. Eur J Cancer 2004;40:2201-2216.] We report here an update to these guidelines, including literature published through to November 2005. The results of this updated systematic literature review have enabled us to refine our guidelines based on the full body of data currently available. Level I evidence exists for a positive impact of erythropoietic proteins on haemoglobin (Hb) levels when administered to patients with chemotherapy-induced anaemia or anaemia of chronic disease, when used to prevent cancer anaemia, and in patients undergoing cancer surgery. The addition of further Level I studies confirms our recommendation that in cancer patients receiving chemotherapy and/or radiotherapy, treatment with erythropoietic proteins should be initiated at a Hb level of 9-11 g/dL based on anaemia-related symptoms rather than a fixed Hb concentration. Early intervention with erythropoietic proteins may be considered in asymptomatic anaemic patients with Hb levels 11.9 g/dL provided that individual factors like intensity and expected duration of chemotherapy are considered. Patients whose Hb level is below 9 g/dL should primarily be evaluated for need of transfusions potentially followed by the application of erythropoietic proteins. We do not recommend the prophylactic use of erythropoietic proteins to prevent anaemia in patients undergoing chemotherapy or radiotherapy who have normal Hb levels at the start of treatment, as the literature has not shown a benefit with this approach. The addition of further supporting studies confirms our recommendation that the target Hb concentration following treatment with erythropoietic proteins should be 12-13 g/dL. Once this level is achieved, maintenance doses should be titrated individually. There is Level I evidence that dosing of erythropoietic proteins less frequently than three times per week is efficacious when used to treat chemotherapy-induced anaemia or prevent cancer anaemia, with studies supporting the use of epoetin alfa and epoetin beta weekly and darbepoetin alfa given every week or every 3 weeks. We do not recommend the use of higher than standard initial doses of erythropoietic proteins with the aim of producing higher haematological responses, due to the limited body of evidence available. There is Level I evidence that, within reasonable limits of body weight, fixed doses of erythropoietic proteins can be used to treat patients with chemotherapy-induced anaemia. This analysis confirms that there are no baseline predictive factors of response to erythropoietic proteins that can be routinely used in clinical practice if functional iron deficiency or vitamin deficiency is ruled out; a low serum erythropoietin (EPO) level (only in haematological malignancies) appears to be the only predictive factor to be verified in Level I studies. Further studies are needed to investigate the value of hepcidin, c-reactive protein, and other measures as predictive factors. In these updated guidelines, we explored a new question of whether oral or intravenous iron supplementation increases the response rate to erythropoietic proteins. We found no evidence of increased response with the addition of oral iron supplementation, but there is Level II evidence of improved response to erythropoietic proteins with the addition of intravenous iron. However, the doses and schedules for intravenous iron supplementation are not yet well defined, and further studies in this area are warranted. The two major goals of erythropoietic protein therapy are prevention or elimination of transfusions and improvement of QoL. The total body of evidence shows that red blood cell (RBC) transfusion requirements are reduced following treatment with erythropoietic proteins. This analysis also confirms that QoL is significantly improved in patients with chemotherapy-induced anaemia and in those with anaemia of chronic disease following erythropoietic protein therapy, with more robust evidence now available that QoL was improved in studies investigating early intervention in cases of chemotherapy- or radiotherapy-induced anaemia. There is only indirect evidence that patients with chemotherapy-induced anaemia or anaemia of chronic disease initially classified as non-responders to standard doses proceed to respond to treatment following a dose increase. None of the studies addressed the question in a prospective, randomised fashion, and so the Taskforce does not recommend dose escalation as a general approach in all patients who are not responding. There is still insufficient data to determine the effect on survival following treatment with erythropoietic proteins in conjunction with chemotherapy or radiotherapy. Our analysis of survival endpoints in studies involving patients receiving radio(chemo)therapy found that most studies were inconclusive, with no clear link between the use of erythropoietic proteins and survival. Likewise, we found no clear link between erythropoietic therapy and other endpoints such as local tumour control, time to progression, and progression-free survival. There is no evidence that pure red cell aplasia occurs in cancer patients following treatment with erythropoietic proteins, and the fear of this condition developing should not lead to erythropoietic proteins being withheld in patients with cancer. There is Level I evidence that the risk of thromboembolic events and hypertension are slightly elevated in patients with chemotherapy-induced anaemia receiving erythropoietic proteins. Additional trials are warranted, especially to define the optimal doses and schedules of intravenous iron supplementation during erythropoietic therapy. While our review did not address cost benefit evaluations in detail, the consensus is that studies taking into account all real determinants of cost and benefit need to be performed prospectively.

Effect of treatment with epoetin beta on short-term tumour progression and survival in anaemic patients with cancer: A meta-analysis

To assess the early effect of epoetin beta on survival and tumour progression in anaemic patients with cancer, data were pooled from nine randomised clinical trials comparing epoetin beta with placebo or standard care. Studies were not primarily designed to assess these end points. Follow-up was for treatment duration plus 4 weeks following therapy completion. All adverse events (AEs) were retrospectively reviewed blinded, for progression. Thromboembolic events were also assessed. Data analysis involved standard statistical tests. Overall, 1413 patients were included (epoetin beta, n=800; control, n=613; 56% haematological, and 44% solid). Median initial epoetin beta dose was 30 000 IU/week. Overall survival during months 0–6 was similar with epoetin beta and control (0.31 vs 0.32 deaths/patient-year). No increased mortality risk was seen with epoetin beta (relative risk (RR) 0.97, 95% CI: 0.69, 1.36; P=0.87). There was a significantly reduced risk of rapidly progressive disease for epoetin beta (RR 0.78, 95% CI: 0.62, 0.99; P=0.042). Epoetin beta was associated with a slightly higher frequency of thromboembolic events vs control (5.9% vs 4.2% of patients) but thromboembolic-related mortality was identical in both groups (1.1%). Epoetin beta provided a slight beneficial effect on tumour progression and did not impact on early survival or thromboembolic-related mortality.

