A Prospective Multicenter Open-Label Study of the Effectiveness of Epoetin Beta for Patients with Low/Intermediate-1-Risk Myelodysplastic Syndrome (MDS): A Preliminary Result

Introduction : Chronic anemia impairs quality of life and adversely affects survival in patients with MDS. Recombinant erythropoietin (EPO) has been proven in maintaining hemoglobin (Hb) level and reducing red blood cell (RBC) transfusion in this group of patients. However, there were limited reports of EPO-β in MDS patients especially in Asian populations.

Method: We have conducted a phase IV, multicenter, prospective, open labelled study in patients with low/intermediate-1 risk MDS to evaluate safety and efficacy of EPO-β 30,000 or 60,000 IU/week up to 12 weeks (NCT02145026). Patients with baseline Hb < 10g/dL were eligible if they required RBC transfusion < 4 unit/ 8 weeks and serum erythropoietin < 500 mU/ml. All enrolled patients will start EPO-β 30,000 IU weekly and their erythroid response will be assessed at week 4 and every 4 weeks thereafter until the end of study. If hemoglobin level reaches ≥ 12 g/dL at any time, EPO-β should be discontinued until Hb levels are ≤ 10 g/dL. While patients with Hb level is less than 12 g/dL and increased less than 1 g/dL from baseline level, a 60,000 IU weekly of EPO-β will be administered subcutaneously until week 12. Up to the clinical cut-off date for this interim analysis, 58 patients were screened, 27 of which were eligible for safety analysis whereas 25 patients were eligible for primary efficacy analysis to evaluate response according to International Working Group (IWG 2006) response criteria in MDS.

Results: The median age of patients was 74.6 (range; 53.1-88.5), 18 (67%) were female. Three major subtypes of MDS were refractory cytopenia with multi-lineage dysplasia (RCMD, 44%), refractory cytopenia with uni-lineage dysplasia (RCUD, 32%) and refractory anemia with ring sideroblasts (RARS, 16%). Baseline Hb, hematocrit (Hct) and serum EPO were 8.1±1.3 g/dL, 25.2±3.7% and 89.5±116.6 mU/ml respectively. Twenty-five patients (92%) had serum EPO ≤ 200 mU/ml. There were 16 patients (64.0%) achieved hematologic improvement on erythroid (HI-E), while 6 patients (24.0%) achieved hematologic improvement on platelet (HI-P). Eleven patients (44.0%) (68% of responding patients) achieved Hb≥12 g/dL. Sixteen of 23 patients (69.6%) with serum EPO ≤ 200mU/ml achieved HI-E. Proportion of patients who required at least one RBC transfusion was reduced from 37% (n=10) to 11% (n=3) at the end of the study. By univariate analysis, none of baseline characteristics, including age, gender, comorbidity and MDS subtype, predicted response to EPO-β.

From 27 patients eligible for safety analysis, there were 14 adverse events (AEs) and one serious adverse event (SAE) were reported in 13 patients (48.1%). The most frequently reported AEs were increased blood pressure (28.6%; all grade1), infections (21.4%) and gastrointestinal disorders (14.3%). There was no major AEs or SAEs which considered to be related to study drug by the investigators including hypertension, pure red cell aplasia (PRCA), thromboembolism and seizure.

Conclusions

Preliminary results suggest efficacy and safety of EPO-β in the treatment of anemia in low/intermediate-1 risk MDS patients. Two-third of patients demonstrated HI-E. There were no new unknown AEs found in this study and no SAEs considered related to study drug.