Evolution of Mineralocorticoid Receptor Antagonists in the Treatment of Chronic Kidney Disease Associated with Type 2 Diabetes Mellitus

Chronic kidney disease (CKD) is one of the most frequent complications associated with type 2 diabetes mellitus (T2DM) and is also an independent risk factor for cardiovascular disease. The mineralocorticoid receptor (MR) is a nuclear receptor expressed in many tissue types, including kidney and heart. Aberrant and long-term activation of MR by aldosterone in patients with T2DM triggers detrimental effects (eg, inflammation and fibrosis) in these tissues. The suppression of aldosterone at the early stage of T2DM has been a therapeutic strategy for patients with T2DM-associated CKD. Although patients have been treated with renin-angiotensin system (RAS) blockers for decades, RAS blockers alone are not sufficient to prevent CKD progression. Steroidal MR antagonists (MRAs) have been used in combination with RAS blockers; however, undesired adverse effects have restricted their usage, prompting the development of nonsteroidal MRAs with better target specificity and safety profiles. Recently conducted studies, Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease (FIDELIO-DKD) and Finerenone in Reducing Cardiovascular Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD), have reported that finerenone, a nonsteroidal MRA, improves both renal and cardiovascular outcomes compared with placebo. In this article, we review the history of MRA development and discuss the possibility of its combination with other treatment options, such as sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and potassium binders for patients with T2DM-associated CKD.

Kidney disease and congenital heart disease: Partnership for life

The literature on the relationship between kidney and cardiovascular diseases is continuously expanding. Scientists have elucidated many of the neurohormonal and hemodynamic pathways involved in cardiorenal disease. However, little is known about kidney disease in patients with congenital heart disease. Given advances in the medical and surgical care of this highly complex patient population, survival rates have dramatically improved leading to a higher percentage of adults living with congenital heart disease. Accordingly, a noticeable increase in the prevalence of kidney disease is appreciated in these patients. Some of the main risk factors for developing chronic kidney disease in the adult congenital heart disease population include chronic hypoxia, neurohormonal derangements, intraglomerular hemodynamic changes, prior cardiac surgeries from minimally invasive to open heart surgeries with ischemia, and nephrotoxins. Unfortunately, data regarding the prevalence, pathophysiology, and prognosis of chronic kidney disease in the adult congenital heart disease population remain scarce. This has led to a lack of clear recommendations for evaluating and managing kidney disease in these patients. In this review, we discuss contemporary data on kidney disease in adults with congenital heart disease in addition to some of the gaps in knowledge we face. The article highlights the delicate interaction between disease of the heart and kidneys in these patients, and offers the practitioner tools to more effectively manage this vulnerable population.

Patient and Care Partner Burden in CKD With and Without Anemia: A US-Based Survey

Rationale & Objective

Chronic kidney disease (CKD) has a far-reaching impact on both patients and care partners, which can be further compounded by frequent complications such as anemia. This study assessed the burden experienced by patients with CKD and the care partners of patients with CKD, with and without anemia.

Study Design

Online survey.

Setting & Participants

Adult patients with CKD and the care partners of adult patients with CKD living in the United States were recruited through the American Association of Kidney Patients and a third-party online panel (January 9, 2020-March 12, 2020).

Outcomes

Patient and care partner characteristics, care received or provided; health-related quality of life, and work productivity.

Analytical Approach

Descriptive statistics were reported separately based on the presence or absence of anemia.

Results

In total, 410 patients (anemia: n=190, no anemia: n=220) and 258 care partners (anemia: n=110, no anemia: n=148) completed the survey. Most patients reported receiving paid or unpaid care because of their health condition (anemia: 58.9%, no anemia: 50.9%), with an overall average of 14.2 and 11.3 h/wk among the anemia and no anemia patients, respectively. The care partners also reported providing numerous hours of care (anemia: 33.6 h/wk, no anemia: 38.0 h/wk), especially care partners living with their care recipient (anemia: 52.6 h/wk, no anemia: 42.8 h/wk). Among the patients, those with anemia reported a numerically lower average health-related quality of life (Functional Assessment of Cancer Therapy-Anemia score, anemia: 110.1; no anemia: 121.6). Most care partners reported a severe or very severe burden (Burden Scale for Family Caregivers-Short Version score≥15, anemia: 69.1%; no anemia: 58.8%). The work productivity impairment was substantial among employed patients (anemia: 44.9%, no anemia: 35.4%) and employed care partners (anemia: 47.9%, no anemia: 40.7%).