New agents that stimulate erythropoiesis

Recombinant human erythropoietin (rhEpo) has proven to be remarkably safe and effective for treatment of anemias, primarily those secondary to renal disease and malignancy. Despite the worldwide use of rhEpo, concerns about its cost, the need for frequent parenteral administration, and the development of anti-Epo antibodies have prompted development of improved agents to stimulate erythropoiesis. Three strategies appear to be particularly promising. The half-life of Epo in the circulation can be prolonged by the addition of N-linked carbohydrate groups, by formation of adducts with polyethylene glycol, and by preparation of Epo multimers. Second, mimetic peptides can effectively trigger signal transduction at the Epo receptor, thereby boosting red-cell production. Finally, the hypoxia inducible transcription factor (HIF) can be pharmacologically induced by oral agents, resulting in enhanced expression not only of endogenous Epo but also of other genes important in the regulation of erythropoiesis.

Current and future options for the treatment of chemotherapy-induced anaemia

Chemotherapy-induced anaemia (CIA) is a significant source of morbidity in patients receiving treatment for cancer. There are three products currently available for the treatment of CIA: epoetin alfa, epoetin beta and darbepoetin alfa. Several organisations have published recommendations for the use of these agents. Several randomised, controlled trials have been conducted comparing the most popular dosing regimens of epoetin alfa and darbepoetin alfa, with conflicting results. Information regarding survival and adverse event data related to these agents continues to create debate. This review considers four new agents that are under development for the treatment of CIA.

Cancer-related anaemia management in the 21st century

Anaemia has a high prevalence and incidence in patients with cancer receiving chemotherapy and is associated with a range of symptoms, including fatigue, drowsiness, depression, dyspnoea, tachycardia and dizziness. Fatigue, in particular, exerts a considerable impact on patient quality of life, affecting 80-100% of patients receiving chemotherapy and, potentially, delaying treatment. Until recently, red blood cell transfusions were the mainstay of treatment for cancer-related anaemia. While effective in ameliorating symptoms, transfusions are associated with short-lived benefits and a risk of infections and disease transmission. The development of the erythropoiesis-stimulating agent (ESA), recombinant human erythropoietin (rHuEPO), resulted in a 50% reduction in the number of transfusions required in anaemic cancer patients receiving chemotherapy. The subsequently introduced rHuEPO analogue, darbepoetin alfa, stimulates erythropoiesis by the same mechanism as rHuEPO but is associated with a prolonged serum half-life, allowing extended dosing intervals and less frequent administration. With the introduction of a number of ESAs and a growing wealth of data concerning their indications, dosing regimens and safety, European cancer organizations have recently developed guidelines for their effective use in clinical practice.

Erythropoietin fails to interfere with the antiproliferative and cytotoxic effects of antitumor drugs

PURPOSE

Erythropoietin (EPO) therapy is widely used for the prevention and treatment of anemia resulting from cancer chemotherapy. Native EPO regulates erythropoiesis, at least in part, by protecting erythroid progenitor cells from apoptotic cell death. The recent discovery of the EPO receptor (EPOR) on cancer cells raises the concern that EPO therapy might stimulate tumor growth and/or protect cancer cells from drug-induced apoptosis. Therefore, the capacity of EPO to interfere with the effects of conventional chemotherapeutic drugs on proliferation, apoptosis, and the induction of senescence was investigated in MCF-7 and MDA-MB231 breast tumor cells, which express the EPOR as well as in F-MEL erythroleukemia cells.

EXPERIMENTAL DESIGN

Breast cancer cells and F-MEL leukemic cells were cultured in the presence or absence of EPO and then exposed to antitumor drugs. Cell proliferation was assessed by a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction assay 72 hours after drug exposure. Cytotoxicity was monitored by clonogenic survival. Apoptosis was evaluated either by the terminal deoxyribonucleotide transferase-mediated nick-end labeling assay or fluorescence-activated cell sorting analysis, and senescence was monitored by beta-galactosidase staining. EPO signaling was assessed by monitoring the phosphorylation/activation of specific signaling proteins.

RESULTS

EPO failed to stimulate the proliferation of MCF-7 or MDA-MB231 breast tumor cells or F-MEL leukemic cells. EPO treatment also failed to interfere with the antiproliferative and/or cytotoxic effects of Adriamycin, Taxol, and tamoxifen in breast tumor cells (or of cytarabine and daunorubicin in F-MEL cells). EPO failed to prevent apoptosis induced by Taxol or senescence induced by Adriamycin in MCF-7 cells. EPO stimulated the activation of extracellular signal-regulated kinase, p38, and c-Jun-NH(2)-kinase in MCF-7 cells but did not activate Akt or signal transducers and activators of transcription 5 (STAT5). EPO failed to activate any of these signaling pathways in MDA-MB231 cells. Cytarabine and daunorubicin interfered with EPO signaling in F-MEL cells.

CONCLUSIONS

These findings suggest that EPO is unlikely to directly counteract the effectiveness of cancer chemotherapeutic drugs. This may be a consequence of either ineffective signaling through the EPOR or drug-mediated suppression of EPO signaling.

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.