[Opatija study: observation of hemodialysis patients and titration of CERA dose just switched from another erythropoiesis stimulating agent].

INTRODUCTION: Anemia is a well-documented consequence of chronic kidney disease, its frequency increases with the progression of renal failure and occurs in up to 95% of patients with end stage renal disease (ESRD). Erythropoietin stimulating agents (ESAs) have become the standard of care in the treatment of renal anemia. The use of methoxy polyethylene glycol-epoetin beta, continuous erythropoietin receptor activator, represents an important benefit in clinical practice.

AIM: The aim of the OPATIJA study was to compare the efficacy and safety of maintaining hemoglobin levels in dialysis patients and to assess its variability in a parallel-group design. Patients were randomly assigned to receive methoxy polyethylene glycolepoetin beta once monthly in "normal" dose conversion according to the label of record or "low" or "alternative" dose conversion widely spread according to previous ESA doses.

SUBJECTS AND METHODS: A total of 79 patients were included in the study. The patients who had undergone continuous maintenance intravenous ESA therapy were divided into two parallel groups: group 1 including 36 patients directly switched to CERA according to the manufacturer recommended dosage; and group 2 including 43 patients that were switched by using "low" or "alternative" dose conversion widely spread according to previous ESA doses. During the 18-month period, each patient's anemia parameters, i.e. hemoglobin level, serum iron concentration, TSAT and ferritin, were monitored at intervals not longer than two months. According to hemoglobin levels, the dosage of CERA was adjusted if needed along with iron supplementation.

RESULTS: At the end of the study, the two groups consisted of 51 patients: 26 of those treated with the recommended dose of CERA and 25 treated with the alternative dose. In the normal conversion group, the mean hemoglobin level during the course of the study was 104.41 g/L with the mean monthly dose of 104.33 mcg CERA. In the alternative conversion group, the mean hemoglobin level during the course of the study was 105.33 g/L with the mean monthly dose'of 113.08 mcg CERA. In the alternative conversion group, 33% of patients had Hb levels in the tight recommended range of 110-120 g/L. In 30% of patients, Hb levels were 100-110 g/L, in 29% less than 100 g/L, and in 8% more than 120 g/L. The mean Hb levels at the beginning and the end of the study did not differ significantly, except for the patient group with Hb levels >120 g/L, where 7% of patients with recommended dosing and none of the patients from the alternative dosing group had such levels (P=0.017). Hemoglobin variability higher than 10 and 20 g/L was recorded in both groups, but less frequently in the alternative CERA dosing group.

CONCLUSION: Both treatments with the recommended and alternative conversion dosing achieved and maintained target hemoglobin level. Study results confirmed the need of individualized approach in the treatment of anemia in ESRD patients receiving hemodialysis, resulting in less potentially harmful hemoglobin variability.