Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of Mircera cannot be directly compared to rates in the clinical trials of other drugs and may not reflect the rates observed in practice.

The data described below reflect exposure to Mircera in 2737 patients, including 1451 exposed for 6 months and 1144 exposed for greater than one year. Mircera was studied primarily in active-controlled studies (n=1789 received Mircera, and n=948 received another ESA) and in long-term follow up studies. The population was 18 to 92 years of age, 58% male, and the percentage of Caucasian, Black (including African Americans), Asian and Hispanic patients were 73%, 20%, 5%, and 9%, respectively. Approximately 85% of the patients were receiving dialysis. Most patients received Mircera using dosing regimens of once every two or four weeks, administered subcutaneously or intravenously.

The most commonly reported adverse reactions in ≥10% of patients were hypertension

In the controlled trials, the rates of serious adverse reactions did not importantly differ between patients receiving Mircera and another ESA (38% vs. 42%) except for the occurrence of serious gastrointestinal hemorrhage (1.2% vs. 0.2%). Serious hemorrhagic adverse reactions of all types occurred among 5% and 4% of patients receiving Mircera or another ESA, respectively.

In an open-label, multiple dose study, 64 pediatric patients (ages 5 to 17 years) with CKD who were on hemodialysis and who had stable hemoglobin levels while previously receiving another ESA (epoetin alfa/beta or darbepoetin alfa) were then converted to Mircera administered intravenously once every 4 weeks for 20 weeks (core study period). Patients who completed the core study period with hemoglobin within ± 1 g/dL of their baseline hemoglobin and within the target range of 10 to 12 g/dL were eligible to enter an optional 52-week safety extension period (total duration of treatment, up to 73 weeks). In the extension period, 25 (out of 37) patients were treated for at least an additional 5 months. During the whole study (core study and safety extension), 33 patients were exposed to Mircera for at least 6 months and 19 were exposed for greater than 15 months.

All reported adverse reactions regardless of causality (more than 5% incidence) in the pediatric population included headache (22%), nasopharyngitis (22%), hypertension (19%), vomiting (11%), bronchitis (9%), abdominal pain (8%), arteriovenous fistula thrombosis (6%), cough (6%), device related infection (6%), hyperkalemia (6%), pharyngitis (6%), pyrexia (6%), thrombocytopenia (6%), and thrombosis in device (6%).

A second open-label, single-arm, multicenter study was conducted to ascertain the optimal starting dose of Mircera given subcutaneously for the maintenance treatment of anemia in 40 pediatric patients (ages 3 months to 17 years) with CKD on dialysis or not on dialysis. Patients completing the 20 weeks of treatment (core period) with Hb within ±1 g/dL of their baseline Hb and within the target range of 10 to 12 g/dL, were eligible to enter an optional 24-week safety extension period. Mircera was administered subcutaneously once every 4 weeks for the duration of the study. Thirty-eight (38) patients were exposed to Mircera for 20 weeks, and 21 patients were exposed to Mircera for 44 weeks. Overall, the pattern of adverse events reported was similar to the established safety profile of Mircera in adult patients and the patients aged 5 to 17 years in the previous intravenous study.

The following adverse reactions have been identified during post-approval use of Mircera. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Stevens-Johnson syndrome/toxic epidermal necrolysis has been reported

Cases of PRCA and of severe anemia, with or without other cytopenias that arise following the development of neutralizing antibodies to erythropoietin have been reported in patients treated with Mircera