Darbepoetin alfa given every 1 or 2 weeks alleviates anaemia associated with cancer chemotherapy

Cresp®: transforming the landscape of chemotherapy-induced anemia - a comprehensive retrospective real-world analysis in 523 Indian patients

Introduction

Anemia, a frequently encountered issue among cancer patients undergoing chemotherapy, is regrettably underappreciated despite its prevalence and profound impact on their well-being. Chemotherapy-induced anemia (CIA) diminishes the quality of life, causing fatigue, breathlessness, and a decline in the performance status. However, correcting anemia can lead to notable improvements in these parameters. Notably, darbepoetin alpha (DA) has shown efficacy in addressing anemia in this context. This real-world study aims to evaluate the efficacy of DA in the treatment of CIA among Indian cancer patients.

Methods

This single-center retrospective study assessed the effectiveness of DA in treating CIA among advanced/metastatic solid tumor patients on palliative myelosuppressive therapy. The study measured the change in hemoglobin levels after DA administration as the primary outcome, with secondary outcomes including impact on blood transfusion dependence, changes in anemia-related symptoms, and occurrence of adverse events.

Results

A total of 523 patients, with a median age of 55, were included in the study. Patients were categorized based on cancer site, type of chemotherapy, response to therapy, and DA doses. A significant mean increase of 2.28 gm/dl in hemoglobin (Hb) levels from baseline to post-DA administration was observed (8.56±0.45 to 10.84±0.92; 26.6%; P<.001). Each sub-group revealed a significant enhancement of mean hemoglobin from baseline to the end of treatment. Significant improvements were noted from baseline in fatigue, and dyspnea. Adverse drug reactions included hypertension (5.4%), deep vein thrombosis (2.9%), and arrhythmias (0.8%).

Discussion

DA demonstrates impressive efficacy and safety in managing CIA, leading to substantial improvements in mean hemoglobin levels in palliative setting. This has the potential to reduce the need for blood transfusions and enhance the quality of life for patients.

Literature Review of Fatigue Scales and Association with Clinically Meaningful Improvements in Outcomes Among Patients With and Without Paroxysmal Nocturnal Hemoglobinuria

Introduction

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by anemia and debilitating fatigue. Limited evidence characterizes the association between hemoglobin, an indicator of anemia and disease activity, and patient-reported fatigue scales. This review identifies benchmarks for clinically meaningful improvements in patients with and without PNH.

Methods

MEDLINE, Embase, Cochrane, and PsycINFO databases were searched along with Google Scholar to identify publications for patients with and without PNH. Full-text articles and conference abstracts of clinical trials or observational studies that examined patient-reported fatigue or associations between fatigue and hemoglobin were included.

Results

Fourteen publications were included in this study. Four clinical trials conducted in patients with PNH reported that patients achieved and sustained clinically meaningful improvements in fatigue. However, these studies did not examine the association between fatigue and hemoglobin. Ten studies conducted in patients with cancer and anemia (with or without chemotherapy) demonstrated an association between increased hemoglobin and improvements in fatigue (P < 0.05). The greatest incremental gain in fatigue improvement was observed when hemoglobin increased from 11 to 12 g/dL.

Conclusion

Evidence among patients with cancer without PNH demonstrates that increased hemoglobin levels are associated with clinically significant improvements in fatigue. Future studies should validate this relationship among patients with PNH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02111-7.

Application of Pharmacokinetic-Pharmacodynamic Modeling in Drug Delivery: Development and Challenges

With the advancement of technology, drug delivery systems and molecules with more complex architecture are developed. As a result, the drug absorption and disposition processes after administration of these drug delivery systems and engineered molecules become exceedingly complex. As the pharmacokinetic and pharmacodynamic (PK-PD) modeling allows for the separation of the drug-, carrier- and pharmacological system-specific parameters, it has been widely used to improve understanding of the in vivo behavior of these complex delivery systems and help their development. In this review, we summarized the basic PK-PD modeling theory in drug delivery and demonstrated how it had been applied to help the development of new delivery systems and modified large molecules. The linkage between PK and PD was highlighted. In particular, we exemplified the application of PK-PD modeling in the development of extended-release formulations, liposomal drugs, modified proteins, and antibody-drug conjugates. Furthermore, the model-based simulation using primary PD models for direct and indirect PD responses was conducted to explain the assertion of hypothetical minimal effective concentration or threshold in the exposure-response relationship of many drugs and its misconception. The limitations and challenges of the mechanism-based PK-PD model were also discussed.

Transfusion practice patterns in patients with anemia receiving myelosuppressive chemotherapy for nonmyeloid cancer: results from a prospective observational study

PURPOSE

The decision to prescribe packed red blood cell (PRBC) transfusions in patients with chemotherapy-induced anemia (CIA) includes assessment of clinical features such as the patient's cancer type and treatment regimen, severity of anemia symptoms, and presence of comorbidities. We examined contemporary transfusion practices in patients with nonmyeloid cancer and CIA.

METHODS

Key inclusion criteria were age ≥ 18 years with nonmyeloid cancer, receiving first/second-line myelosuppressive chemotherapy, baseline hemoglobin (Hb) ≤ 10.0 g/dL, and planned to receive ≥ 1 PRBC transfusions. Exclusion criteria were receipt of erythropoiesis-stimulating agents within 8 weeks of screening and/or chronic renal insufficiency. Data were collected from patients' medical records, laboratory values, and physician/provider questionnaires. Proportion of patients for each clinical consideration leading to a decision to prescribe a PRBC transfusion and 95% exact binomial confidence intervals were determined.

RESULTS

The study enrolled 154 patients at 18 sites in USA; 147 (95.5%) received a PRBC transfusion. Fatigue was the most common symptom affecting the decision to prescribe a PRBC transfusion (101 [69.2%] patients). Of the three reasons selected as primary considerations for prescribing a PRBC transfusion, anemia symptoms (106 [72.1%] patients) was the most frequently reported, followed by Hb value (37 [25.2%] patients) and medical history (4 [2.7%] patients).

CONCLUSIONS

In this study, the primary consideration for prescribing a PRBC transfusion was anemia symptoms in 72.1% of patients, with only 25.2% of patients prescribed a transfusion based exclusively on Hb value. Results indicate that clinical judgment and patient symptoms, not just Hb value, were used in decisions to prescribe PRBC transfusions.

