Recombinant human erythropoietin in oncology: current status and further developments

Exploring the effects of post operative hyperoxic intermittent stimuli on reticulocyte levels in cancer patients: a randomized controlled study

BACKGROUND

Anemia is common among hospitalized critically ill and surgical oncological patients. The rising incidence of cancer and aggressive treatments has increased the demand for blood products, further strained by a dwindling donor pool. The normobaric oxygen paradox (NOP) has emerged as a potential avenue to increase EPO levels. While some studies support its efficacy, research remains limited in clinical settings. This study aims to assess the effectiveness of a NOP protocol in stimulating erythropoiesis, as measured by changes in reticulocyte counts, in cancer patients undergoing abdominal surgeries.

METHODS

This is a post hoc analysis of a prospective, single-center, controlled, randomized study. A total of 49 patients undergoing abdominal surgery were analyzed at the Institut Jules Bordet. Adult patients admitted to the intensive care unit (ICU) for at least 24 h were enrolled, excluding those with severe renal insufficiency or who received transfusions during the study period. Participants were randomized into two groups: a normobaric oxygen paradox (OXY) group who received 60% oxygen for 2 h on days 1, 3, and 5 post-surgery and a control (CTR) group who received standard care. Data on baseline characteristics, surgical details, and laboratory parameters were collected. Statistical analysis included descriptive statistics, chi-square tests, t-tests, Mann-Whitney tests, and linear and logistic regression.

RESULTS

The final analysis included 33 patients (median age 62 [IQR 58-66], 28 (84.8%) males, with no withdrawals or deaths during the study period. No significant differences were observed in baseline surgical characteristics or perioperative outcomes between the two groups. In the OXY group (n = 16), there was a significant rise (p = 0.0237) in the percentage of reticulocyte levels in comparison to the CTR group (n = 17), with median values of 36.1% (IQR 20.3-57.8) versus - 5.3% (IQR - 19.2-57.8), respectively. The increases in hemoglobin and hematocrit levels did not significantly differ between the groups when compared to their baselines' values.

CONCLUSIONS

This study provides preliminary evidence supporting the potential of normobaric oxygen therapy in stimulating erythropoiesis in cancer patients undergoing abdominal surgeries. While the OXY group resulted in increased reticulocyte counts, further research with larger sample sizes and multi-center trials is warranted to confirm these findings.

TRIAL REGISTRATION

The study was retrospectively registered under NCT number 06321874 on The 10th of April 2024.

Cytokinetic-driven myeloprotection after cytotoxic chemotherapy: from an old idea to a new clinical approach

Chemotherapy is the backbone of the treatment of several solid tumours and lymphomas. Myelotoxicity is often a dose-limiting toxicity and myeloprotection has always been investigated. In fact, over the years, several approaches have been studied in order to reduce the incidence of haematological toxicities and allow patients to receive effective, full-dose, chemotherapy. After the use of stimulating factors, such as granulocyte colony-stimulating factors and erythropoiesis-stimulating agents, in the very last years, a new approach has emerged. Trilaciclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor, has been studied and it has been demonstrated in several clinical trials to reduce the incidence of myelotoxicity in small-cell lung cancer patients treated with chemotherapy or chemo-immunotherapy. Its potential role has not been fully studied yet, but it represents a highly effective tool to reduce myelotoxicity, widen the applicability of full-dose chemotherapy, even in frailer patients, and finally to increase the efficacy of chemotherapy in those tumours where relative dose intensity is a standard to achieve to get the best clinical results.

Racial/ethnic and gender disparities in the use of erythropoiesis-stimulating agents and blood transfusions: cancer management under Medicare's reimbursement policy

