Erythropoiesis-Stimulating Agents in the Management of Anemia in Chronic Kidney Disease or Cancer: A Historical Perspective

Comparative Safety of Long-Acting vs. Short-Acting Erythropoiesis-Stimulating Agents Among Patients Undergoing Hemodialysis

Both short-acting (epoetin alfa or beta) and long-acting (darbepoetin alfa or PEG-epoetin) erythropoiesis-stimulating agents (ESAs) are commonly prescribed for patients with kidney failure undergoing maintenance hemodialysis. We compared the risks of major adverse cardiovascular events (MACE) and of all-cause mortality associated with receipt of short- vs. long-acting ESAs. This retrospective cohort analysis included Medicare hemodialysis beneficiaries aged ≥ 18 years in the United States Renal Data System from January 2015 to December 2017. We included adults who survived > 90 days after initiating hemodialysis and received either short- or long-acting ESAs. Outcomes were MACE (first occurrence of stroke, acute myocardial infarction, or cardiovascular-related mortality) and all-cause mortality. After stabilized inverse probability of treatment weighting, Cox proportional hazards regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for each outcome. Of 68,607 patients (mean age: 65 years, 45% females), 33,658 (49%) received long-acting ESAs and 34,949 (51%) received short-acting ESAs. There was no difference in the risk of MACE associated with receipt of short- vs. long-acting ESAs (HR: 1.02 (95% CI: 0.98-1.08)). However, long-acting (vs. short-acting) ESA receipt was associated with a lower risk of all-cause mortality (HR: 0.91 (95% CI: 0.87-0.96)). Compared with short-acting ESAs, long-acting ESAs were associated with a lower risk of all-cause mortality, with no difference in the risk of MACE. Future studies with a longer follow-up are needed to confirm these findings.

Anemia diagnosis and therapy in malignant diseases: implementation of guidelines-a representative study

PURPOSE

Anemia in cancer should be diagnosed and treated according to guideline recommendations. The implementation of ESMO and German guidelines and their effect on anemia correction was analyzed.

METHODS

This retrospective epidemiological study, representative for Germany, analyzed data on anemia management of cancer patients with anemia ≥ grade 2. The Guideline Adherence Score (GLAD) for diagnosis (GLAD-D) and therapy (GLAD-T) was defined as follows: 2 points for complete, 1 point for partial, 0 point for no adherence.

RESULTS

Data were analyzed for 1046 patients. Hb levels at diagnosis of anemia were 8-10 g/dL in 899 (85.9%) patients, 7-8 g/dL in 92 (8.7%), and < 7 g/dL (5.0%) in 52. Transferrin saturation was determined in 19% of patients. Four hundred fifty-six patients received RBC (43.6%), 198 (18.9%) iron replacement, 106 (10.1%) ESA, and 60 (5.7%) vitamin B12 replacement. 60.6% of patients receiving iron replacement were treated intravenously and 39.4% were treated orally. Two hundred eighty-eight (36.6%) of 785 patients receiving transfusions had no guideline-directed indication. GLAD-D was 2 in 310 patients (29.6%), 1 in 168 (16.1%), and 0 in 568 (54.3%). GLAD-T was 2 in 270 patients (25.8%), 1 in 320 patients (30.6%), and 0 in 456 patients (43.6%). Higher GLAD-D significantly correlated with higher GLAD-T (τB = 0.176, p < 0.001). GLAD-T 2 was significantly associated with greater Hb increase than GLAD-T 0/1 (p < 0.001) at 28 days (10.2 vs. 9.7 g/dL) and at 2 months (10.4 vs. 9.9 g/dL).

CONCLUSIONS

Anemia assessment is inadequate, transfusion rates too high, and iron and ESA therapy too infrequent.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05190263, date: 2022-01-13.

Heterogeneity in leukemia cells that escape drug-induced senescence-like state

Erythropoietin (EPO) suppresses drug-induced apoptosis in EPO-receptor-positive leukemia cells and allows cells to persist after drug treatment by promoting cellular senescence. Importantly a small proportion of senescent cells can re-enter the cell cycle and resume proliferation after drug treatment, resulting in disease recurrence/persistence. Using a single-cell assay to track individual cells that exit a drug-induced senescence-like state, we show that cells exhibit asynchronous exit from a senescent-like state, and display different rates of proliferation. Escaped cells retain sensitivity to drug treatment, but display inter-clonal variability. We also find heterogeneity in gene expression with some of the escaped clones retaining senescence-associated gene expression. Senescent leukemia cells exhibit changes in gene expression that affect metabolism and senescence-associated secretory phenotype (SASP)-related genes. Herein, we generate a senescence gene signature and show that this signature is a prognostic marker of worse overall survival in AML and multiple other cancers. A portion of senescent leukemia cells depend on lysosome activity; chloroquine, an inhibitor of lysosome activity, promotes senolysis of some senescent leukemia cells. Our study indicates that the serious risks associated with the use of erythropoietin-stimulating agents (ESAs) in anemic cancer patients may be attributed to their ability to promote drug-tolerant cancer cells through the senescence program.