Limitations

The survey results may have been subject to selection and recall biases; moreover, the observational nature of the study does not allow for causal inferences.

Conclusions

Patients with CKD and the care partners of patients with CKD experience a considerable burden, especially when anemia is present.

Past, Present, and Future of Phosphate Management

Cardiovascular (CV) disease (CVD) accounts for >50% of deaths with known causes in patients on dialysis. Elevated serum phosphorus levels are an important nontraditional risk factor for bone mineral disease and CVD in patients with chronic kidney disease (CKD). Given that phosphorus concentrations drive other disorders associated with increased CV risk (e.g., endothelial dysfunction, vascular calcification, fibroblast growth factor-23, parathyroid hormone), phosphate is a logical target to improve CV health. Phosphate binders are the only pharmacologic treatment approved for hyperphosphatemia. Although their safety has improved since inception, the mechanism of action leads to characteristics that make ingestion difficult and unpleasant; large pill size, objectionable taste, and multiple pills required for each meal and snack make phosphate binders a burden. Side effects, especially those affecting the gastrointestinal (GI) system, are common with binders, often leading to treatment discontinuation. The presence of “hidden” phosphates in processed foods and certain medications makes phosphate management even more challenging. Owing to these significant issues, most patients on dialysis are not consistently achieving and maintaining target phosphorus concentrations of <5.5 mg/dl, let alone more normal levels of <4.5 mg/dl, indicating novel approaches to improve phosphate management and CV health are needed. Several new nonbinder therapies that target intestinal phosphate absorption pathways have been developed. These include EOS789, which acts on the transcellular pathway, and tenapanor, which targets the dominant paracellular pathway. As observational evidence has established a strong association between phosphorus concentration and clinical outcomes, such as mortality, phosphate is an important target for improving the health of patients with CKD and end-stage kidney disease (ESKD).

Recent and Emerging Therapies for Iron Deficiency in Anemia of CKD: A Review

Iron deficiency commonly contributes to the anemia affecting individuals with chronic kidney disease. Diagnostic criteria for iron deficiency in chronic kidney disease are explained. Mechanisms of functional and absolute iron deficiency and general treatment Principles as delineated in the Kidney Disease: Improving Global Outcomes guidelines are reviewed. Repletion of absolute iron deficits has progressed over time with the addition of better tolerated, more effective oral agents including ferric citrate, ferric maltol, and sucrosomial iron. Structural characteristics and trial data enabling regulatory approval of these novel oral agents are examined. Newer intravenous iron therapies including ferric carboxymaltose and ferric derisomaltose allow for fewer infusions and decreased risk of serious hypersensitivity reactions. Concerns about adverse events including cardiovascular events and infections are discussed. The potential risk of 6H syndrome due to these intravenous agents, including hypophosphatemia, osteomalacia, and pathologic fractures is emphasized. The proposed pathophysiology of 6H syndrome and hypophosphatemia is described. Ferric pyrophosphate citrate enables administration of iron for repletion through dialysate. Relative merits, costs, and risks of various iron agents such as hypersensitivity and 6H syndrome/hypophosphatemia are summarized.

Iron Deficiency in CKD Without Concomitant Anemia

The physiological role of iron extends well beyond hematopoiesis. Likewise, the pathophysiological effects of iron deficiency (ID) extend beyond anemia. Although inextricably interrelated, ID and anemia of chronic kidney disease (CKD) are distinct clinical entities. For more than 3 decades, however, nephrologists have focused primarily on the correction of anemia. The achievement of target hemoglobin (Hgb) concentrations is prioritized over repletion of iron stores, and iron status is generally a secondary consideration only assessed in those patients with anemia. Historically, the correction of ID independent of anemia has not been a primary focus in the management of CKD. In contrast, ID is a key therapeutic target in the setting of heart failure (HF) with reduced ejection fraction (HFrEF); correction of ID in this population improves functional status and quality of life and may improve cardiovascular (CV) outcomes. Given the strong interrelationships between HF and CKD, it is reasonable to consider whether iron therapy alone may benefit those with CKD and evidence of ID irrespective of Hgb concentration. In this review, we differentiate anemia from ID by considering both epidemiologic and pathophysiological perspectives and by reviewing the evidence linking correction of ID to outcomes in patients with HF and/or CKD. Furthermore, we discuss existing gaps in evidence and provide proposals for future research and practical considerations for clinicians.