BACKGROUND: Because of increasing safety concerns related to erythropoiesisstimulating agents (ESAs), the Centers for Medicare & Medicaid Services issued a Medicare reimbursement policy change regarding these medications in cancer patients. However, the policy established an absolute hemoglobin or hematocrit threshold to qualify for reasonable use but did not take the effect of gender and racial/ethnic differences in hemoglobin levels into consideration. OBJECTIVE: To examine disparities in the use of ESAs and blood transfusions after the Medicare policy change. METHODS: This study was an exploratory treatment effectiveness study and used the SEER-Medicare linked database. The treatment group was composed of cancer patients, whereas the control group was composed of chronic kidney disease patients. An interrupted time series design was used to examine the effect of the Medicare policy change on the use of ESAs and blood transfusions in different gender and racial/ethnic groups. RESULTS: The Medicare reimbursement policy change had an immediate effect on reducing the use of ESAs by 50% and increasing the use of blood transfusions by 10%. The immediate effect of the policy change on the monthly utilization of ESAs was 2 times greater in females (60% reduction) than males (30% reduction). Females had a 10% immediate increase in the monthly utilization of blood transfusions after the policy change. The policy change had the same immediate effect of a 50% reduction on the use of ESAs for Whites, African Americans/Blacks, and Latinos. African Americans/Blacks had a 50% immediate increase in the monthly utilization of blood transfusions after the policy change. CONCLUSIONS: Gender and racial/ethnic disparities were associated with the Medicare reimbursement policy change in the use of ESAs and blood transfusions. Thus, future policy considerations should keep biologic differences across gender and racial/ethnic groups in mind. DISCLOSURES: This study was funded by the SPARC Research Grant. The funder had no role in any part of this study. The authors have nothing to disclose.

Vaccinia virus-mediated expression of human erythropoietin in tumors enhances virotherapy and alleviates cancer-related anemia in mice

Recombinant human erythropoietin (rhEPO), a glycoprotein hormone regulating red blood cell (RBC) formation, is used for the treatment of cancer-related anemia. The effect of rhEPO on tumor growth, however, remains controversial. Here, we report the construction and characterization of the recombinant vaccinia virus (VACV) GLV-1h210, expressing hEPO. GLV-1h210 was shown to replicate in and kill A549 lung cancer cells in culture efficiently. In mice bearing A549 lung cancer xenografts, treatment with a single intravenous dose of GLV-1h210 resulted in tumor-specific production and secretion of functional hEPO, which exerted an effect on RBC progenitors and precursors in the mouse bone marrow, leading to a significant increase in the number of RBCs and in the level of hemoglobin. Furthermore, virally expressed hEPO, but not exogenously added rhEPO, enhanced virus-mediated green fluorescent protein (GFP) expression in tumors and subsequently accelerated tumor regression when compared with the treatment with the parental virus GLV-1h68 or GLV-1h209 that expressed a nonfunctional hEPO protein. Moreover, intratumorally expressed hEPO caused enlarged tumoral microvessels, likely facilitating virus spreading. Taken together, VACV-mediated intratumorally expressed hEPO not only enhanced oncolytic virotherapy but also simultaneously alleviated cancer-related anemia.

Platform for analysis of anthranilic acid N-glycan derivatives utilizing multipolarity mode LC-MS with hydrophilic interaction chromatography separation and ion trap MS/MS

BACKGROUND

The structure of glycans is complex compared with linear polymers such as proteins and nucleic acids. Structural assignment of these compounds is particularly challenging to the bioanalyst. Here we present a multipolarity mode LC-MS platform for analysis of anthranilic acid-derivatized N-glycans.

RESULTS

Multipolarity mode LC-MS analysis of N-glycan anthranilic aid (2AA) derivatives, collected under conditions that stabilize sialyloligosaccharides, provided more complete structural coverage than either mode when used alone. Structural assignment was simplified by the use of 2AA, which localizes charge to the reducing end in both modes facilitating the production of reducing end fragment dominant spectra.

CONCLUSION

Multimode analysis of high-mannose, hybrid and complex N-glycans, under conditions used in this method, is superior to either mode when used alone.

Human recombinant erythropoietin alters the flow-dependent vasodilatation of in vitro perfused rat mesenteric arteries with unbalanced endothelial endothelin-1 / nitric oxide ratio