Darbepoetin Alfa Administered Once Every Three Weeks for the Treatment of Anemia in Elderly Patients with Non-myeloid Tumors Receiving Chemotherapy

Aims and Background

The present study aims to describe the hematological response to darbepoetin alfa (DA) under daily clinical practice conditions in anemic elderly patients with non-myeloid tumors receiving chemotherapy.

Methods and Study Design

This was a prospective, observational, multicenter study in elderly (≥65 years) patients with non-myeloid cancer receiving DA (500 g every 3 weeks) for chemotherapy-induced anemia (hemoglobin [Hb] level ≤11.0 g/dL).

Results

A total of 102 anemic patients with solid tumors and 51 with hematological malignancies were included in 28 centers in Spain. Mean age (±SD) was 73.4 (±5.8) years, and mean baseline Hb level was 10.0 (±0.8) g/dL. DA was administered for a median of 8 weeks. Of the 115 subjects with a post-baseline Hb value, the percentage of patients who achieved a hematopoietic response (Hb increase ≥2 g/dL or reaching ≥12 g/dL without transfusions in the previous 28 days) was 69.7% (95% CI 56.1% to 83.3%). Functional Assessment of Cancer Therapy-Fatigue subscale scores increased during the study (median change 1.0 [Q1 −5.0, Q3 9.0], P = 0.04). One patient (0.7%) experienced a non-serious adverse reaction (cutaneous rash).

Conclusion

The study results suggest that DA is an effective and well-tolerated therapy for the treatment of chemotherapy-induced anemia in elderly patients.

Management of Cancer Anemia

Anemia complicates the course of disease in about 50% of patients with cancer, and negatively affects their quality of life. A correct approach to therapy should consider all the possible causes and patients need to be treated accordingly. The observation that erythropoietin production is often blunted offers new treatment possibilities. Fifty to 70% of anemic patients respond to rHuEpo, given in a three times or once-a-week schedule. The novel hyperglycosylated protein darbepoetin permits longer intervals between administrations, thanks to its longer half-life, and a once per cycle or once-a-month schedule is a reasonable target. Correction of anemia improves the quality of life, and it has been hypothesized that improvement of cognitive function may derive from a direct effect of Epo on CNS cells. Although anemia is an adverse prognostic factor in cancer, results of recent clinical trials have raised the question whether rHuEpo may favor neoplastic cell proliferation. Results are conflicting at the moment, and further studies are required before arriving at a conclusion. Data available so far do not indicate any negative effect of darbepoetin on the outcome of cancer disease, nor has the production of anti-darbepoetin antibodies or PRCA been reported, a complication observed in less than 200 patients with anemia due to renal insufficiency and treated with rHuEpo alpha.

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.

Association between serum levels of C-reactive protein and response to treatment of chemotherapy-induced anemia in patients with solid tumors: a multicenter, prospective, observational study

Our objective was to determine the association between C-reactive protein (CRP) levels at initiation of anemia treatment and response in solid tumor patients with chemotherapy (CT)-induced anemia. This was a multicenter, prospective, observational study which included adult patients with solid tumor initiating treatment for CT-induced anemia. Data were collected up to 16 weeks, or until premature discontinuation. We included 98 patients (median age 62.5 years, 64 % males, 57 % with ECOG 0-1, 85.7 % at stages III-IV and 54.1 % undergoing palliative CT). Mean (SD) Hb levels at baseline were 10.3 (0.9) g/dL (85.7 % < 11 g/dL) and median (Q1; Q3) CRP was 16.4 mg/L (3.9; 77.8) (68 % ≥ 5 mg/L). A total of 96 % of patients initiated erythropoiesis-stimulating agents (ESA) and iron supplementation; 4 % initiated iron monotherapy. After a median of 85 days, 65 % of patients had Hb ≥ 11 g/dL (in absence of transfusion) (mean change: +0.86 g/dL, 95 % confidence interval (CI) 0.53-1.19). A total of 8 patients required transfusion. A significant correlation (r = -0.39, p = 0.003) was observed between baseline CRP and final Hb levels. In the multivariate linear regression analysis, the independent predictors of higher final Hb levels were a high baseline Hb (adjusted ß = +0.69 g/dL for each g/dL of baseline Hb, 95 % CI 0.17-1.21) and a low log baseline CRP (-0.62 for each log mg/L, 95 %CI -1.22 to -0.02). Our results suggest that, in patients with solid tumors and CT-induced anemia, high CRP levels at treatment initiation predict a poor response to treatment with ESA and iron, independently from anemia severity at therapy initiation and from other patient and disease characteristics.

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.

Hemoglobin Decline in Chemotherapy Patients Prior to and after Policy Changes Affecting Use of Erythropoiesis-Stimulating Agents: 2006 – 2009

OBJECTIVE: Since 2007, the use of erythropoiesis-stimulating agents (ESAs) to treat anemia in cancer patients receiving chemotherapy has been increasingly restricted in the USA. This study assessed hemoglobin (Hb) decline over time among chemotherapy patients. METHODS: Episodes of chemotherapy care were identified in a large US-oncology electronic medical record database; weekly Hb levels were computed in the first 8 weeks. Unadjusted and adjusted proportions of patient-weeks with Hb decline > 1 g/dl (i.e. representing clinically significant decline) within 1 or 2 weeks were analyzed. RESULTS: Between 2006 and 2009, unadjusted proportions of patient-weeks with Hb decline > 1 g/dl increased (1-week, from 12.7% to 14.9%; 2-week, from 19.3% to 26.3%). Adjusted 1-week proportions in 2007 were similar to 2006, but increased in 2008 (odds ratio [OR] 1.135; 95% confidence intervals [CI] 1.067, 1.208) and in 2009 (OR 1.235; 95% CI 1.094, 1.395). Adjusted 2-week proportions had the same pattern. CONCLUSIONS: Since restrictions on ESA use were introduced in the USA, more patients have experienced a clinically significant Hb decline after chemotherapy initiation. Initiating anemia therapy at the earliest indicated opportunity may help reduce the risk of such declines.

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.