Recommendations From the International Consensus Conference on Anemia Management in Surgical Patients (ICCAMS)

BACKGROUND

Perioperative anemia has been associated with increased risk of red blood cell transfusion and increased morbidity and mortality after surgery. The optimal approach to the diagnosis and management of perioperative anemia is not fully established.

OBJECTIVE

To develop consensus recommendations for anemia management in surgical patients.

METHODS

An international expert panel reviewed the current evidence and developed recommendations using modified RAND Delphi methodology.

RESULTS

The panel recommends that all patients except those undergoing minor procedures be screened for anemia before surgery. Appropriate therapy for anemia should be guided by an accurate diagnosis of the etiology. The need to proceed with surgery in some patients with anemia is expected to persist. However, early identification and effective treatment of anemia has the potential to reduce the risks associated with surgery and improve clinical outcomes. As with preoperative anemia, postoperative anemia should be treated in the perioperative period.

CONCLUSIONS

Early identification and effective treatment of anemia has the potential to improve clinical outcomes in surgical patients.

The role of CD71+ erythroid cells in the regulation of the immune response

Complex regulation of the immune response is necessary to support effective defense of an organism against hostile invaders and to maintain tolerance to harmless microorganisms and autoantigens. Recent studies revealed previously unappreciated roles of CD71⁺ erythroid cells (CECs) in regulation of the immune response. CECs physiologically reside in the bone marrow where erythropoiesis takes place. Under stress conditions, CECs are enriched in some organs outside of the bone marrow as a result of extramedullary erythropoiesis. However, the role of CECs goes well beyond the production of erythrocytes. In neonates, increased numbers of CECs contribute to their vulnerability to infectious diseases. On the other side, neonatal CECs suppress activation of immune cells in response to abrupt colonization with commensal microorganisms after delivery. CECs are also enriched in the peripheral blood of pregnant women as well as in the placenta and are responsible for the regulation of feto-maternal tolerance. In patients with cancer, anemia leads to increased frequency of CECs in the peripheral blood contributing to diminished antiviral and antibacterial immunity, as well as to accelerated cancer progression. Moreover, recent studies revealed the role of CECs in HIV and SARS-CoV-2 infections. CECs use a full arsenal of mechanisms to regulate immune response. These cells suppress proinflammatory responses of myeloid cells and T-cell proliferation by the depletion of ʟ-arginine by arginase. Moreover, CECs produce reactive oxygen species to decrease T-cell proliferation. CECs also secrete cytokines, including transforming growth factor β (TGF-β), which promotes T-cell differentiation into regulatory T-cells. Here, we comprehensively describe the role of CECs in orchestrating immune response and indicate some therapeutic approaches that might be used to regulate their effector functions in the treatment of human conditions.

HIF-α Prolyl Hydroxylase Inhibitors and Their Implications for Biomedicine: A Comprehensive Review

Oxygen is essential for the maintenance of the body. Living organisms have evolved systems to secure an oxygen environment to be proper. Hypoxia-inducible factor (HIF) plays an essential role in this process; it is a transcription factor that mediates erythropoietin (EPO) induction at the transcriptional level under hypoxic environment. After successful cDNA cloning in 1995, a line of studies were conducted for elucidating the molecular mechanism of HIF activation in response to hypoxia. In 2001, cDNA cloning of dioxygenases acting on prolines and asparagine residues, which play essential roles in this process, was reported. HIF-prolyl hydroxylases (PHs) are molecules that constitute the core molecular mechanism of detecting a decrease in the partial pressure of oxygen, or hypoxia, in the cells; they can be called oxygen sensors. In this review, I discuss the process of molecular cloning of HIF and HIF-PH, which explains hypoxia-induced EPO expression; the development of HIF-PH inhibitors that artificially or exogenously activate HIF by inhibiting HIF-PH; and the significance and implications of medical intervention using HIF-PH inhibitors.

Treatment of anemia in difficult-to-manage patients with chronic kidney disease

The management of anemia of chronic kidney disease (CKD) is often challenging. In particular, for patients with underlying inflammation, comorbid type 2 diabetes or cancer, those hospitalized, and recipients of a kidney transplant, the management of anemia may be suboptimal. Responsiveness to iron and/or erythropoiesis-stimulating agents, the mainstay of current therapy, may be reduced and the risk of adverse reactions to treatment is increased in these difficult-to-manage patients with anemia of CKD. This review discusses the unique patient and disease characteristics leading to complications and suboptimal treatment response. New treatment options in clinical development, such as hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, may be particularly useful for difficult-to-treat patients. In clinical studies, HIF-PH inhibitors provided increased hemoglobin levels and improved iron utilization in anemic patients with non-dialysis-dependent and dialysis-dependent CKD, and preliminary data suggest that HIF-PH inhibitors may be equally effective in patients with or without underlying inflammation. The availability of new treatment options, including HIF-PH inhibitors, may improve treatment outcomes in difficult-to-manage patients with anemia of CKD.