Chronic use of human recombinant erythropoietin (r-HuEPO) is accompanied by serious vascular side effects related to the rise in blood viscosity and shear stress. We investigated the direct effects of r-HuEPO on endothelium and nitric oxide (NO)-dependent vasodilatation induced by shear stress of cannulated and pressurized rat mesenteric resistance arteries. Intravascular flow was increased in the presence or absence of the NO synthase inhibitor NG-nitro-l-arginine methyl ester (L-NAME; 10−4 mol/L). In the presence of r-HuEPO, the flow-dependent vasodilatation was attenuated, while L-NAME completely inhibited it. The association of r-HuEPO and L-NAME caused a vasoconstriction in response to the rise in intravascular flow. Bosentan (10−5 mol/L), an inhibitor of endothelin-1 (ET-1) receptors, corrected the attenuated vasodilatation observed with r-HuEPO and inhibited the vasoconstriction induced by flow in the presence of r-HuEPO and L-NAME. r-HuEPO and L-NAME exacerbated ET-1 vasoconstriction. At shear stress values of 2 and 14 dyn/cm2 (1 dyn = 10–5 N), cultured EA.hy926 endothelial cells incubated with r-HuEPO, L-NAME, or both released greater ET-1 than untreated cells. In conclusion, r-HuEPO diminishes flow-induced vasodilatation. This inhibitory effect seems to implicate ET-1 release. NO withdrawal exacerbates the vascular effects of ET-1 in the presence of r-HuEPO. These findings support the importance of a balanced endothelial ET-1:NO ratio to avoid the vasopressor effects of r-HuEPO.

American Society of Clinical Oncology/American Society of Hematology clinical practice guideline update on the use of epoetin and darbepoetin in adult patients with cancer

PURPOSE

To update American Society of Clinical Oncology/American Society of Hematology recommendations for use of erythropoiesis-stimulating agents (ESAs) in patients with cancer.

METHODS

An Update Committee reviewed data published between January 2007 and January 2010. MEDLINE and the Cochrane Library were searched.

RESULTS

The literature search yielded one new individual patient data analysis and four literature-based meta-analyses, two systematic reviews, and 13 publications reporting new results from randomized controlled trials not included in prior or new reviews.

RECOMMENDATIONS

For patients undergoing myelosuppressive chemotherapy who have a hemoglobin (Hb) level less than 10 g/dL, the Update Committee recommends that clinicians discuss potential harms (eg, thromboembolism, shorter survival) and benefits (eg, decreased transfusions) of ESAs and compare these with potential harms (eg, serious infections, immune-mediated adverse reactions) and benefits (eg, rapid Hb improvement) of RBC transfusions. Individual preferences for assumed risk should contribute to shared decisions on managing chemotherapy-induced anemia. The Committee cautions against ESA use under other circumstances. If used, ESAs should be administered at the lowest dose possible and should increase Hb to the lowest concentration possible to avoid transfusions. Available evidence does not identify Hb levels ≥ 10 g/dL either as thresholds for initiating treatment or as targets for ESA therapy. Starting doses and dose modifications after response or nonresponse should follow US Food and Drug Administration-approved labeling. ESAs should be discontinued after 6 to 8 weeks in nonresponders. ESAs should be avoided in patients with cancer not receiving concurrent chemotherapy, except for those with lower risk myelodysplastic syndromes. Caution should be exercised when using ESAs with chemotherapeutic agents in diseases associated with increased risk of thromboembolic complications. Table 1 lists detailed recommendations.

American Society of Hematology/American Society of Clinical Oncology clinical practice guideline update on the use of epoetin and darbepoetin in adult patients with cancer

PURPOSE

To update American Society of Hematology/American Society of Clinical Oncology recommendations for use of erythropoiesis-stimulating agents (ESAs) in patients with cancer.

METHODS

An Update Committee reviewed data published between January 2007 and January 2010. MEDLINE and the Cochrane Library were searched.

RESULTS

The literature search yielded one new individual patient data analysis and four literature-based meta-analyses, two systematic reviews, and 13 publications reporting new results from randomized controlled trials not included in prior or new reviews.

RECOMMENDATIONS

For patients undergoing myelosuppressive chemotherapy who have a hemoglobin (Hb) level less than 10 g/dL, the Update Committee recommends that clinicians discuss potential harms (eg, thromboembolism, shorter survival) and benefits (eg, decreased transfusions) of ESAs and compare these with potential harms (eg, serious infections, immune-mediated adverse reactions) and benefits (eg, rapid Hb improvement) of RBC transfusions. Individual preferences for assumed risk should contribute to shared decisions on managing chemotherapy-induced anemia. The Committee cautions against ESA use under other circumstances. If used, ESAs should be administered at the lowest dose possible and should increase Hb to the lowest concentration possible to avoid transfusions. Available evidence does not identify Hb levels ≥ 10 g/dL either as thresholds for initiating treatment or as targets for ESA therapy. Starting doses and dose modifications after response or nonresponse should follow US Food and Drug Administration-approved labeling. ESAs should be discontinued after 6 to 8 weeks in nonresponders. ESAs should be avoided in patients with cancer not receiving concurrent chemotherapy, except for those with lower risk myelodysplastic syndromes. Caution should be exercised when using ESAs with chemotherapeutic agents in diseases associated with increased risk of thromboembolic complications. Table 1 lists detailed recommendations.