Effectiveness of darbepoetin alfa in a cohort of oncology patients with chemotherapy-induced anaemia. Relationship between variation in three fatigue-specific quality of life questionnaire scores and change in haemoglobin level

BACKGROUND

Cancer patients with chemotherapy-induced anaemia (CIA) often experience cancer-related fatigue (CRF). Darbepoetin alfa (DA) once every 3 weeks (q3w) is an effective and well tolerated erythropoiesis-stimulating agent. This study evaluated DA effectiveness and psychometric properties of the Functional Assessment of Cancer Therapy Fatigue-Subscale (FACT-F) and the Fatigue Symptom Inventory (FSI) in CIA patients.

METHODS

This was a single-centre, prospective study in 100 patients with solid tumour and moderate to severe CRF (visual analogue scale [VAS-F] ≥ 30 mm) who received DA 500 μg q3w during chemotherapy (CT). Clinical data, VAS-F, FACT-F and FSI scores were collected at the beginning and at the end of CT (EOCT).

RESULTS

Mean age was 62.7 years (SD: 12.1), 53.0% were women, 92.0% had ECOG 0-1 and 64% had stage IV tumours. Mean haemoglobin (Hb) significantly increased from baseline 10.2 g/dl to 11.3 g/dl at EOCT. Sixty-five percent of patients showed haematopoietic response at any study point (Hb ≥ 12 g/dl or an increase of ≥ 2 g/dl from baseline), 77% achieved Hb ≥ 11 g/dl and 7% required blood transfusions from week 5 to EOCT. CRF improvement was demonstrated by significant changes in VAS-F, FACT-F and FSI scores (decreases of 21.54, 3.56 and 12.97 points, respectively). FACT-F and FSI questionnaires showed high internal consistency (Cronbach's alpha of 0.98 and 0.98 for FACT-F and FSI, respectively, at the end of study) and satisfactory intra-class coefficients (FACT-F, r=0.73; FSI, r=0.83). There were significant correlations between scores and Hb changes (FACT-F, r=-0.44; FSI, r=-0.54).

CONCLUSIONS

DA 500 μg q3w showed effectiveness in improving Hb and inducing a clinically significant decrease in CRF of patients with solid tumours undergoing CT. The three instruments, VAS-F, FACT-F and FSI, could be suitable for assessing CRF.

Every-three-week erythropoietic support during chemotherapy for cancer: current status and future issues

Recently, it has been demonstrated that the administration of chemotherapy alters the pharmacology of erythropoietic-stimulating proteins (ESPs), such as endogenous erythropoietin and darbepoetin alfa, with an apparent decrease in clearance and substantial prolongation of half-life. This observation, coupled with the popularity of every-3-week chemotherapy regimens, makes it logical to pursue less-frequent dosing schedules for darbepoetin alfa. Two published studies have demonstrated that darbepoeitin alfa administered at a dose of 6.75 mug/kg or every 3 weeks to anemic patients with cancer is associated with improvements in hemoglobin levels. It has also been shown that dosing on the same day as chemotherapy is as efficacious and safe as dosing asynchronously in patients receiving every-3-week chemotherapy. These studies have increased our understanding of the biology of the interplay between chemotherapy, erythropoiesis, and ESPs and should facilitate the development of increasingly convenient and effective approaches to the treatment of chemotherapy-associated anemia. These insights are reviewed in this article. At the same time, evidence is accumulating that earlier initiation of ESP therapy, before severe anemia and symptoms occur, will be associated with further reduction in transfusion requirements, less patient-reported fatigue, and lower required doses of ESPs. In addition, recently presented trials have reported very important improvements in erythropoietic response to ESPs when patients with chemotherapy-associated anemia are treated with parenteral iron. The early initiation and parenteral iron initiatives pose opportunities and challenges for treatment regimens emerging from our increasing biologic understanding, and these are also reviewed.

Efficacy of Darbepoetin Alfa in the Treatment of Chemotherapy-Induced Anemia in Non-Hodgkin's Lymphoma

BACKGROUND

Patients receiving chemotherapy often experience chemotherapy-induced anemia, which contributes to a significant reduction in their quality of life. This exploratory analysis assessed the efficacy, dosing, and safety of darbepoetin alfa administered every 2 weeks to a subset of patients with non-Hodgkin's lymphoma and chemotherapy-induced anemia who were enrolled in 2 large, multicenter, open-label, community-based studies: the Successful Outcomes in Anemia Research (SOAR) trial and the Study to Understand and Reduce Patients' Anemia Symptom Severity (SURPASS).

PATIENTS AND METHODS

Eligible patients were receiving multicycle chemotherapy and were anemic, with hemoglobin levels </= 11 g/dL. Patients received darbepoetin alfa 3 squareg/kg every 2 weeks (SOAR; n = 114) or 200 squareg every 2 weeks (SURPASS; n = 165). Hemoglobin levels were measured every 2 weeks, and quality of life assessments were recorded at baseline and the end of the study using the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) scale. This analysis includes patients who received >/= 1 dose of darbepoetin alfa.

RESULTS

By week 17, 77% of patients in SOAR (95% confidence interval, 68%-84%) and 82% of patients in SURPASS (95% confidence interval, 76%-88%) exhibited the target hemoglobin range (11-13 g/dL). Both every-2-week dosing regimens reduced the percentage of patients who required >/= 1 red blood cell transfusion by 2.5-fold during each study. Increases in hemoglobin levels were associated with improvements in FACT-F, with similar mean changes in FACT-F scores in both studies: 6.2 points for SOAR and 6.1 points for SURPASS.

CONCLUSION

Darbepoetin alfa administered every 2 weeks in patients with non-Hodgkin's lymphoma and chemotherapy-induced anemia appeared equally effective and well tolerated when given as a weight-based or a fixed dose.

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.

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.