Treatment of Anemia in Kidney Disease: Beyond Erythropoietin

Anemia is common in patients with chronic kidney disease. Treatment with erythropoiesis-stimulating agents has decreased transfusion rates, but has not been consistently shown to improve cardiovascular outcomes or quality of life. Moreover, treatment to hemoglobin levels normal for the general population (13-14 g/dL) has resulted in increased cardiovascular morbidity and mortality versus lower hemoglobin targets, and some patients with chronic kidney disease do not reach these lower hemoglobin targets despite escalating doses of erythropoiesis-stimulating agents. The pathophysiology of anemia in patients with chronic kidney disease has been informed by the discovery of hypoxia-inducible factor and hepcidin pathways. Recent innovations in anemia treatment leverage knowledge of these pathways to effectively raise hemoglobin levels independent of erythropoiesis-stimulating agent administration. Several agents that stabilize hypoxia-inducible factor are undergoing or have completed phase 3 clinical trials. These agents appear to have equal efficacy as erythropoiesis-stimulating agents in raising hemoglobin levels and have not been associated with major safety signals to date. Because of the potential for off-target effects from non-anemia-related gene transcription by hypoxia-inducible factor stabilization, longer-term follow-up studies and registries will be needed to ensure safety. Agents that modulate hepcidin have undergone early clinical trials with mixed results regarding safety and efficacy in increasing hemoglobin levels. Sodium-glucose cotransporter 2 inhibitors, which also decrease hepcidin levels, have been associated with increased hemoglobin levels among patients with chronic kidney disease in clinical trials exploring proteinuria and kidney disease progression.

Hypoxia-Inducible Factor Stabilization as an Emerging Therapy for CKD-Related Anemia: Report From a Scientific Workshop Sponsored by the National Kidney Foundation

The National Kidney Foundation convened an interdisciplinary international workshop in March 2019 to discuss the potential role of a new class of agents for the treatment of anemia in patients with chronic kidney disease (CKD): the hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). International experts with expertise in physiology, biochemistry, structural chemistry, translational medicine and clinical management of anemia participated. Participants reviewed the unmet needs of current anemia treatment, the biology of hypoxia-inducible factor, the pharmacology of prolyl hydroxylase inhibitors, and the results of phase 2 clinical trials of HIF-PHIs among patients with both non-dialysis dependent and dialysis-dependent CKD. The results of key phase 3 clinical trials of HIF-PHIs in the public domain as of this writing are also presented in this article although they appeared after the workshop was completed. Participants in the workshop developed a number of recommendations for further examination of HIF-PHIs which are summarized in this article and include long-term safety issues, potential benefits, and practical considerations for implementation including patient and provider education.

Strategies to Reduce Rehospitalization in Patients with CKD and Kidney Failure

Readmissions in patients with nondialysis-dependent CKD and kidney failure are common and are associated with significant morbidity, mortality, and economic consequences. In 2013, the Centers for Medicare and Medicaid Services implemented the Hospital Readmissions Reduction Program in an attempt to reduce high hospitalization-associated costs. Up to 50% of all readmissions are deemed avoidable and present an opportunity for intervention. We describe factors that are specific to the patient, the index hospitalization, and underlying conditions that help identify the "high-risk" patient. Early follow-up care, developing volume management strategies, optimizing nutrition, obtaining palliative care consultations for seriously ill patients during hospitalization and conducting goals-of-care discussions with them, instituting systematic advance care planning during outpatient visits to avoid unwanted hospitalizations and intensive treatment at the end of life, and developing protocols for patients with incident or prevalent cardiovascular conditions may help prevent avoidable readmissions in patients with kidney disease.

Iron Administration, Infection, and Anemia Management in CKD: Untangling the Effects of Intravenous Iron Therapy on Immunity and Infection Risk

Patients with chronic kidney disease (CKD) are at increased risk for infection, attributable to immune dysfunction, increased exposure to infectious agents, loss of cutaneous barriers, comorbid conditions, and treatment-related factors (eg, hemodialysis and immunosuppressant therapy). Because iron plays a vital role in pathogen reproduction and host immunity, it is biologically plausible that intravenous iron therapy and/or iron deficiency influence infection risk in CKD. Available data from preclinical experiments, observational studies, and randomized controlled trials are summarized to explore the interplay between intravenous iron and infection risk among patients with CKD, particularly those receiving maintenance hemodialysis. The current evidence base, including data from a recent randomized controlled trial, suggests that proactive judicious use of intravenous iron (in a manner that minimizes the accumulation of non-transferrin-bound iron) beneficially replaces iron stores while avoiding a clinically relevant effect on infection risk. In the absence of an urgent clinical need, intravenous iron therapy should be avoided in patients with active infection. Although serum ferritin concentration and transferrin saturation can help guide clinical decision making about intravenous iron therapy, definition of an optimal iron status and its precise determination in individual patients remain clinically challenging in CKD and warrant additional study.

