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

Biosimilar epoetins and other "follow-on" biologics: update on the European experiences

After the patents of biopharmaceuticals have expired, based on specific regulatory approval pathways copied products ("biosimilars" or "follow-on biologics") have been launched in the EU. This article summarizes experiences with hematopoietic medicines, namely the epoetins (two biosimilars traded under five different brand names) and the filgrastims (two biosimilars, six brand names). Physicians and pharmacists should be familiar with the legal and pharmacological specialities of biosimilars: The production process can differ from that of the original, clinical indications can be extrapolated, glycoproteins contain varying isoforms, the formulation may differ from the original, and biopharmaceuticals are potentially immunogenic. Only on proof of quality, efficacy and safety, biosimilars are a viable option because of their lower costs.

Detection, evaluation, and management of iron-restricted erythropoiesis

Progress in our understanding of iron-restricted erythropoiesis has been made possible by important advances in defining the molecular mechanisms of iron homeostasis. The detection and diagnostic classification of iron-restricted erythropoiesis can be a challenging process for the clinician. Newer assays for markers of inflammation may allow more targeted management of the anemia in these conditions. The availability of new intravenous iron preparations provides new options for the treatment of iron-restricted erythropoiesis. This review summarizes recent advances regarding the detection, evaluation, and management of iron-restricted erythropoiesis.

Impact of erythropoiesis-stimulating agent prescribing at an Asian cancer center, after release of safety advisories

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) provide symptom relief and decrease blood transfusion support among patients with chemotherapy-induced anemia. However, due to increased cardiovascular events associated with off-labeled usage of ESAs, the FDA incorporated black box warnings in 2007 to include the following key points: (a) ESAs should be used only to treat anemia due to concomitant chemotherapy of a noncurative intent and (b) target hemogloblin level should not exceed 12 g/dL. Thus, this study was designed to compare the prescribing of epoetin alfa at National Cancer Centre Singapore before and after FDA black box updates. The secondary objective of this study was to evaluate the appropriateness of efficacy and toxicity monitoring of epoetin alfa.

METHODS

This was a retrospective, single-centered, drug utilization review. Patients who received at least one dose of epoetin alfa were included in this study. Utilization of epoetin alfa was segregated into two time periods: January 1, 2005 to October 15, 2007 (S1, Pre-safety advisories changes) and October 16, 2007 to December 10, 2009 (S2, Post-safety advisories changes).

RESULTS

A total of 171 patients were prescribed epoetin alfa at NCCS during the two time periods. However, only 139 patients were eligible for analysis, with 91 and 48 patients in S1 and S2 respectively. After safety advisory changes, there were more (18.2%) metastatic patients and fewer (19.1%) patients with cardiovascular co-morbidities who were prescribed epoetin alfa, the mean hemogloblin level when epoetin alfa was initiated was lowered by 0.46 g/dL, more (43%) dose adjustments were made for 'excessive' responders and more (40.7%) patients had fewer blood transfusions after epoetin alfa therapy (p < 0.05). However, blood pressure control, iron studies, and supplementation did not improve (p > 0.05).

CONCLUSION

This study suggested that oncologists have generally adopted the new ESA safety warnings and adjusted prescribing habits.

Erythropoietin: back to basics

In this issue of Blood, Sinclair and colleagues1 and Swift and colleagues2 report that the Epo receptor is barely detectable in nonhematopoietic tissues, casting doubt on the role of Epo as a pleiotropic hormone. The results not only have relevance for off-label clinical trials using recombinant human Epo for tissue-protection, but have important implications regarding Epo's alleged effects on tumor cells.

The role of erythropoietin and its receptor in growth, survival and therapeutic response of human tumor cells From clinic to bench - a critical review

Recombinant human erythropoietin (rhEPO) has been used clinically to alleviate cancer- and chemotherapy-related anemia. However, recent clinical trials have reported that rhEPO also may adversely impact disease progression and survival. The expression of functional EPO receptors (EPOR) has been demonstrated in many human cancer cells where, at least in vitro, rhEPO can stimulate cell growth and survival and may induce resistance to selected therapies. Responses to rhEPO measured by alterations in tumor cell growth or survival, activation of signaling pathways or modulation of sensitivity to anticancer agents are variable. Both methodological and inherent biological issues underlie the differential cell responses, including reported difficulties in EPOR protein detection, potential involvement of EPOR isoforms or of cytoplasmic EPOR, possible differential structure and/or binding affinities of hematopoietic versus non-hematopoietic cell EPOR, possible aberrant regulation of EPOR activity, and a functional EPO/EPOR autocrine/paracrine loop. The modulation by rhEPO of tumor cell response to anticancer agents is coincident with modulation of multiple signaling pathways, BCL-2 family proteins, caspases and NFkB. The molecular interplay of pro-survival and pro-death signals, triggered by EPO and/or by anticancer agents, is multifactorial and tightly coordinated. Expression microarray analysis may prove critical for deciphering this potentially novel network and its broad spectrum of genes and proteins.

Parenteral iron therapy in cancer-associated anemia

Anemia is common in cancer patients. Its cause is multifactorial, so a brief workup is always necessary to rule out simple, reversible causes. Anemia of chronic disease/inflammation and chemotherapy-induced anemia are the most common causes. Symptomatic or clinically severe anemia may require treatment with blood transfusion or an erythropoiesis-stimulating agent (ESA). If ESA therapy is chosen, developing evidence now suggests that, similar to chronic renal failure patients on hemodialysis, the addition of intravenous iron can improve the response to ESA because of iron-restricted erythropoiesis, even in the iron-replete patient.