Hemoglobin increase is associated with improved health-related quality of life in patients with cancer not receiving chemotherapy

Anemia is becoming recognized as a substantial problem for patients with cancer who are not receiving chemotherapy. Recently, darbepoetin alfa has been shown to provide significant clinical benefits in this patient population. This analysis assesses the effect of change in hemoglobin levels on health-related quality of life (HRQOL) in these patients. Eligible patients had anemia (hemoglobin </= 11 g/dL), had nonmyeloid malignancy, and had not received cytotoxic chemotherapy or radiation therapy </= 8 weeks before the study. Fatigue and other HRQOL outcomes were measured using the Functional Assessment of Cancer Therapy (FACT) General and Fatigue subscales, the Brief Symptom Inventory depression and anxiety subscales, and numeric rating scales of energy, activity, and overall health. Improvements in hemoglobin were significantly associated with reductions in fatigue (P < 0.001), improvements in functional (P < 0.0001) and physical (P = 0.001) well-being, depression (P = 0.023), anxiety (P = 0.022), and global ratings of energy (P = 0.0004), activity (P = 0.0008), and overall health (P = 0.003). Clinically meaningful improvements in fatigue (defined as an increase in FACT-Fatigue subscale score of >/= 3 points) were significantly (P < 0.05) associated with improvements in functional, physical, and emotional well-being, depression, anxiety, and global ratings of energy, activity, and overall health. In summary, an increase in hemoglobin was associated with a decrease in fatigue in patients with anemia associated with nonmyeloid malignancies who were not receiving chemotherapy.

Assessing the effect of darbepoetin alfa on patient-reported fatigue in chemotherapy-induced anemia in four randomized, placebo-controlled clinical trials

PURPOSE

This analysis examined the effects of darbepoetin alfa on hemoglobin and fatigue outcomes in patients with cancer using latent growth curve modeling (LGM).

METHODS

Data from 4 clinical trials of darbepoetin alfa in lung cancer (2 studies; n = 547; n = 288), lymphoproliferative malignancies (n = 339), and non-myeloid malignancies (n = 320) were analyzed separately. Fatigue was assessed using the FACT-Fatigue (FACT-F) scale. Effects of darbepoetin alfa on changes in hemoglobin and FACT-F scores were evaluated using LGM, controlling for age, gender, Eastern Cooperative Oncology Group performance status, health status, and total transfusions.

RESULTS

Patients receiving darbepoetin alfa had higher rates of change in hemoglobin (standardized regression coefficient [[Formula: see text]] = 0.30 to 0.53, all P < 0.05) than placebo. Patients with greater rates of change in hemoglobin reported improvements in fatigue outcomes ([Formula: see text] = 0.28 to 0.59, all P < 0.05). The total standardized effect of darbepoetin alfa on fatigue outcomes corresponded to a mean change of 0.9 to 3.5 points in FACT-F scores, with one trial demonstrating changes exceeding the minimal important difference of 3 points.

CONCLUSIONS

Darbepoetin alfa improved hemoglobin which was associated with improved fatigue across the 4 trials. Clinically, meaningful improvement in fatigue was seen in 2 trials. More complex statistical analysis models of treatment may assist in understanding the effects of erythropoiesis-stimulating agents on patient-reported outcomes.

Darbepoetin alfa for anemia in patients with low or intermediate-1 risk myelodysplastic syndromes and positive predictive factors of response

BACKGROUND

Current guidelines support the use of erythropoiesis-stimulating agents for the treatment of anemia associated with low-risk myelodysplastic syndromes (MDS).

DESIGN AND METHODS

Single-arm, open-label, multi-center, phase 2 trial that evaluated the efficacy and safety of darbepoetin alfa (DA) in patients with low or intermediate-risk MDS, hemoglobin <100 g/L, erythropoietin (EPO) levels <500 IU/L and transfusion requirements <2 units/month over the preceding 2 months. Erythroid response (major [MaR] or minor [MiR]) and fatigue (Functional Assessment of Cancer Therapy-Fatigue [FACT-F]) were evaluated at 8, 16 and 24 weeks. DA was initiated at 300 μg weekly. For patients who did not achieve MaR by 8 weeks, filgrastim 300 μg weekly was added.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01039350.

RESULTS

Forty-four patients (72.7% transfusion independent) were included. Median age was 76.0 years (range 41.3-92.4), 54.5% were male, and 90.9% presented ECOG Status (0-1). Eighteen patients received filgrastim. An erythroid response was achieved by 31 of 44 patients (70.5%) at week 8 (47.7% MaR, 22.7% MiR), 31 of 44 patients (70.5%) at week 16 (61.4% MaR, 9.1% MiR), and 32 of 44 patients (72.7%) at week 24 (61.3% MaR, 11.4% MiR). Mean (95% CI) change in FACT-F at week 24 was 3.61 (0.72 to 6.51). Baseline EPO levels <100 IU/L were a predictive factor of response. DA was well tolerated. Four mild (two iron deficiencies, flu syndrome and headache) and one fatal (thromboembolic event) adverse events were considered related to darbepoetin alfa.

CONCLUSIONS

A fixed dose of 300 μg of darbepoetin alfa weekly (with or without filgrastim) seems to be an effective and safe treatment for anemic patients with low or intermediate-risk MDS, low transfusion burden and EPO levels <500 IU/L. Results may not be extrapolable to unselected MDS patients.

Evaluation and management of fatigue in oncology: a multidimensional approach

Fatigue, one of the most common symptoms experienced by cancer patients, is multidimensional and is associated with significant impairment in functioning and overall quality of life. Although the precise pathophysiology of cancer-related fatigue (CRF) is not well understood, a number of metabolic, cytokine, neurophysiologic, and endocrine changes have been described in these patients. A better understanding of these abnormalities is likely to lead to novel therapeutic interventions. Clinically, all patients presenting with significant fatigue should be evaluated for treatable conditions that might contribute to this symptom. Exercise and treatment of anemia are the two most established interventions for CRF. Psychostimulants seem promising based on early studies. Several complementary medicine treatments that showed efficacy in preliminary studies merit further testing.

Cost-effectiveness of epoetin alfa and darbepoetin alfa in patients with chemotherapy-related anemia

Anemia frequently develops during cancer chemotherapy and contributes to a variety of adverse clinical outcomes. Correction of anemia has been shown to improve patient outcomes; however, the cost considerations of supportive-care interventions have also become increasingly important to payors. Chemotherapy-related anemia can be managed via red blood cell transfusion; however, inherent transfusion-associated risks (e.g., infectious transmission and immunosuppression) can be particularly problematic in patients with cancer. Epoetin alfa and darbepoetin alfa, alternatives to blood transfusion in patients with chemotherapy-related anemia, are both effective at improving hemoglobin levels and transfusion requirements in patients actively receiving chemotherapy. Determining the relative cost-effectiveness of these erythropoietic therapies is an active research area.