Collagen Hydrolysate Corrects Anemia in Chronic Kidney Disease via Anti-Inflammatory Renoprotection and HIF-2α-Dependent Erythropoietin and Hepcidin Regulation

Anemia is a common chronic kidney disease (CKD) complication contributing to increased morbidity and mortality. Collagen-based traditional Chinese nutraceuticals have long been used in antianemic therapies. This study aims to investigate the therapeutic effectiveness of porcine collagen hydrolysate (CH) and its underlying mechanism in the treatment of renal anemia by using adenine-induced CKD mice, RAW264.7 macrophages, and HepG2 hepatoma cells, with prolyl-hydroxyproline as a reference compound for collagen-derived hydroxyproline-containing di-/tripeptides. CH was found to alleviate renal filtering dysfunction, systemic and kidney inflammation, liver hepcidin overproduction and anemia and to increase erythropoietin production and hypoxia inducible factor (HIF)-2α stability in liver and kidney in CKD mice. Prolyl-hydroxyproline exerted direct anti-inflammatory effects on lipopolysaccharide-activated macrophages and elicited stimulating and inhibiting activities on erythropoietin expression and hepcidin overproduction, respectively, in HepG2 cells by HIF-2α activation. Overall, CH was effective in correcting renal anemia via anti-inflammatory renoprotection and HIF-2α-dependent erythropoietin and hepcidin regulation.

Considerations for Use of Hematopoietic Growth Factors in Patients With Cancer Related to the COVID-19 Pandemic

Hematopoietic growth factors, including erythrocyte stimulating agents (ESAs), granulocyte colony-stimulating factors, and thrombopoietin mimetics, can mitigate anemia, neutropenia, and thrombocytopenia resulting from chemotherapy for the treatment of cancer. In the context of pandemic SARS-CoV-2 infection, patients with cancer have been identified as a group at high risk of morbidity and mortality from this infection. Our subcommittee of the NCCN Hematopoietic Growth Factors Panel convened a voluntary group to review the potential value of expanded use of such growth factors in the current high-risk environment. Although recommendations are available on the NCCN website in the COVID-19 Resources Section (https://www.nccn.org/covid-19/), these suggestions are provided without substantial context or reference. Herein we review the rationale and data underlying the suggested alterations to the use of hematopoietic growth factors for patients with cancer in the COVID-19 era.

Hypoxia-inducible factor prolyl hydroxylase inhibitors: a paradigm shift for treatment of anemia in chronic kidney disease?

INTRODUCTION

The hypoxia-inducible factor prolyl hydroxylase (HIF-PH) pathway is responsible for regulating the biosynthesis of erythropoietin (EPO) and maintaining iron homeostasis. Investigational drugs that target the HIF-PH pathway are promising alternatives for treating anemia in Chronic Kidney Disease (CKD).

AREAS COVERED

This review summarizes recent advances focused on the clinical development of HIF-PH inhibitors (HIF-PHIs) as potentially novel therapies in the treatment of anemia in CKD based on publications available on PubMed and restricted Google searches. We provide a comparison between HIF-PHIs regarding their pharmacokinetics, dosing regimens and safety concerns, structure-activity relationships, and alterations in key laboratory parameters observed in animal models and clinical trials.

EXPERT OPINION

HIF-PHIs may be advantageous in some aspects compared to the conventional erythropoiesis-stimulating agents (ESAs). While ESAs could increase the risk of cardiovascular events due to rapid rises in ESA blood levels, HIF-PHIs have been reported to maintain EPO concentrations at levels that are closer to the normal physiological ranges. Although HIF-PHIs have been demonstrated to be relatively safe and effective in clinical trials, long-term safety data are needed in order to establish whether these therapeutic agents will lead to a major paradigm change in the treatment of anemia of CKD.

Effect of fetal bovine serum on erythropoietin receptor expression and viability of breast cancer cells

Erythropoietin receptors (EPORs) are present not only in erythrocyte precursors but also in non-hematopoietic cells including cancer cells. In this study, we determined the effect of fetal bovine serum (FBS) in culture medium on the EPOR expression and viability of the estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 breast cancer cells. Using flow cytometry, we showed that the inclusion of 10% FBS in the medium increased the EPOR expressions and viabilities of MDA-MB-231 and MCF-7 cells. The MDA-MB-231 showed greater EPOR expression than MCF-7 cells, suggesting that the presence of ERs on cells is associated with poor expression of EPOR. Culture medium containing 10% FBS also caused increased number of breast cancer cells entering the synthesis phase of the cell cycle. The study also showed that rHuEPO treatment did not affect viability of breast cancer cells. In conclusion, it was shown that the inclusion of FBS in culture medium increased expression of EPOR in breast cancer cells and rHuEPO treatment had no effect on the proliferation of these cancer cells.