Hypoxia, inflammation, and the tumor microenvironment in metastatic disease

Metastasis, the leading cause of cancer deaths, is an intricate process involving many important tumor and stromal proteins that have yet to be fully defined. This review discusses critical components necessary for the metastatic cascade, including hypoxia, inflammation, and the tumor microenvironment. More specifically, this review focuses on tumor cell and stroma interactions, which allow cell detachment from a primary tumor, intravasation to the blood stream, and extravasation at a distant site where cells can seed and tumor metastases can form. Central players involved in this process and discussed in this review include integrins, matrix metalloproteinases, and soluble growth factors/matrix proteins, including the connective tissue growth factor and lysyl oxidase.

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.

Outcomes and predicting response in anaemic chemotherapy patients treated with epoetin alfa. A multicentre, 4-month, open-label study in Australia and New Zealand

BACKGROUND

The aim of the study was to evaluate the effectiveness, safety, and clinical outcomes of erythropoietin therapy in the treatment of anaemic cancer subjects receiving chemotherapy and to examine hypochromic red blood cell measurement as an indicator of functional iron sufficiency and as a predictor of responsiveness or non-responsiveness to erythropoietin therapy.

METHODS

Patients who had a non-myeloid malignancy, had Hb < or = 11.0 g/dL, had a life expectancy of more than 6 months, were 18 years or older, were receiving chemotherapy and would continue to be treated for at least 2 months were given s.c. epoetin alfa three times a week.

RESULTS

Haemoglobin levels increased significantly at all time periods compared with baseline and the number of transfusions received decreased significantly at all time periods compared with baseline. Quality of life as measured by Functional Assessment of Cancer Therapy-Anaemia showed significant increases at months 2 and 4 and there were significant improvements in the fatigue subscale at both time points (P < 0.05). Significant improvements at end-point were observed for the physical, emotional and functional well-being, and additional concern subscales (all P < 0.05). Haematocrit and reticulocytes increased significantly at end-point compared with at baseline (haematocrit 33.4 vs 28.3%, P < 0.001; reticulocytes 105.8 vs 78.6 x 10(9)/dL, P = 0.005). The percentage of hypochromic red blood cells did not show predictive value for response to treatment status.

CONCLUSION

Epoetin alfa improved haemoglobin levels and quality of life in anaemic cancer patients receiving chemotherapy.

Prevention of hypoxia by myoglobin expression in human tumor cells promotes differentiation and inhibits metastasis

As a tumor grows, it requires increased amounts of oxygen. However, the tumor blood vessels that form to meet this demand are functionally impaired, leading to regions of hypoxia within the tumor. Such hypoxia is one of the hallmarks of malignancy and is thought to promote a number of tumorigenic properties. Here, we sought to determine how tumors without hypoxia would progress by engineering A549 human lung carcinoma cells to ectopically express myoglobin (Mb), a multifunctional heme protein that specializes in oxygen transport, storage, and buffering. Mb expression prevented the hypoxic response in vitro and delayed tumor engraftment and reduced tumor growth following xenotransplantation into mice. Experimental tumors expressing Mb displayed reduced or no hypoxia, minimal HIF-1alpha levels, and a homogeneously low vessel density. Mb-mediated tumor oxygenation promoted differentiation of cancer cells and suppressed both local and distal metastatic spreading. These effects were primarily due to reduced tumor hypoxia, because they were not observed using point-mutated forms of myoglobin unable to bind oxygen and they were abrogated by expression of a constitutively active form of HIF-1alpha. Although limited to xenograft models, these data provide experimental proof of the concept that hypoxia is not just a side effect of deregulated growth but a key factor on which the tumor relies in order to promote its own expansion.