Randomized phase 2 dose-finding study of weekly administration of darbepoetin alpha in anemic patients with lung or ovarian cancer receiving multicycle platinum-containing chemotherapy

OBJECTIVE

This is the first clinical trial for Japanese to evaluate the dose-response and determine the clinically effective dose of darbepoetin alpha by weekly subcutaneously administration in anemic patients with lung cancer or ovarian cancer receiving chemotherapy.

METHODS

Eligible patients were required to have anemia (hemoglobin level of <or=11.0 g/dl). Patients were randomized in a 1:1:1 ratio to receive darbepoetin alpha (1.0, 2.25 or 4.5 microg/kg) subcutaneously once a week for up to 12 weeks. The study drug was withheld from patients who had a hemoglobin level >15.0 g/dl (for men) or 14.0 g/dl (for women), and reinstated at 50% of the previous weekly dose when the hemoglobin level decreased to <or=13.0 g/dl. Quality-of-life assessments were conducted using the Japanese version of the Functional Assessment of Cancer Therapy-anemia (FACT-an) questionnaire.

RESULTS

Hemoglobin response rate was 31.6%, 55.6% and 70.3% in 1.0, 2.25 and 4.5 microg/kg groups, respectively. The dosages of 2.25 and 4.5 microg/kg thus met the clinically effective dose criterion of at least 50% of patients achieving a hemoglobin response. The FACT-fatigue subscale had a high internal consistency with Cronbach's alpha score. Although no improvement in FACT-fatigue subscale score from baseline to the end of the treatment phase was confirmed for any dose group, there was a correlation between FACT-fatigue subscale score and hemoglobin concentration. Darbepoetin alpha appears to be well tolerated in this setting and no dose-dependent adverse events were observed.

CONCLUSIONS

Darbepoetin alpha alleviated anemia caused by platinum-based chemotherapy, and the dosage of 2.25 microg/kg was the lowest dose that met the clinically effective dose criteria when administered once weekly.

Use of latent growth curve models for assessing the effects of darbepoetin alfa on hemoglobin and fatigue

BACKGROUND

The relationship between darbepoetin alfa and fatigue in chemotherapy-induced anemia (CIA) patients is complex because of patients receiving transfusions and the mediating effect of hemoglobin. Latent growth models (LGMs) were used to examine simultaneously relationships among drug exposure, fatigue outcomes, covariates, and mediating factors.

METHODS

Data from four CIA studies (AMG 20010145: small cell lung cancer, n=547; AMG 980297: lung cancer, n=288; AMG 20000161: lymphoproliferative malignancies, n=339; AMG 20030232: non-myeloid malignancies, n=320) were analyzed separately. Patients reported fatigue using the FACT-Fatigue. The effect of darbepoetin alfa on FACT-F changes mediated through hemoglobin changes was examined with LGMs controlling for transfusions, age, sex, baseline ECOG performance status, and health status (EQ-5D VAS). Model fit was assessed using multiple indices including the comparative fit index (CFI).

RESULTS

Darbepoetin alfa increased hemoglobin levels which were associated with decreases in fatigue. Increases in hemoglobin were statistically significantly (p<0.05) related to decreases in fatigue in the studies (AMG 20030145: beta=0.28; AMG 980297: beta=0.46; AMG 20000161: beta=0.59; and AMG 20030232: beta=0.39). Darbepoetin alfa statistically significantly increased hemoglobin (AMG 20010145:beta=0.50, AMG 980297:beta=0.53, AMG 20000161:beta=0.47, and AMG 20030232:beta=0.30) while controlling for covariates. Model fit was acceptable (CFI> or =0.89) in all studies.

CONCLUSIONS

Results indicate LGMs may be a valuable statistical method for modeling complex relationships among clinical and patient reported outcomes. A statistically significant effect of darbepoetin alfa on fatigue change through hemoglobin change occurred across four studies, after modeling the effects of transfusions, age, sex, EQ-5D VAS and ECOG.

Anemia management in oncology and hematology

Anemia is frequent in cancer patients and its incidence increases with chemotherapy. The probability of requiring transfusions also increases with chemotherapy. Anemia negatively impacts survival and accentuates fatigue in cancer patients. Cancer promotes inflammatory cytokine production, which suppresses erythropoiesis and erythropoietin (EPO) production. Erythropoiesis-stimulating agents (ESAs) improve erythropoiesis and reduce transfusion needs in anemic cancer patients receiving chemotherapy. However, meta-analyses have shown an increased risk of thromboembolic (TE) events with ESA use during chemotherapy, but not increased on-study mortality or reduced overall survival. Three reasons have been proposed to explain why ESAs might have adverse effects in anemic cancer patients: tumor progression due to stimulation of tumor cell EPO receptors; increased risk of TE; and reduced survival. However, erythropoietin is not an oncogene, nor is the EPO receptor. It has also been demonstrated that erythropoietin does not stimulate tumor proliferation. Increased TE risk associated with ESAs is probably a consequence of increased blood viscosity due to excessive RBC mass elevation with concomitant plasma volume contraction, nitric oxide scavenging, and endothelial cell activation. Increased ESA dosing may also impact survival negatively because EPO contracts the plasma volume and stimulates inflammatory cytokine production independently of increasing erythropoiesis. Furthermore, transfusions themselves are associated with an increase in TE and plasma volume contraction, and these events are potentiated when ESAs are given with transfusions. An update on the management of anemia in oncology, the potential adverse events of ESAs, the benefits and risks of transfusions, and QoL are discussed in this paper.

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.

Erythropoietin or Darbepoetin for patients with cancer--meta-analysis based on individual patient data

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) reduce anemia in cancer patients and may improve quality of life, but there are concerns that ESAs might increase mortality.

OBJECTIVES

Our objectives were to examine the effect of ESAs and identify factors that modify the effects of ESAs on overall survival, progression free survival, thromboembolic and cardiovascular events as well as need for transfusions and other important safety and efficacy outcomes in cancer patients.

SEARCH STRATEGY

We searched the Cochrane Library, Medline, Embase and conference proceedings for eligible trials. Manufacturers of ESAs were contacted to identify additional trials.

SELECTION CRITERIA

We included randomized controlled trials comparing epoetin or darbepoetin plus red blood cell transfusions (as necessary) versus red blood cell transfusions (as necessary) alone, to prevent or treat anemia in adult or pediatric cancer patients with or without concurrent antineoplastic therapy.