The Evolution of Target Hemoglobin Levels in Anemia of Chronic Kidney Disease

Since the introduction of erythropoiesis-stimulating agents (ESAs) into clinical practice in 1989, considerable effort has been put forth toward identifying the optimal treatment strategy for managing anemia of CKD. After initial treatment of only the most severely anemic patients, therapy was subsequently expanded to include most patients on dialysis and many nondialysis CKD patients. Many nephrology societies and regulatory agencies have sought to identify the most appropriate hemoglobin levels to which ESA therapy should be targeted. As increasing evidence became available about the impacts of ESAs on varying endpoints including morbidity, mortality, and quality of life, the guidelines put forth by such agencies evolved over time. We review the literature impacting these determinations through the past 3 decades and comment on how this informs the application of this knowledge to the care of patients today.

Difficult Patient Behavior in Dialysis Facilities

Difficult behavior exhibited by dialysis patients is a spectrum that includes nonadherence, verbal or physical abuse, and threatening acts. Such behaviors may lead to harmful consequences to the patient, other patients, the facility, and staff and can culminate in involuntary discharge. It is important to recognize that these "difficult behaviors" may be due to underlying psychosocial or medical issues, which places an onus on care providers to explore further. According to the Conditions for Coverage (CfC) for dialysis facilities, it falls upon the medical director to coordinate and oversee policies for patient satisfaction, patient safety and rights, involuntary discharges, and adverse events and outcomes. Thus, medical directors are liable for their own actions, and their staff for which they have oversight, for harm or perceived harm to patients in response to difficult behaviors. Guidelines to deal with specific patient behavior scenarios have been published by the Decreasing Dialysis Patient Conflict National Task Force of the Forum of end-stage renal disease (ESRD) Networks. The common denominator for these difficult scenarios is impaired communication, and the majority of patient concerns involve issues with staff, policies, treatments, and diet. Involuntary discharge of a patient should always be viewed as a last resort, and there is a structured process described in the CfC that requires the involvement of the respective ESRD Network and the facility medical director. As physicians, we are bound by ethical and growing legal obligations to act in an appropriate, ethical, and fair manner to patients who are considered to be "difficult."

Leading the Dialysis Unit: Role of the Medical Director

The responsibilities of a dialysis unit medical director are specified in the ESRD Conditions for Coverage and encompass multiple quality, safety, and educational domains. Many of these responsibilities require leadership skills that are neither intuitive nor acquired as part of the medical director's training. An effective medical director is able to shape the culture of the dialysis facility such that patients and staff feel free to communicate their concerns regarding suboptimal processes without fear of retribution, and there is a continuous iterative process of quality improvement and safety, which values input from all stakeholders. This ultimately decreases the use of shortcuts and work-arounds that may compromise patient safety and quality because policies and procedures make it easiest to do the right thing. Fundamental to this leadership by the medical director are communications skills, staff empowerment, allocation of resources, mentoring, team building, and strategic vision. The medical director leads by example and must be present in the dialysis unit for extended periods to send a message of accessibility and commitment. Many dialysis medical directors would benefit from leadership training inside or outside their dialysis corporation.

Biosimilars-Emerging Role in Nephrology

The Food and Drug Administration (FDA) defines a "biosimilar" agent as a biologic that is highly similar to the reference or originator biologic product notwithstanding minor differences in clinically inactive components with no clinically meaningful differences in terms of the safety, purity, and potency. The advantage of biosimilars is that they are usually about 15%-30% less expensive than the reference product, which results in system-wide cost savings and increased patient access. Because biologic drugs are produced by living organisms, they are by nature heterogeneous and identical copies cannot be made, unlike generic versions of small-molecule drugs. Proposed biosimilars must undergo a rigorous evaluation process to demonstrate a high degree of structural and functional similarity with the reference biologic. Once that is confirmed, a stepwise process of comparison with the reference agent with regard to animal trials, pharmacokinetics/pharmacodynamics, immunogenicity, and human efficacy/safety is conducted. The experience with biosimilars in other highly regulated markets where patent protection for originator biologics is not as robust as in the United States has been favorable in terms of safety, efficacy, and cost savings. An FDA approval pathway was created in 2009 to expedite the approval of biosimilars; as of early 2018 nine agents had been approved through that pathway, none in nephrology. The first United States biosimilar epoetin was approved on May 15, 2018, but does not have an interchangeability designation, meaning that prescribers must specifically write for the biosimilar product for patients to receive it. Given the unfamiliarity of biosimilars within the nephrology community it is recommended that educational programs be developed to address this unmet need and for research to be conducted addressing the perceptual, clinical, and economic effect of biosimilars on our patients.

