Darbepoetin alfa for treating chemotherapy-induced anemia in patients with a baseline hemoglobin level < 10 g/dL versus > or = 10 g/dL: an exploratory analysis from a randomized, double-blind, active-controlled trial.

BACKGROUND: Several studies have shown that darbepoetin alfa, an erythropoiesis-stimulating agent (ESA), can reduce transfusions and increase hemoglobin (Hb) levels in patients with chemotherapy-induced anemia (CIA). Recent safety concerns, however, have prompted changes to ESA product information. In the European Union and United States, ESA therapy initiation for CIA is now recommended at a Hb level < or = 10 g/dL. The present exploratory analysis examined how ESA initiation at this Hb level may impact patient care. METHODS: Data from a phase 3 randomized trial were retrospectively reanalyzed. CIA patients with nonmyeloid malignancies were randomized 1:1 to 500 mcg darbepoetin alfa every three weeks (Q3W) or 2.25 mcg/kg darbepoetin alfa weekly (QW) for 15 weeks. A previously published report from this trial showed Q3W dosing was non-inferior to QW dosing for reducing transfusions from week 5 to end-of-the-treatment period (EOTP). In the present analysis, outcomes were reanalyzed by baseline Hb <10 g/dL and > or = 10 g/dL. Endpoints included transfusion rates, Hb outcomes, and safety profiles. RESULTS: This study reanalyzed 351 and 354 patients who initiated ESA therapy at a baseline Hb of <10 g/dL or > or = 10 g/dL, respectively. From week 5 to EOTP, the estimated Kaplan-Meier transfusion incidence (Q3W vs QW) was lower in the > or = 10 g/dL baseline-Hb group (14% vs 21%) compared with the <10 g/dL baseline-Hb group (36% vs 41%). By week 5, the > or = 10 g/dL baseline-Hb group, but not the <10 g/dL baseline-Hb group, achieved a mean Hb > or = 11 g/dL. The Kaplan-Meier estimate of percentage of patients (Q3W vs QW) who achieved Hb > or = 11 g/dL from week 1 to EOTP was 90% vs 85% in the > or = 10 g/dL baseline-Hb group and 54% vs 57% in the <10 g/dL baseline-Hb group. Both baseline-Hb groups maintained mean Hb levels <12 g/dL and had similar safety profiles, though more patients in the > or = 10 g/dL baseline-Hb group reached the threshold Hb of > or = 13 g/dL. CONCLUSION: In this exploratory analysis, darbepoetin alfa Q3W and QW raised Hb levels and maintained mean Hb at <12 g/dL in both baseline-Hb groups. The > or = 10 g/dL baseline-Hb group had fewer transfusions and faster anemia correction. Additional studies should prospectively evaluate the relationship between Hb levels at ESA initiation and outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00118638.

Transfusion risk in cancer patients with chemotherapy-induced anemia when initiating darbepoetin alfa therapy at a baseline hemoglobin level of <9 g/dL versus 9 to <10 g/dL versus ≥ 10 g/dL: an exploratory analysis of a phase 3 trial.

Darbepoetin alfa (DA) is an erythropoiesis-stimulating agent (ESA) approved for treating chemotherapy-induced anemia (CIA). Safety concerns have prompted changes to the ESA-product information, which now recommends initiating ESAs at hemoglobin (Hb) levels < 10 g/dL (US) or ≤ 10 g/dL (EU). The present exploratory analysis of a DA trial examined how baseline-Hb levels at ESA initiation affect transfusion rates, Hb response, and safety outcomes in CIA patients. Data were retrospectively analyzed from a phase 3 trial of CIA patients randomised to 500 mcg DA every 3 weeks (Q3 W) or to 2.25 mcg/kg DA weekly (QW) for 15 weeks. In the current analysis, data were reanalyzed by baseline-Hb categories of <9 g/dL (n = 126), 9 to <10 g/dL (n = 225), and ≥ 10 g/dL (n = 354). The Q3 W and QW groups were combined. Transfusion rates were highest in the <9 g/dL baseline-Hb group in all time periods examined. The Kaplan-Meier percentage (95% CI) of patients achieving Hb ≥ 10 g/dL was 68% (59, 78) and 88% (82, 92) in the <9 g/dL and 9 to <10 g/dL baseline-Hb groups, respectively. With lower baseline-Hb, incidence of a ≥ 1 g/dL-Hb rise in 14 days progressively decreased. Incidence of venous thromboembolic events was similar in all baseline-Hb groups and similar between patients with or without a ≥ 1 g/dL-Hb rise in 14 days. Overall, transfusion risk increased and Hb response decreased at lower baseline-Hb levels in this exploratory analysis. When following ESA-product information to initiate ESAs at Hb ≤ 10 g/dL, the greatest benefit may be achieved when initiating close to 10 g/dL. Prospective studies are needed to further examine this hypothesis.

Pooled analysis of individual patient-level data from all randomized, double-blind, placebo-controlled trials of darbepoetin alfa in the treatment of patients with chemotherapy-induced anemia.

PURPOSE: Although numerous clinical trials have demonstrated the efficacy and tolerability of erythropoiesis-stimulating agents (ESAs) in patients with chemotherapy-induced anemia (CIA), results of some recent trials and one meta-analysis have suggested that ESAs may negatively impact survival and/or disease control in patients with cancer. METHODS: To assess the benefits and risks of ESAs in CIA, we conducted a pooled analysis of individual patient-level data from all randomized, double-blind, placebo-controlled trials in 2,122 patients with CIA receiving darbepoetin alfa (DA; n = 1,200) or placebo (n = 912). RESULTS: DA did not increase mortality (hazard ratio = 0.97; 95% CI, 0.85 to 1.1) and had no effect on progression-free survival (hazard ratio = 0.93; 95% CI, 0.84 to 1.04) and disease progression (hazard ratio = 0.92; 95% CI, 0.82 to 1.03), but, as expected, increased the risk for thromboembolic events (hazard ratio = 1.57; 95% CI, 1.10 to 2.26). Overall and progression-free survival were not affected by baseline hemoglobin and seemed better in patients who achieved hemoglobin more than 12 or more than 13 g/dL. Transfusions and rates of hemoglobin increase (> 1 g/dL in 14 days; > 2 g/dL in 28 days) owing to transfusions were associated with an increased risk for death and disease progression in both treatment groups; in the absence of transfusions, rates of hemoglobin increase did not appear to increase the risk for adverse outcomes. Compared with placebo, DA significantly reduced the risk of receiving one or more transfusion. CONCLUSION: There seemed to be no association between DA and risk of death or disease progression in this meta-analysis of individual patient data from DA studies conducted in CIA, the approved indication for ESAs in oncology.