DATA COLLECTION AND ANALYSIS

We performed a meta-analysis of randomized controlled trials comparing epoetin alpha, epoetin beta or darbepoetin alpha plus red blood cell transfusions versus transfusion alone, for prophylaxis or therapy of anemia while or after receiving anti-cancer treatment. Patient-level data were obtained and analyzed by independent statisticians at two academic departments, using fixed-effects and random-effects meta-analysis. Analyses were according to the intention-to-treat principle. Primary endpoints were on study mortality and overall survival during the longest available follow-up, regardless of anticancer treatment, and in patients receiving chemotherapy. Tests for interactions were used to identify differences in effects of ESAs on mortality across pre-specified subgroups. The present review reports only the results for the primary endpoint.

MAIN RESULTS

A total of 13933 cancer patients from 53 trials were analyzed, 1530 patients died on-study and 4993 overall. ESAs increased on study mortality (combined hazard ratio [cHR] 1.17; 95% CI 1.06-1.30) and worsened overall survival (cHR 1.06; 95% CI 1.00-1.12), with little heterogeneity between trials (I(2) 0%, p=0.87 and I(2) 7.1%, p=0.33, respectively). Thirty-eight trials enrolled 10441 patients receiving chemotherapy. The cHR for on study mortality was 1.10 (95% CI 0.98-1.24) and 1.04; 95% CI 0.97-1.11) for overall survival. There was little evidence for a difference between trials of patients receiving different cancer treatments (P for interaction=0.42).

AUTHORS' CONCLUSIONS

ESA treatment in cancer patients increased on study mortality and worsened overall survival. For patients undergoing chemotherapy the increase was less pronounced, but an adverse effect could not be excluded.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

MAIN OUTCOME MEASURES

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

RESULTS

A total of 15,007 eligible episodes of care (darbepoetin alfa, 7769 episodes [5587 patients]; epoetin alfa 7238 episodes [5157 patients]) were identified. Fewer claims were observed per episode of care for darbepoetin alfa than for epoetin alfa (mean [SD] 3.7 [4.1] vs. 5.3 [6.4]). The median time between consecutive claims was 15 days (darbepoetin alfa) and 8 days (epoetin alfa). The mean (SD) weekly doses were 105 (56) microg (darbepoetin alfa) and 34,242 (28173) U (epoetin alfa), a dose-comparison ratio of 326 : 1. Dose-comparison ratios were sensitive to assumptions about duration of clinical benefit. The mean (95% CI) weekly costs were significantly lower for darbepoetin alfa ($560 [553-567]) than for epoetin alfa ($645 [630-659], p < 0.0001) when duration of clinical benefit was considered.

CONCLUSIONS

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

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.

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

OBJECTIVE

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

METHODS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

The potency of erythropoietin-mimic antibodies correlates inversely with affinity

Preclinical animal studies have shown that Ab12.6, an agonistic human Ab targeting the erythropoietin receptor (EPOR), exhibits several potential dosing and safety features that make it an attractive clinical candidate for the treatment of anemia. Ab12.6 was derived by yeast display affinity maturation of parental Ab12, a strategy initially intended to improve off-rate and affinity for EPOR, thereby enhancing erythropoietic activity. Analysis of full-length IgGs derived from yeast clones identified sequences within Ab12 CDRH2 that independently influenced both affinity and potency. The Ab12.6 derivative displayed improved in vitro potency and in vivo efficacy, although its binding affinity to the EPOR was lower than that of the parent Ab12. Additional Ab12 derivatives also exhibited an inverse correlation between affinity and potency. These results suggest that for this class of agonistic Abs, faster off-rates may permit continuous receptor stimulation and more efficient erythropoiesis.

Blood transfusion requirements for patients with sarcomas undergoing combined radio- and chemotherapy

Patients with bony and soft tissue sarcomas may require intensive treatment with chemotherapy and radiotherapy, which often leads to a fall in haemoglobin levels, requiring blood transfusion. There may be advantages in predicting which patients will require transfusion, partly because anaemia and hypoxia may worsen the response of tumours to chemotherapy and radiotherapy. Between 1997 and 2003, a total of 26 patients who received intensive treatment with curative intent were identified. Transfusions were given to maintain the haemoglobin at 10g/dl or above during chemotherapy, and at 12 g/dl or above during radiotherapy. Eighteen (69%) required a transfusion, the majority as a result of both the chemotherapy and RT criteria. There were 78 transfusion episodes, and 181 units of blood given. In the 18 patients who required transfusion, the average number of units was 10.1, but seven patients required more blood than this. The most significant factor influencing blood transfusion was choice of intensive chemotherapy. Intensive chemotherapy and presenting Hb less than 11.6 g/dl identified 13 out of 18 patients who needed transfusion. Adding a drop in haemoglobin of greater than 1.7 g/dl after one cycle of chemotherapy identified 16 out of 18 patients who required transfusion. The seven patients who had heavy transfusion requirements were identified by age 32 or less, intensive chemotherapy and a presenting Hb of 12 g/dl or less. Erythropoietin might be a useful alternative to transfusion in selected patient groups, especially those with heavy transfusion requirements.

Darbepoetin versus epoetin alfa for the correction of anemia in cancer patients receiving radiotherapy or chemoradiotherapy treatment

INTRODUCTION

Anemia is the most frequent hematological disturbance in cancer patients, with prevalence between 30% and 90%, depending on the type of tumor, the antitumor treatment, and other factors (infection, malnutrition, bleeding, tumor infiltration of the bone marrow). A number of erythropoietic agents have shown to be effective in increasing the hemoglobin (Hb) levels, reducing the requirements for transfusion, and improving quality of life. The objective of this study is to compare darbepoetin alfa and epoetin alfa when used to correct anemia in cancer patients who are receiving radiotherapy or radiochemotherapy.

MATERIAL AND METHODS

A prospective study of 125 consecutive patients with anemia (Hb <13 g/dL in males or <12 g/dL in females) who were undergoing treatment with radiotherapy (RT) or radiochemotherapy (RCT) in our department were enrolled between March 2003 and March 2005. The treatment for the anemia was either darbepoetin alfa 150 mcg/week (62 patients, group 1) or epoetin alfa 40,000 IU/week (63 patients, group 2). Patients received iron supplements in both groups. Treatment was administered in a consecutive manner depending on tumor type. If the increase in Hb was <1 g/dL after 4 weeks of treatment, the dose was increased to 300 mcg/week in group 1 or to 60,000 IU/week in group 2. The treatment was terminated when a Hb value of ≥15 g/dL was reached during RT treatment, a Hb value of ≥14 g/dL was reached if the RT had been completed, or after 16 weeks of treatment whatever the Hb value. The mean age of patients was 63.36 ± 11.27 years, 67% were male. No significant differences were observed between the 2 groups in tumor type or stage, previous treatments, or intent to treat with RT or RCT.