Linking anemia to inflammation and cancer: the crucial role of TNFalpha

Erythropoiesis is considered as a multistep and tightly regulated process under the control of a series of cytokines including erythropoietin (Epo). Epo activates specific signaling pathways and leads to activation of key transcription factors such as GATA-1, in order to ensure erythroid differentiation. Deregulation leads to a decreased number of red blood cells, a hemoglobin deficiency, thus a limited oxygen-carrying capacity in the blood. Anemia represents a frequent complication in various diseases such as cancer or inflammatory diseases. It reduces both quality of life and prognosis in patients. Tumor necrosis factor alpha (TNFalpha) was described to be involved in the pathogenesis of inflammation and cancer related anemia. Blood transfusions and erythroid stimulating agents (ESAs) including human recombinant Epo (rhuEpo) are currently used as efficient treatments. Moreover, the recently described conflicting effects of ESAs in distinct studies require further investigations on the molecular mechanisms involved in TNFalpha-caused anemia. The present study aims to evaluate the current knowledge and the importance of the effect of the proinflammatory cytokine TNFalpha on erythropoiesis in inflammatory and malignant conditions.

Effects of exercise in combination with epoetin alfa during high-dose chemotherapy and autologous peripheral blood stem cell transplantation for multiple myeloma

PURPOSE/OBJECTIVES

To determine the effect of aerobic and strength resistance training and epoetin alfa (EPO) therapy on transfusions, stem cell collections, transplantation recovery, and multiple myeloma treatment response.

DESIGN

Randomized clinical trial.

SETTING

A myeloma research and therapy center in the south central United States.

SAMPLE

135 patients with multiple myeloma, 120 evaluable.

METHODS

Random assignment to exercise or usual care groups. All patients received EPO based on an algorithm. Aerobic capacity, using the six-minute walk test, was assessed prior to induction chemotherapy, prior to stem cell mobilization, and following stem cell collection for all patients and before and after transplantation for patients continuing in the study. Data analysis included analysis of variance to compare other outcome variables by groups.

MAIN RESEARCH VARIABLES

Number of red blood cell and platelet transfusions during transplantation, number of attempts at and total number of days of stem cell collection, time to recovery after transplantation, and response to intensive therapy for multiple myeloma.

FINDINGS

Recovery and treatment response were not significantly different between groups after transplantation. The exercise group had significantly fewer red blood cell transfusions and fewer attempts at stem cell collection. Serious adverse events were similar in each group.

CONCLUSIONS

Exercise with prophylactic EPO therapy reduces the number of RBC transfusions and attempts at stem cell collection for patients receiving intensive treatment for multiple myeloma.

IMPLICATIONS FOR NURSING

Exercise is safe and has many physiologic benefits for patients receiving multiple myeloma treatment.

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.

Pharmacokinetics and Pharmacodynamics of epoetin delta in two studies in healthy volunteers and two studies in patients with chronic kidney disease

BACKGROUND

Epoetin delta, unlike recombinant erythropoietins, is produced in a human cell line and therefore has a human-type glycosylation profile.

OBJECTIVES

The pharmacokinetics of epoetin delta were examined in 2 studies in healthy volunteers and 2 studies in patients with chronic kidney disease.

METHODS

In study 1, 21 healthy men were randomized to receive epoetin delta 15, 40, or 100 IU/kg IV tiw or placebo for 4 weeks. In study 2, an open-label, cross-over study, 32 healthy volunteers were randomized to receive single doses of epoetin delta 75 IU/kg IV or SC. In study 3, 40 patients receiving hemodialysis were withdrawn from epoetin alfa and randomized to receive epoetin delta or epoetin alfa 50 or 100 IU/kg tiw for 4 weeks. Study 4 was a single-dose study comparing epoetin delta 150 and 300 IU/kg IV or SC in 28 hemodialysis patients.

