An open-label, multiple dose, multicenter, dose-finding study (NCT00717366) was conducted to determine the dose of intravenous Mircera when converting from treatment with another ESA (epoetin alfa/beta or darbepoetin alfa). The study was conducted in 64 pediatric patients with CKD who were on hemodialysis and who had stable hemoglobin (Hb) levels while previously receiving another ESA. The mean age of the patients was 13 years (age range: 5 to 17 years); 39% were 5 to 11 years of age, and 61% were 12 to 17 years of age. The patient population was 53% male, 72% White, 3% Black, 11% Asian and 14% Other. Eligible patients were administered Mircera intravenously once every 4 weeks for 20 weeks. After the first administration of Mircera, dosage adjustments were permitted to maintain target Hb levels.

Efficacy was established based on the change in Hb concentration (g/dL) between the baseline and evaluation periods. Of the two conversion factors studied, the recommended conversion factor for Mircera [see Dosage and Administration (2.2)] was confirmed based on patients maintaining Hb within target levels. Among the 48 patients who received Mircera dosed using the recommended conversion factor, 9 patients withdrew due to renal transplant, 2 patients withdrew due to administrative reasons, 1 died, and 1 patient refused treatment. One of the 13 patients who withdrew from the study entered the evaluation period (weeks 17 to 21). For the 36 patients who entered the evaluation period and received the dose of Mircera calculated using the recommended conversion factor, the mean change in Hb concentration from baseline between the baseline and the evaluation period was -0.15 g/dL with 95% CI (-0.49, 0.2).

Supportive efficacy results in the group treated with Mircera using the recommended conversion factor demonstrated that 75% of patients maintained Hb values within ± 1 g/dL of baseline and 81% maintained Hb values within 10 to 12 g/dL during the evaluation period. Seventy-seven percent (77%) of patients had a dose adjustment (either a dose decrease, increase or both). 

A second open-label, single-arm, multicenter study (NCT03552393) was performed to ascertain the optimal starting dose of Mircera administered subcutaneously for the maintenance treatment of anemia in 40 pediatric patients with CKD on dialysis, or not on dialysis when switching from stable subcutaneous (SC) treatment with epoetin alfa, epoetin beta or darbepoetin alfa. The mean age of patients was 10 years (age range: 4.8months to 17 years); 30 % were less than 5 years of age, 27.5% were 5 to 11 years of age, and 42.5% were 12 years of age or older. The patient population was 58% male, 75% White, 8% Black, and 10% Hispanic or Latino. The starting dose was based on the conversion factors obtained from the intravenous dose-finding study. Mircera was administered SC once every 4 weeks for 20 weeks. Similarly, in this study, efficacy was established based on the change in Hb concentration (g/dL) between the baseline and evaluation periods. The study confirmed that the conversion factors are appropriate. Among the 40 patients who received Mircera, 2 patients (5%) discontinued during the evaluation period. The reasons for discontinuation from the evaluation period were kidney transplant and use of prohibited medication. An additional 4 patients discontinued from the extension period due to kidney transplant. For the 38 patients who had Hb concentration data available during the evaluation period (Weeks 17-21), the mean change in Hb concentration between the baseline and the evaluation period was 0.48 g/dL with 95% CI (0.15, 0.82).

Supportive efficacy results demonstrated that 50% of patients maintained Hb values within ± 1 g/dL of baseline and 63% maintained Hb values within 10 to 12 g/dL during the evaluation period. Dose adjustments (either a dose decrease, increase or both) were reported in 85% of patients.