RESULTS

Comparing group 1 and group 2 by intent to treat, the mean Hb at the start of treatment with the study drug was 12.1 g/dL vs 11.8 g/dL, the proportion of patients whose dose was increased was 19.7% vs 24.6%, the need for transfusion was 3.2% in each group, the duration of erythropoietic treatment was 6.5 weeks in both groups, and 2 patients in group 2 restarted treatment with epoetin alfa. The percentage of patients who responded (defined as an increase in the Hb ≥ 2 g/dL in the absence of transfusions) was of 72.6% and 66.7%, respectively. Four vascular adverse events were observed, 2 in each group. No significant differences were observed with respect to the baseline, week 4, and week 12 levels of endogenous erythropoietin, serum iron,% saturation, and ferritin. The increase in Hb 1 month after the final administration of the study drug was 2.21 g/dL in group 1 and 2.46 g/dL in group 2 (p = ns).

CONCLUSIONS

The results of our study demonstrate that both treatments are equally effective in correcting anemia in cancer patients undergoing RT or RCT.

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.

A potent erythropoietin-mimicking human antibody interacts through a novel binding site

Recombinant human erythropoietin (rHu-EPO) is used to treat anemia by activating the erythropoietin receptor (EPOR) in erythroid progenitor cells, leading to proliferation and differentiation into mature red blood cells. To allow less frequent dosing, a hyperglycosylated version of EPO has been developed with a longer half-life. In principle, an agonistic antibody targeting EPOR would offer an even longer half-life, support robust monthly dosing, and, unlike EPO products, reduce the risk of pure red cell aplasia. The efficiency of signaling and corresponding potency of previously reported antibody mimics are generally suboptimal compared with EPO and not suitable for clinical use. Here we describe a potent, fully human, agonistic antibody (ABT007) targeting EPOR that supports potent, more sustained, and less pulsatile elevation of hematocrit in a human EPOR–expressing transgenic mouse model compared with standard doses of rHu-EPO while requiring less frequent dosing. Resolution of the crystal structure of the EPOR extracellular domain (ECD) complexed to the ABT007 Fab fragment, determined at 0.32 nm, identifies a binding site that is consistent with a novel mechanism of receptor activation based on a unique antibody-imposed conformational change. These results demonstrate that a symmetric molecule can serve as a potent activator of the EPOR.

Darbepoetin Alfa Administered Every 4 Weeks for Anemia in Patients with Advanced Prostate Cancer

PURPOSE

Anemia is a common morbidity of advanced prostate cancer, and prostate cancer treatment and has been associated with a worse overall survival and reduced quality of life in patients with prostate cancer. We sought to determine if infrequent dosing of darbepoetin alfa is safe and effective in treating anemia in patients receiving systemic therapy for prostate cancer.

PATIENTS AND METHODS

Sixteen patients with histologically confirmed prostate cancer with bone metastases on androgen deprivation therapy with or without chemotherapy; and a baseline hemoglobin (Hb) < or = 12 g/dL (amended to < or = 11 g/dL) were enrolled. The primary endpoints were the proportion of patients who had a baseline Hb > or = 12.5 g/dL and the proportion whose baseline Hb increased by > or = 1 g/dL. Patients were initially treated with 300 microg of darbepoetin alfa every 4 weeks. The dose was increased to 500 microg, 800 microg, and 1000 microg at each subsequent visit if the baseline Hb was not at target and had not increased by > or = 1 g/dL during the previous 4 weeks. Treatment was planned for 6 months.

RESULTS

Treatment was well tolerated with no grade > or = 3 toxicities. Fourteen patients were assessable. The median Hb at study entry was 10.7 g/dL (range, 8.4-12). Serum Hb increased by > or = 1 g/dL in 10 patients (71%; 95% confidence interval, 42%-92%) and 7 patients (50%; 95% confidence interval, 23%-77%) reached an Hb of > or = 12.5 g/dL after treatment with doses that ranged from 300 microg to 1000 microg.

CONCLUSION

Darbepoetin alfa administration every 4 weeks is feasible and well tolerated. Target Hb increases were achieved in approximately half of the patients and required doses that ranged from 300 microg to 1000 microg.

Efficacy and Safety of Every‐2‐Week Darbepoetin Alfa in Patients with Anemia of Cancer: A Controlled, Randomized, Open‐Label Phase II Trial

This randomized, controlled trial evaluated the effect of darbepoetin alfa on hospitalization days, transfusion requirements, hemoglobin levels, and fatigue in patients with anemia of cancer (AOC). Eligible patients were anemic (hemoglobin <or=11 g/dl) due to cancer, >or=18 years old, and had not received chemotherapy or radiotherapy within 4 weeks of study screening. Patients were randomized 4:1 to receive darbepoetin alfa, 3.0 microg/kg every 2 weeks (Q2W) (n = 226), or observation only for 12 weeks (n = 59), followed by an optional 9 weeks of darbepoetin alfa, 3.0 microg/kg Q2W. Endpoints were compared between the two treatment arms at week 13. A planned interim analysis indicated that assumptions regarding hospitalization in the study design were incorrect, so the study was terminated early. Therefore, results for the primary endpoint should be interpreted cautiously. The hospitalization rate was similar (0.5 days) for both the darbepoetin alfa and observation groups (p = .73). Transfusion incidence (weeks 5-12) was significantly lower for darbepoetin alfa patients (8%) than for observation patients (22%) (p = .0092). By week 13, hemoglobin increased by 2.1 g/dl in patients receiving darbepoetin alfa, compared with 0.1 g/dl in the observation group p < .0001. Hemoglobin improvements were paralleled by an increase in Functional Assessment of Cancer Therapy-Fatigue score (mean change in score at week 13: darbepoetin alfa, 6.0; observation, 2.2; p < .05). Darbepoetin alfa Q2W can significantly improve hemoglobin levels and reduce transfusion requirements in patients with AOC, resulting in significant improvements in health-related quality of life.

