A cross-sectional immunosurveillance study of anti-EPO antibody levels in CRF patients receiving epoetin alfa in 5 Ontario Renal Centers

Successful application of roxadustat in the treatment of patients with anti-erythropoietin antibody-mediated renal anaemia: a case report and literature review

Recombinant human erythropoietin (rHuEPO) has been used worldwide for treatment of renal anaemia due to its good curative effect. However, rHuEPO treatment is associated with a rare but severe complication because of the development of anti-EPO antibodies, which are difficult to treat. Currently, the main treatments for the anti-EPO antibodies include withdrawing the rHuEPO, providing blood transfusions and administrating steroid-based immunosuppressive agents. Although the above methods can alleviate anti-EPO-related anaemia, there are obvious side-effects such as decreased immunity and an increased risk of infection. Therefore, accurately identifying anti-EPO-related anaemia and effectively treating this complication is worth exploring. This current case report describes a 49-year-old female patient with chronic kidney disease that received rHuEPO subcutaneously and then developed anti-EPO antibody-mediated renal anaemia with her haemoglobin levels dropping to 37 g/l. The patient refused to be treated with steroids, so she received 120 mg roxadustat administered orally every 72 h and her Hb level increased to 110 g/l over a few months. This current case report demonstrates that roxadustat can be used to successfully treat anti-EPO antibody-mediated renal anaemia without the use of steroid-based immunosuppressants.

Evaluation of the safety and immunogenicity of subcutaneous HX575 epoetin alfa in the treatment of anemia associated with chronic kidney disease in predialysis and dialysis patients

AIM

To assess the safety and immunogenicity of subcutaneous (SC) HX575 (epoetin-α) in dialysis- and nondialysis-dependent adult patients with chronic kidney disease (CKD).

METHODS

Open-label, single-arm, multicenter study in patients (n = 416) from Germany, Italy, Poland, Romania, Russia, Turkey, and Ukraine.

RESULTS

Mean (standard deviation (SD)) age was 52.3 (15.8) years, all patients were Caucasian, and similar proportions were male/female. 250 patients (60.1%) were erythropoiesis-stimulating agent (ESA)-naïve, and 166 (39.9%) were receiving ESA maintenance therapy at study start; mean (SD) on-study treatment duration with HX575 was 43.4 (15.8) weeks and 45.3 (13.7) weeks, respectively. Binding antierythropoietin (EPO) antibodies were detected by radioimmunoprecipitation (RIP) assay in 7 patients (1.7%; incidence 0.019); 5 of these were ESA-naïve at study entry. No patient developed neutralizing antibodies as determined in a cell-based epoetin neutralizing assay. Of the 7 patients with a positive binding anti-EPO RIP assay, 4 tested negative at later time points while continuing HX575 treatment. Three patients had low titers of anti-EPO antibodies at the last study assessment. There were no clinical signs of immunogenicity or hypersensitivity.

CONCLUSIONS

SC HX575 was effective for correcting and maintaining correction of anemia, and the mean weekly dose remained stable over time.
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Biosimilar erythropoiesis-stimulating agents and the risk of developing anti-drug antibodies-a systematic review

PURPOSE

We systematically reviewed published observational studies and randomized controlled trials (RCT) reports of clinical trials on erythropoiesis-stimulating agents (ESA's). Only studies evaluating the risk of developing anti-drug antibodies (ADA) of both original and biosimilar drugs were chosen.

METHODS

Databases including PubMed, EMBASE and Cochrane Library were searched up to 17 March 2015. Two reviewers independently assessed the relevant studies for risk of bias.

RESULTS

Twenty-one publications were included. The overall prevalence of ADA in the studies was about 0.2 to 0.5 %. Most studies were not designed to monitor the development of ADA and often the study duration was too short (less than 6 months) and the patient population too small. Moreover, in many studies, the assays used only determined the presence of ADA and did not measure therapy failure due to ADA. In one RCT, as many as 13 cases (4 %) of ADA were identified.

CONCLUSION

ADA development seems to be low in short-term studies with ESA. None of the efficacy and safety issues for ESA biosimilars were judged to be adequately addressed in the evaluated literature, with respect to ADA formation, due to the study design and the assay method used.

Lack of Evidence for Molecular Mimicry in HIV-Infected Subjects

Previous studies in HIV patients have reported autoantibodies to several human proteins, including erythropoietin (EPO), interferon-α (IFN-α), interleukin-2 (IL-2), and HLA-DR, as potential mediators of anemia or immunosuppression. The etiology of these autoantibodies has been attributed to molecular mimicry between HIV epitopes and self-proteins. Here, the Luciferase Immunoprecipitation System (LIPS) was used to investigate the presence of such autoantibodies in HIV-infected adults. High levels of antibodies to HIV proteins such as capsid (p24), matrix (p17), envelope (gp41), and reverse transcriptase (RT) were detected using LIPS in both untreated and anti-retroviral-treated HIV-infected individuals but not in uninfected controls. LIPS readily detected anti-EPO autoantibodies in serum samples from subjects with presumptive pure red cell aplasia but not in any of the samples from HIV-infected or uninfected individuals. Similarly, subjects with HIV lacked autoantibodies to IFN-α, IL-2, HLA-DR and the immunoglobulin lambda light chain; all purported targets of molecular mimicry. While molecular mimicry between pathogen proteins and self-proteins is a commonly proposed mechanism for autoantibody production, the findings presented here indicate such a process is not common in HIV disease.