Positive Iron Balance in Chronic Kidney Disease: How Much is Too Much and How to Tell?

BACKGROUND

Regulation of body iron occurs at cellular, tissue, and systemic levels. In healthy individuals, iron absorption and losses are minimal, creating a virtually closed system. In the setting of chronic kidney disease and hemodialysis (HD), increased iron losses, reduced iron absorption, and limited iron availability lead to iron deficiency. Intravenous (IV) iron therapy is frequently prescribed to replace lost iron, but determining an individual's iron balance and stores can be challenging and imprecise, contributing to uncertainty about the long-term safety of IV iron therapy.

SUMMARY

Patients on HD receiving judicious doses of IV iron are likely to be in a state of positive iron balance, yet this does not appear to confer an overt risk for clinically relevant iron toxicity. The concomitant use of iron with erythropoiesis-stimulating agents, the use of maintenance iron dosing regimens, and the reticuloendothelial distribution of hepatic iron deposition likely minimize the potential for iron toxicity in patients on HD. Key Messages: Because no single diagnostic test can, at present, accurately assess iron status and risk for toxicity, clinicians need to take an integrative approach to avoid iron doses that impose excessive exposure while ensuring sufficient replenishment of iron stores capable of overcoming hepcidin blockade and allowing for effective erythropoiesis.

Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors: A Potential New Treatment for Anemia in Patients With CKD

Erythropoiesis-stimulating agents (ESAs) increase hemoglobin levels, reduce transfusion requirements, and have been the standard of treatment for anemia in patients with chronic kidney disease (CKD) since 1989. Many safety concerns have emerged regarding the use of ESAs, including an increased occurrence of cardiovascular events and vascular access thrombosis. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) enzyme inhibitors are a new class of agents for the treatment of anemia in CKD. These agents work by stabilizing the HIF complex and stimulating endogenous erythropoietin production even in patients with end-stage kidney disease. HIF-PH inhibitors improve iron mobilization to the bone marrow. They are administered orally, which may be a more favorable route for patients not undergoing hemodialysis. By inducing considerably lower but more consistent blood erythropoietin levels than ESAs, HIF-PH inhibitors may be associated with fewer adverse cardiovascular effects at comparable hemoglobin levels, although this has yet to be proved in long-term clinical trials. One significant concern regarding the long-term use of these agents is their possible effect on tumor growth. There are 4 such agents undergoing phase 2 and 3 clinical trials in the United States; this report provides a focused review of HIF-PH inhibitors and their potential clinical utility in the management of anemia of CKD.

Introduction of Biosimilar Therapeutics Into Nephrology Practice in the United States: Report of a Scientific Workshop Sponsored by the National Kidney Foundation

Biosimilars are biologic medicines highly similar to the reference product with no meaningful clinical differences in terms of safety, purity, and potency. All biologic medicines are produced by living cells, resulting in an inherent heterogeneity in their higher order structures and post-translational modifications. In 2010, the US Congress enacted legislation to streamline the approval process for biosimilars of products losing patent protection, with the goal of decreasing costs and improving patient access to therapeutically important but expensive biologic agents. In 2015, the US Food and Drug Administration approved the first biosimilar agent through this pathway. Approval of additional biosimilar agents in the United States, including those used by nephrologists, is anticipated. Given the relative lack of knowledge regarding biosimilars and their approval process and a lack of trust by the nephrology community regarding their safety and efficacy, the National Kidney Foundation conducted a symposium, Introduction of Biosimilar Therapeutics Into Nephrology Practice in the U.S., September 17 to 18, 2015. Issues related to manufacturing, the regulatory approval process, interchangeability, substitution/switching, nomenclature, and clinician and patient awareness and acceptance were examined. This report summarizes the main discussions at the symposium, highlights several controversies, and makes recommendations related to public policy, professional and patient education, and research needs.