RESULTS

In study 1, after repeated dosing (day 24) in healthy men, mean C(max) values ranged from 219.9 to 1793.0 enzyme-linked immunosorbent assay units (EU)/L; AUC from 827 to 9318 h x EU/L; C1 from 0.014 to 0.024 L/h per kg; Vd from 0.067 to 0.076 L/kg; and t(1/2) from 2.23 to 3.35 hours. There was evidence of a dose-dependent effect of epoetin delta on hemoglobin levels and hematocrit, with doses of 40 and 100 IU/kg associated with significant increases compared with 15 IU/kg (P < 0.001 for dose trend). The only adverse event occurring in > or = 10% of healthy individuals in study 1 was headache (1 [20.0%] in the epoetin delta 15 IU-kg group, 3 [60.0%] in the epoetin delta 100-IU/kg group, 2 [33.3%] in the placebo group). In study 2 in healthy volunteers, mean values for epoetin delta 75 IU/kg IV were 1771 EU/L for C(max), 10,632 h x EU/L for AUC, 0.010 L/h per kg for Cl, 0.074 L/kg for Vd, and 5.12 hours for t(1/2); the corresponding values for epoetin delta 75 IU/kg SC were 113 EU/L, 3231 h x EU/L, 0.035 L/h per kg, 0.760 L/kg, and 14.90 hours. The serum epoetin delta concentration peaked after 10.9 hours with subcutaneous administration. The most common adverse event in study 2 was back pain (10 [31.3%] individuals). In study 3 in patients receiving hemodialysis, mean values for C(max) and AUC with a single dose of epoetin delta 50 IU/kg were 1103 EU/L and 10,896 h x EU/L, respectively, and with the corresponding dose of epoetin alfa were 1354 EU/L and 9957 h x EU/L. Values for the 100-IU/kg doses were approximately double those for the 50-IU/kg doses. Values for Cl, Vd, and t(1/2) were numerically similar for epoetin delta and epoietin alfa across doses. Epoetin delta 100 IU/kg was associated with a numerically greater rate of increase in hemoglobin compared with the 50-IU/kg dose (mean, 0.025 vs -0.004, respectively); the results were similar for epoetin alfa (0.029 vs -0.001). The difference between epoetin alfa and epoetin delta was not statistically significant. The most common adverse events were related to edema (peripheral edema: 60%/50% for epoetin delta 50/100 IU/kg and 60%/60% for epoetin alfa 50/100 IU/kg; facial edema: 30%/30% and 50%/70%, respectively; generalized edema: 50%/30% and 40%/40%). In study 4 in patients receiving hemodialysis, mean C(max) values with epoetin delta 150 and 300 IU/kg IV were 3257 and 4770 EU/L, respectively; the corresponding mean values were 36,208 and 77,736 h x EU/L for AUC, 0.007 and 0.005 L/h per kg for Cl; 0.097 L/kg for Vd in both groups; and 9.9 and 13.2 hours for t(1/2). With epoetin delta 150 and 300 IU/kg SC, the respective values were 162.2 and 467.7 EU/L, 9547 and 27,888 h x EU/L, 0.026 and 0.020 L/h per kg, 1.28 and 0.78 L/kg, and 33.1 and 27.8 hours. The only adverse event occurring in > or = 10% of subjects was headache (2 [40.0%] in the epoetin delta 150-IU/kg IV group, 3 [50.0%] in the epoetin delta 300-IU/kg SC group). No neutralizing anti-erythropoietin antibodies were detected in any individual. The bioavailability of subcutaneous epoetin delta is approximately 30%, and concentrations peak later and decline more slowly than with intravenous injection. Pharmacokinetic parameters in hemodialysis patients were similar to those in healthy individuals, although AUC and t(1/2) were numerically higher (by 49% and 34%, respectively).

CONCLUSIONS

These studies in healthy volunteers and patients with chronic kidney disease indicate that the pharmacokinetics of epoetin delta are dose dependent but nonlinear, leading to dose-dependent increases in hemoglobin levels. The pharmacodynamic response to epoetin delta appeared to be as expected for an epoetin.

Safety considerations for erythropoietin treatment in patients with cancer

Cancer-related anaemia, which affects many patients with cancer, can effectively be treated by erythropoietic proteins. Erythropoietic proteins increase haemoglobin levels, reduce the risk for transfusions and also improve the quality of life of patients. When used according to published practice guidelines, these proteins benefit many patients and are generally well tolerated. Important side effects are hypertension and thromboembolic events, either of which occurs in < 10% of the patients. Administration only in anaemic patients, avoidance of target haemoglobin levels > 130 g/l, proper dose adjustments and close monitoring during treatment will ensure the clinical safety of these proteins. However, the association between erythropoietic proteins and outcome of anticancer therapy, including survival, requires further study.