Prevalence of Anti-Erythropoietin Antibodies in Hemodialysis Patients without Clinical Signs of Pure Red Cell Aplasia

BACKGROUND/AIMS

The prevalence of anti-erythropoietin antibodies in renal patients without clinical evidence of pure red cell aplasia (PRCA) who respond poorly to epoetin is unknown. This study tested for anti-erythropoietin antibodies in hemodialysis patients who were either hypo- or normoresponsive to epoetin treatment.

METHODS

Epoetin hyporesponsiveness (hemoglobin < or =10.5 g/dl and epoetin > or =9,000 IU/week) and normoresponsiveness (hemoglobin >10.5 g/dl and epoetin <7,000 IU/week) were arbitrarily defined. Prevalence of anti-erythropoietin antibodies in hemodialysis patients without symptoms of PRCA was determined by screening sera of 536 patients from 35 German KfH dialysis units, using enzyme-linked immunosorbent assay (ELISA). Positive results were verified by radioimmunoprecipitation assay (RIP) and neutralizing activity was determined by bioassay.

RESULTS

Anti-erythropoietin antibodies were detected in 3 hyporesponsive and 3 normoresponsive patients using ELISA. One patient per group was verified as borderline by RIP testing; the other 4 were negative. The bioassay was negative for 1 patient; the other died unrelated to PRCA before testing. Follow-up with RIP testing after 15 months under continuous epoetin treatment was negative (4 patients, 2 deceased).

CONCLUSION

This survey did not identify anti-erythropoietin antibodies in hemodialysis patient's hyporesponsive to epoetin and does not support presumptive antibody screening as a routine work-up in these patients.

Fellow’ Forum Fellows’ Forum in Dialysis: Response to Cyclosporine A in a Patient with Pure Red Cell Aplasia Due to Antierythropoietin-α Antibodies

Reported cases of pure red cell aplasia (PRCA) from the administration of erythropoietin (EPO)-alpha molecule in the United States are rare, and the optimal treatment is still unknown. We present a patient with end-stage renal disease (ESRD) who became hyporesponsive and later unresponsive to EPO-alpha treatment a few months after initiation of hemodialysis. A comprehensive anemia examination was negative while the patient became transfusion dependent. The diagnosis of EPO-alpha-induced PRCA was confirmed by bone marrow biopsy, by undetectable serum EPO levels following the administration of a large dose of EPO-alpha, and by documenting the presence of EPO-neutralizing antibodies. Administration of cyclosporine A in addition to prednisone enabled the patient to become transfusion and EPO independent. This case further documents the possible occurrence of PRCA with EPO-alpha administration in the United States and reaffirms the potential beneficial effect of cyclosporine A.

Incidence of recombinant erythropoietin (EPO) hyporesponse, EPO-associated antibodies, and pure red cell aplasia in dialysis patients

BACKGROUND

Since 1998, an increase of anti-erythropoietin (anti-EPO) antibody-induced pure red cell aplasia (PRCA) has been reported. As data up to now consisted mostly of spontaneously reported cases the question arose about the frequency of this increase in EPO-induced PRCA. The objectives of this study were to determine the incidence and causes of recombinant EPO hyporesponse, of antibodies to EPO in patients on dialysis, and to relate the detection of anti-EPO antibodies to the presence of PRCA.

METHOD

This multicenter cohort study used existing patient data and serum samples collected at 6-month intervals from 1677 patients with incident end-stage renal disease (ESRD) participating in The Netherlands Cooperative Study on the Adequacy of Dialysis-2 (NECOSAD-2).

RESULTS

Fifty-seven patients had an inadequate EPO response, which resulted in an incidence of 16.7 per 1000 patient-years on EPO while on dialysis. All available sera specimens (N = 232) of these patients were screened for anti-EPO antibodies. The sera specimens of two of these 57 patients tested positive. Of the 57 patients with inadequate EPO response, one had clinical PRCA (incidence 0.29 per 1000 patient-years on EPO and on dialysis). Of the 1346 patients without symptoms of inadequate EPO response, one patient tested borderline positive for anti-EPO antibodies. In total, three patients developed EPO antibodies during follow-up, leading to an estimated incidence of 1.27/1000 (95% CI 0.3 to 3.7/1000) patient-years since the start of dialysis.

CONCLUSION

The incidence of inadequate EPO response in our population of dialysis patients is in concordance with tentative calculations found in the literature. Furthermore, we found the incidence of EPO-induced PRCA and EPO antibodies to be low.

