Investigating Serious Adverse Drug Reactions in Patients Receiving Erythropoiesis-Stimulating Agents: A Root Cause Analysis Using the “ANTICIPATE” Framework

BACKGROUND: Unexpected serious adverse drug reactions (sADRs) affecting patients with chronic kidney disease (CKD) who received erythropoiesis-stimulating agents were identified by study co-authors. These included pure red cell aplasia (PRCA) after administration of the Eprex formulation of epoetin or the epoetin biosimilar HX575 and fatal anaphylaxis associated with peginesatide, an erythropoietin receptor agonist. We developed and applied a structured framework to describe these sADRs, including root cause analyses and eradication efforts. METHODS: A 10-step framework termed "ANTICIPATE," focusing on signal identification, incidence, causality, and eradication guided our evaluations. RESULTS: Initial cases were identified by a hematologist (Eprex), clinical study monitors (HX575), and 4 nurses (peginesatide). The number of persons with individual ADRs was 13 PRCA cases for epoetin, 2 antibody-mediated PRCA cases for HX575, and 5 fatal anaphylaxis cases for peginesatide. Initial incidence estimates per 1000 treated persons were 0.27 for Eprex-associated PRCA, 11 for HX575-associated PRCA, and 0.38 for peginesatide fatalities. Likely causes were subcutaneous administration of epoetin formulated with polysorbate 80 (Eprex), tungsten leaching from pins included in product syringes (HX575), and inclusion of a phenol stabilizer (peginesatide). Eradication strategies included restricting Eprex administration to the intravenous route, excluding tungsten from HX575 syringes, and for peginesatide, proposed eradication was to return to single-dose vials without preservatives. CONCLUSION: Although the number of cases of each sADR was small, eradication was successful for 2 sADRs, and a proposed eradication was developed for a third sADR. The structured framework used to describe the above 3 sADRs in patients with CKD can also be used in other clinical settings.