A randomized, controlled trial comparing darbepoetin alfa correction/maintenance dosing with weekly dosing for treating chemotherapy-induced anemia

OBJECTIVE

To evaluate if a darbepoetin alfa correction/maintenance dosing regimen is non-inferior to a weekly regimen with respect to red blood cell transfusion requirements in patients with chemotherapy-induced anemia (CIA).

RESEARCH DESIGN AND METHODS

In this randomized, active-controlled, double-blind phase 3 trial, CIA patients were randomized 1:1 to receive darbepoetin alfa in either a correction/maintenance schedule (4.5 microg/kg weekly for 4 weeks followed by 4.5 microg/kg every 3 weeks (Q3W)) or a weekly schedule (2.25 microg/kg weekly). The primary endpoint was the transfusion incidence during weeks 1-16. Non-inferiority was to be concluded if the upper limit of the 95% confidence interval (CI) of the difference in transfusion incidence between treatment groups was below 12.5%. Hematologic responses and safety profiles were also compared.

RESULTS

Transfusion incidence (95% CI) during weeks 1-16 was 37% (32-42) and 38% (32-43) in the weekly and correction/maintenance groups, respectively. The difference (95% CI) in transfusions was 0.4% (-7.0 to 7.8), demonstrating non-inferiority between treatment groups. Similar percentages in both groups achieved and maintained hemoglobin in a target range of 11-13 g/dL and had clinically meaningful FACT-F score improvements. The median (range) time to hemoglobin response was 10 (1-17) weeks and 12 (2-17) weeks in the weekly and correction/maintenance groups, respectively. Both groups had similar safety profiles.

CONCLUSIONS

A correction/maintenance schedule with its initial two-fold higher weekly dosing and subsequent Q3W dosing yielded outcomes similar to those observed with a weekly schedule. Although correction/maintenance dosing provided no incremental clinical benefit, Q3W dosing could provide benefits of convenience and facilitate patient compliance.

Pharmacokinetic study of darbepoetin alfa: absorption, distribution, and excretion after a single intravenous and subcutaneous administration to rats

KRN321 is a hyperglycosylated analogue of recombinant human erythropoietin (rHuEPO, epoetin alfa), and its absorption, distribution, and excretion have been studied after a single intravenous and subcutaneous administration of 125I-KRN321 at a dose of 0.5 microg kg-1 to male rats. The half-lives of immunoreactive radioactivity in the terminal phase after intravenous and subcutaneous administration were 14.05 and 14.36 h, respectively, and the bioavailability rate after subcutaneous administration was 47%. The total radioactivity in tissues was lower than that in the serum in all tissues excluding the thyroid gland and skin at the injection site (subcutaneous administration). The maximum concentrations were observed in the bone marrow or skin at the injection site followed by the thyroid gland, kidneys, adrenal glands, spleen, lungs, stomach and bladder. The radioactivity found in trichloroacetic acid-precipitated fractions suggested that a high-molecular weight compound, unchanged or mixed with endogenous protein, distributed to the tissues after administration. The whole-body autoradiographic findings in both groups were in agreement with the tissue distribution mentioned above. The blood cell uptake of KRN321 was low for both groups. The excretion ratios of radioactivity into urine and faeces up to 168 h were 71.4 and 14.1% after the intravenous administration and 74.9 and 12.0% after the subcutaneous administration. There was no difference in the excretion profile of radioactivity between the two groups.

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.

Effects of Darbepoetin Alfa Administered Every Two Weeks on Hemoglobin and Quality of Life of Patients Receiving Chemotherapy

PURPOSE/OBJECTIVES

To review the effects on hemoglobin and quality of life of an every-two-week (Q2W) regimen of the erythropoietic agent darbepoetin alfa for treating patients with chemotherapy-induced anemia.

DATA SOURCES

Published articles and abstracts.

DATA SYNTHESIS

Darbepoetin alfa Q2W increases hemoglobin in patients with chemotherapy-associated anemia and is well tolerated. Increased hemoglobin is associated with improvements in fatigue and energy level. A starting dose of darbepoetin alfa 3.0 mcg/kg (approximately 200 mcg for an average 70 kg patient) Q2W produces a similar level of response to recombinant human erythropoietin.

CONCLUSIONS

Darbepoetin alfa effectively treats chemotherapy associated anemia with fewer clinic visits and fewer injections than are required with conventional erythropoietic therapy.

IMPLICATIONS FOR NURSING

The less-frequent dosing schedule of darbepoetin alfa can simplify anemia management for nurses and other clinic staff, and it offers patients greater freedom in their day-to-day activities, less dependence on caregivers, and less injection-associated discomfort.

Speed of haemoglobin response in patients with cancer: a review of the erythropoietic proteins

BACKGROUND

Patients with cancer-related anaemia generally have a poor prognosis. Evidence suggests that an effective erythropoietic protein (epoetin)-mediated haemoglobin (Hb) response provides marked improvement in quality of life (QoL). An early Hb response to erythropoietic protein therapy in these patients would appear ideal but few studies have compared the speed of response to different erythropoietic proteins, or the potential benefits associated with an early Hb response.

RESULTS AND DISCUSSION

The pharmacokinetic/pharmacodynamic profiles of commercially available erythropoietic proteins are reviewed along with available clinical data to examine Hb response and associated clinical outcomes for each of these agents. Randomised, head-to-head trials comparing epoetin alfa and darbepoetin alfa suggest that patients administered with epoetin alfa achieve a satisfactory Hb response significantly earlier than those given darbepoetin alfa, and with consistently lower monthly transfusion rates. Non-comparative studies support this, suggesting also that epoetin beta may provide a relatively faster Hb response in a greater number of patients than either epoetin alfa or darbepoetin alfa, irrespective of malignancy or chemotherapy type. Moreover, studies suggest consistently that a 'front-loading' dosing regimen with epoetin alfa does not convey improved speed of Hb response over epoetin beta administered according to current clinical practice guidelines.

CONCLUSIONS

Given the poor prognosis of anaemic patients with cancer, the use of an agent which provides clinical benefits quickly but with minimal thromboembolic risk, should be considered an essential component of anaemia management in these patients. However, more head-to-head studies are required to confirm the relative efficacy of currently available erythropoietic proteins.