Biosimilar epoetins: an analysis based on recently implemented European medicines evaluation agency guidelines on comparability of biopharmaceutical proteins

Patents of innovator biopharmaceutical products, such as epoetin, are expiring, and biosimilar versions of these products may soon enter European and American markets. Copies of these products, termed biosimilars or follow-on biologics, are not truly equivalent and cannot gain market approval through the procedure typically applied to generic drugs. We evaluated literature reports of both analytic and clinical studies conducted with biosimilar epoetin products currently marketed outside the United States and Europe in light of recently implemented European Medicines Evaluation Agency guidelines. The analytic studies reported that products differed widely in composition, did not always meet self-declared specifications, and exhibited batch-to-batch variation. Although several clinical studies demonstrated correction of anemia with biosimilar epoetins by using an open-label or placebo-controlled study design, only 4 of 22 studies were competitor controlled. Most of the studies were small (median 41 patients, range 18-1079 patients) and of short duration (median 12 wks, range 6 wks-1 yr). Clinical experience with epoetin shows that the dosage required to achieve similar hemoglobin levels varies among patients, making it impossible to demonstrate bioequivalence without a comparator. The analytic reports did not demonstrate comparability of biosimilar epoetin products with innovator epoetin alfa, and the clinical studies were not rigorous enough to show equivalent safety and efficacy of a biopharmaceutical product. The variation between products illustrates the challenge in replicating and consistently producing biopharmaceutical proteins. Immunogenic reactions with epoetin indicate that large, long-term studies are needed to adequately monitor safety.

Long-term outcome of individuals with pure red cell aplasia and antierythropoietin antibodies in patients treated with recombinant epoetin: a follow-up report from the Research on Adverse Drug Events and Reports (RADAR) Project

Since its introduction in 1988, recombinant human erythropoietin (epoetin) has been standard treatment for patients with anemia due to chronic kidney disease. From 1998 to 2004, nearly 200 epoetin-treated persons with chronic kidney disease developed antibodies to epoetin, resulting in pure red cell aplasia (PRCA). The majority of these patients received Eprex, an epoetin alfa product marketed exclusively outside the United States. Herein, we report on the long-term outcome of these individuals. For 170 chronic kidney disease patients who developed epoetin-associated PRCA and had 3 months or more follow-up information available, case reports from the Food and Drug Administration and epoetin manufacturers were reviewed for information on clinical characteristics of the patients, immunosuppressive treatments, epoetin responsiveness, and hematologic recovery. Overall, 64% of the PRCA patients received immunosuppressive therapy, including 19 who also underwent a renal transplantation. Thirty-seven percent experienced a hematologic recovery, with higher hematologic recovery rates among PRCA patients who received immunosuppressive therapy (57% vs 2%, P < .001). Among 34 patients who received epoetin after the onset of PRCA, 56% regained epoetin responsiveness. The highest rates of epoetin responsiveness were observed among persons whose antierythropoietin antibodies were undetectable when epoetin was administered (89%). Among chronic kidney disease patients with epoetin-associated PRCA, epoetin discontinuation and immunosuppressive therapy or renal transplantation is necessary for hematologic recovery. Reinitiation of epoetin therapy among individuals could be considered if antierythropoietin antibodies are undetectable.

Comparison of two recombinant erythropoietin formulations in patients with anemia due to end-stage renal disease on hemodialysis: a parallel, randomized, double blind study

Background

Recombinant human erythropoietin (EPO) is used for the treatment of last stage renal anemia. A new EPO preparation was obtained in Cuba in order to make this treatment fully nationally available. The aim of this study was to compare the pharmacokinetic, pharmacodynamic and safety properties of two recombinant EPO formulations in patients with anemia due to end-stage renal disease on hemodialysis.

Methods

A parallel, randomized, double blind study was performed. A single 100 IU/Kg EPO dose was administered subcutaneously. Heberitro (Heber Biotec, Havana, formulation A), a newly developed product and Eprex (CILAG AG, Switzerland, formulation B), as reference treatment were compared. Thirty-four patients with anemia due to end-stage renal disease on hemodialysis were included. Patients had not received EPO previously. Serum EPO level was measured by enzyme immunoassay (EIA) during 120 hours after administration. Clinical and laboratory variables were determined as pharmacodynamic and safety criteria until 216 hours.

Results

Both groups of patients were similar regarding all demographic and baseline characteristics. EPO kinetics profiles were similar for both formulations; the pharmacokinetic parameters were very close (i.e., AUC: 4667 vs. 4918 mIU.h/mL; Cmax: 119.1 vs. 119.7 mIU/mL; Tmax: 13.9 vs. 18.1 h; half-life, 20.0 vs. 22.5 h for formulations A and B, respectively). The 90% confidence intervals for the ratio between both products regarding these metrics were close to the 0.8 – 1.25 range, considered necessary for bioequivalence. Differences did not reach 20% in any case and were not determined by a formulation effect, but probably by a patients' variability effect. Concerning pharmacodynamic features, a high similitude in reticulocyte counts increments until 216 hours and the percentage decrease in serum iron until 120 hours was observed. There were no differences between formulations regarding the adverse events and their intensity. The more frequent events were pain at injection site (35.3%) and hypertension (29%). Additionally, further treatment of the patients with the study product yielded satisfactory increases in hemoglobin and hematocrit values.

Conclusion

The formulations are comparable. The newly developed product should be acceptable for long-term application.