Quality Measurement in Wonderland: The Curious Case of a Dialysis Readmissions Measure

The standardized readmission ratio is a new quality measure for dialysis facilities that will affect public reporting and payment beginning in 2017. Like all quality measures affecting public reporting and payment, the standardized readmission ratio was vetted by a process that included a technical expert panel convened by the US Centers for Medicare and Medicaid Services, and, then, the National Quality Forum. Unlike previous measures, standardized readmission ratio followed a tortuous path that exposed problems in the development and endorsement process. Although it is acknowledged that processes in the dialysis facility can be improved to decrease readmissions, multiple objections to the implementation of the standardized readmission ratio measure existed. This review discusses the standardized readmission ratio measure and issues related to quality metric development that are important for the nephrology community to consider.

New Options for Iron Supplementation in Maintenance Hemodialysis Patients

End-stage renal disease results in anemia caused by shortened erythrocyte survival, erythropoietin deficiency, hepcidin-mediated impairment of intestinal absorption and iron release, recurrent blood loss, and impaired responsiveness to erythropoiesis-stimulating agents (ESAs). Iron malabsorption renders oral iron products generally ineffective, and intravenous (IV) iron supplementation is required in most patients receiving maintenance hemodialysis (HD). IV iron is administered at doses far exceeding normal intestinal iron absorption. Moreover, by bypassing physiologic safeguards, indiscriminate use of IV iron overwhelms transferrin, imposing stress on the reticuloendothelial system that can have long-term adverse consequences. Unlike conventional oral iron preparations, ferric citrate has recently been shown to be effective in increasing serum ferritin, hemoglobin, and transferrin saturation values while significantly reducing IV iron and ESA requirements in patients treated with HD. Ferric pyrophosphate citrate is a novel iron salt delivered by dialysate; by directly reaching transferrin, its obviates the need for storing administered iron and increases transferrin saturation without increasing serum ferritin levels. Ferric pyrophosphate citrate trials have demonstrated effective iron delivery and stable hemoglobin levels with significant reductions in ESA and IV iron requirements. To date, the long-term safety of using these routes of iron administration in patients receiving HD has not been compared to IV iron and therefore awaits future investigations.

The approval process for biosimilar erythropoiesis-stimulating agents

A biosimilar drug or follow-on biologic drug is defined by the Public Health Service Act as a product that is "highly similar to the reference product notwithstanding minor differences in clinically active components and there are no clinically meaningful differences between the biologic product and the reference product in terms of the safety, purity and potency of the product." The advantage of biosimilar drugs is that they are significantly less expensive than the reference products, allowing for increased accessibility and cost savings. Recognizing these advantages, the US Congress passed the Biologics Price Competition and Innovation Act in 2009 as part of health care reform. The Biologics Price Competition and Innovation Act allows sponsors of biosimilar agents to seek approval by showing structural and functional similarity to the reference agent, with the extent of required clinical studies to be determined on the basis of the degree of biosimilarity with the reference product. The goal is to bring biosimilar agents to the market more efficiently while still protecting the safety of the public. The European Union has had such a process in place for a number of years. Two biosimilar epoetin agents have been approved in the European Union since 2007, and their companies are conducting trials to seek approval in the United States, because Amgen's patent protection for epoetin alfa expires in 2014. Trials completed for European Union approval of both agents showed similar efficacy and safety to the reference epoetin alfa. As with all biologics, immunogenicity concerns may persist because of the fragility of the manufacturing process and the worldwide experience with pure red cell aplasia as a result of epoetin therapy. The uptake of biosimilar epoetins after approval in the United States will depend on the balance of cost advantage against safety concerns. Competition in the marketplace will likely decrease the cost of the reference agent as well.

Systemic barriers to optimal hemodialysis access

Arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis vascular access based on their superior patency, low complication rates, improved adequacy, lower costs to the health care system, and decreased risk of patient mortality. The goals of the Fistula First Breakthrough Initiative are to achieve a prevalent AVF use rate of at least 66% nationally, to decrease central venous catheter use, and to reduce overall vascular access complication rates among patients on hemodialysis. Achieving optimal vascular access is a complex process and, unlike other dialysis outcomes, requires patient involvement as well as collaboration among nephrologists, surgeons, interventionalists, dialysis facilities, primary care physicians, and hospital systems. In 2009, the Fistula First Breakthrough Initiative assembled a team from varied backgrounds and perspectives to discover the systemic root causes as to why the AVF use rate in the United States is significantly lower than that in other industrialized countries. Ultimately, the 139 latent root causes identified by the root cause analysis team fall into the categories of patient, physician, and system. This article summarizes the current controversies in regard to improving AVF placement and reducing central venous catheter use, related to each of these three categories.