Benefits of Early Hemoglobin Response to Epoetin Alfa in Elderly Patients with Chemotherapy-Related Anemia.

Abstract

Background: Previous research has shown early hemoglobin (Hb) response to epoetin alfa (EPO) therapy is associated with reduced transfusion requirements, higher Hb response rates, quality of life score improvements, and decreased EPO drug utilization. This subgroup analysis of elderly (age >/=65) patients (pts) with chemotherapy-related anemia (CRA) assesses the benefit of an early Hb response in this distinct population.Methods: Data from three large multicenter EPO clinical trials were evaluated. In EPO 1, pts received 10,000 Units TIW with potential escalation to 20,000 Units TIW. In EPO 2 and EPO 3, pts received 40,000 Units QW with escalation to 60,000 Units QW. Pts eligible for this analysis were >/=65 years of age with a non-myeloid malignancy, had a baseline Hb </=11g/dL, and received chemotherapy with or without radiotherapy (EPO 1: N=935: EPO 2: N=1,270; EPO 3: N=269). Early Hb response was defined as >/=1g/dL Hb rise following four weeks of EPO therapy, independent of transfusion in the prior 28 days. Three outcomes of pts who exhibited early Hb response were compared to those of pts who did not: proportion of pts requiring transfusion, subsequent Hb response (Hb rise >/=2 g/dL independent of transfusion), and average weekly EPO dose.Results: Early Hb response was observed in 54.1%, 47.5%, and 47.2% of pts from EPO 1, 2 and 3, respectively. In all trials, early responders had markedly lower transfusion use (EPO 1: 7.6% v 22.5%, p<.0001; EPO 2: 5.4% v 18.7%, p<.0001; EPO 3: 8.8% v 17.2%, p=.0525), higher subsequent Hb response (EPO 1: 78.7% v, 47.6%; EPO 2: 84.0% v 46.2%, EPO 3: 72.8% v. 47.8%, all studies p<.0001), and lower average weekly EPO dose (EPO 1: 30,467 vs. 40,594 Units, EPO 2: 39,286 vs. 47,310 Units; EPO 3: 38,043 v. 45,835 Units; all studies p<.0001).Conclusions: Elderly cancer pts achieving an early Hb response to EPO QW or TIW experienced greater clinical benefits (lower proportion of pts transfused, higher subsequent Hb response rates, and less EPO utilization) compared to pts who did not. These findings are consistent with analyses involving pts with younger age groups. As early Hb response is associated with clinical benefits, it should be an important goal of erythropoietic therapy for chemotherapy-induced anemia, especially in the elderly population, as demonstrated here.