#1168 Responsiveness to roxadustat in chronic kidney disease associated anemia patients by baseline hemoglobin: a secondary analysis of ROXSTAR Registry

Abstract

Abstract Background and Aims Anemia is a common complication of chronic kidney disease (CKD), and associated with increased morbidity and mortality, as well as a reduced quality of life (QoL). Various studies have shown anemia treatment in CKD patients improved the QoL. However, in ROXSTAR Registry (ChiCTR2100046322), although roxadustat corrected anemia and maintained hemoglobin (Hb) effectively, no improvement in QoL was observed. Hence, we conduct this secondary analysis of ROXSTAR to evaluate the Hb response to roxadustat treatment and the change of QoL in dialysis-dependent (DD) and non-dialysis-dependent (NDD) patients stratified by baseline Hb. Method This was a secondary analysis using existing data collected in the ROXSTAR Registry. DD & NDD Patients who received at least one dose of roxadustat and had at least one post baseline Hb were included. We described the Hb response to roxadustat in patients with lower baseline (Hb <80) g/L & higher baseline Hb (≥80 g/L). The changes from baseline to week 12 & week 24 in Quality of Life (QoL) assessed by SF-36 Vitality (V) & Physical Function (PF) subscales, and Rapid Assessment of Physical Activity (RAPA) Strength & Flexibility scores were also analyzed respectively. Results Overall, 1998 patients (1508 DD patients and 490 NDD patients) were included, there were 238 patients (131 male [55.0%]) with a mean (standard deviation [SD]) age of 49.1 (13.6) years in the lower baseline Hb group, and 1760 patients (947 male [53.8%]) with a mean age of 50.3 (13.5) in the higher baseline Hb group. The overall mean baseline Hb was 97.3 (13.9) g/L, with 71.4 (7.2) g/L and 100.8 (10.5) g/L in the two groups respectively. The median (min, max) ferritin and mean transferrin saturation were 149.6 (3.3, 2304.0) ng/mL & 22.8% (15.5) % in the lower baseline Hb group and 169.8 (3.8, 3966.0) ng/mL & 30.6% (15.7%) in the higher baseline Hb group. More patients with CRP above normal limit were in the lower baseline Hb group (30.7%) compared to patients in the other group (19.7%) (Table 1). Mean weekly roxadustat dose started at 320 mg and was maintained during the first 12 weeks (correction phase) then slightly decreased to 300 mg from week 12 until week 52 (maintenance phase) in patients with baseline Hb <80 g/L, while it was from 286 mg to 260 mg during the correction phase then decreased and maintained at around 230 mg from week 12 to week 52 in patients with baseline Hb ≥80 g/L. The mean Hb change from baseline averaged over weeks 24-36 and 36-52 was 31.9 [95% CI: 29.9, 33.9] g/L & 33.7 [95% CI: 31.8, 35.6] g/L in the lower baseline Hb group, and 11.3 [95% CI: 10.6, 12.0] g/L & 11.1 [95% CI: 10.5, 11.8] g/L in the higher baseline Hb group. The proportion (%) of patients with mean Hb ≥100 g/L averaged over the same period were 58.8% [95% CI: 51.8%, 65.7%] & 68.6% [95% CI: 61.8%, 75.3%] in the lower baseline Hb group, and 86.5% [95% CI: 84.7%, 88.3%] & 88.2% [95% CI: 86.5%, 90.0%] in the higher baseline Hb group. Patients with baseline Hb <80 g/L had numerically higher mean increases from baseline to week 12 and 24 in SF-36 V and PF sub-scores (Table 2), though no clinical meaningful change was observed in either group. Conclusion Roxadustat effectively corrected anemia in DD and NDD patients regardless of baseline Hb level. There was no clinical meaningful improvement in QoL for either group. The weekly dose of roxadustat to correct and maintain Hb was higher in patient with baseline Hb <80 g/L than in patients with baseline Hb ≥80 g/L.