Assessing the effect of darbepoetin alfa on patient-reported fatigue in chemotherapy-induced anemia in four randomized, placebo-controlled clinical trials.

PURPOSE: This analysis examined the effects of darbepoetin alfa on hemoglobin and fatigue outcomes in patients with cancer using latent growth curve modeling (LGM).
METHODS: Data from 4 clinical trials of darbepoetin alfa in lung cancer (2 studies; n = 547; n = 288), lymphoproliferative malignancies (n = 339), and non-myeloid malignancies (n = 320) were analyzed separately. Fatigue was assessed using the FACT-Fatigue (FACT-F) scale. Effects of darbepoetin alfa on changes in hemoglobin and FACT-F scores were evaluated using LGM, controlling for age, gender, Eastern Cooperative Oncology Group performance status, health status, and total transfusions.
RESULTS: Patients receiving darbepoetin alfa had higher rates of change in hemoglobin (standardized regression coefficient [[Formula: see text]] = 0.30 to 0.53, all P < 0.05) than placebo. Patients with greater rates of change in hemoglobin reported improvements in fatigue outcomes ([Formula: see text] = 0.28 to 0.59, all P < 0.05). The total standardized effect of darbepoetin alfa on fatigue outcomes corresponded to a mean change of 0.9 to 3.5 points in FACT-F scores, with one trial demonstrating changes exceeding the minimal important difference of 3 points.
CONCLUSIONS: Darbepoetin alfa improved hemoglobin which was associated with improved fatigue across the 4 trials. Clinically, meaningful improvement in fatigue was seen in 2 trials. More complex statistical analysis models of treatment may assist in understanding the effects of erythropoiesis-stimulating agents on patient-reported outcomes.