Current practice of darbepoetin alfa in the management of haemoglobin levels in cancer patients undergoing chemotherapy - data from the CHOICE study

APPLY: A prospective observational study of clinical practice patterns of darbepoetin alfa use in patients with chemotherapy-induced anemia in Romania

Purpose

The primary objective of this study was to evaluate the compliance of Romanian physicians with the national therapeutic protocol and international guidelines on treatment with erythropoiesis-stimulating agents in anemic cancer patients receiving chemotherapy. The secondary objective was to assess the hemoglobin (Hb) level change due to anemia treatment and safety of darbepoetin alfa.

Methods

This was a single-arm, prospective, longitudinal, multicenter, observational study in patients with nonmyeloid malignancies and symptomatic chemotherapy-induced anemia treated concomitantly with darbepoetin alfa. Patients were followed for the duration of chemotherapy, but no shorter than three and no longer than eight cycles, irrespective of their exposure to darbepoetin alfa.

Results

In this study, 497 patients with a mean age of 60.6 years were analyzed. Most patients (80.7%) were initiated on darbepoetin alfa at a Hb of 9–11 g/dL, congruent with recommendations. The median Hb increased by 0.9 g/dL between baseline and week 12. Hb target achievement was higher among patients treated according to guidelines than those initiated at Hb < 9 g/dL. A similar trend was observed for red blood cell transfusion requirements. No new safety signals were reported for darbepoetin alfa.

Conclusions

The majority of patients were treated according to national and international recommendations. Guideline adherence was associated with more frequent achievement of Hb targets and lower red blood cell transfusion requirements compared with patients starting anemia treatment with darbepoetin alfa at lower-than-recommended Hb levels.

Electronic supplementary material

The online version of this article (10.1007/s12254-018-0390-4) contains supplementary material, which is available to authorized users.

Effectiveness of Darbepoetin Alfa for Chemotherapy-induced Anemia When Initiated at Hemoglobin ≤10 g/dL

PURPOSE

Limited data are available to describe the effectiveness of darbepoetin alfa (DA) in terms of hemoglobin (Hb) and transfusion outcomes when initiated at Hb ≤10 g/dL (the threshold specified in the summary of prescribing characteristics). We assessed DA, initiated according to current labeling (Hb ≤10 g/dL), in chemotherapy-induced anemia (CIA).

METHODS

Data for patients with cancer and CIA who initiated DA at Hb ≤10 g/dL were extracted from a database of Amgen-sponsored trials. A comparative analysis was limited to randomized, controlled trials in patients treated with DA or control (placebo/best supportive care). Data for the DA arm(s) of randomized, multiple-arm, or prospective, single-arm trials were also extracted (DA-only analysis; non-front-loaded studies only). Outcomes included Hb increase ≥1 g/dL or ≥2 g/dL during the first 12 weeks of treatment. Crude and Kaplan-Meier proportions of patients who experienced each outcome and time (days) to each outcome were summarized by treatment arm. Meta-analysis (fixed-effects inverse-variance method) was performed to compare outcomes for DA with control.

FINDINGS

The comparative analysis included 4 studies (2 in lung cancer, 1 in lymphoproliferative disease, and 1 in non-myeloid malignancy: DA, n = 261; control, n = 273). The DA-only analysis included 15 studies (n = 3768). In comparative analyses, more patients who received DA than placebo achieved Hb increase of ≥1 g/dL (fixed-effects hazard ratio [HR] = 2.07; 95% CI, 1.62-2.63) or ≥2 g/dL (HR = 2.91; 95% CI, 2.09-4.06). Median times to ≥1 g/dL or ≥2 g/dL increase were 43 or 78 days for DA (not evaluable for placebo). Transfusions were less common in patients who received DA (HR = 0.58; 95% CI, 0.44-0.77). Addition of 2 dose-finding studies did not change the findings of the main comparative analysis. Results were similar in the DA-only analyses.

IMPLICATIONS

This is the first patient-level meta-analysis, to our knowledge, to evaluate the efficacy in terms of Hb response of DA treatment when initiated according to current product labeling in patients with CIA. Limitations include the small number of studies and patients eligible for inclusion in the comparative analyses and the absence of non-Amgen trials of DA. The results of the comparative analysis confirm that DA is more effective than placebo at increasing serum Hb levels and at reducing the need for transfusion in patients with CIA when treatment is initiated at Hb ≤10 g/dL, as per current product labeling.

Erythropoietin and cancer: the unintended consequences of anemia correction

Until 1990, erythropoietin (EPO) was considered to have a single biological purpose and action, the stimulation of red blood cell growth and differentiation. Slowly, scientific and medical opinion evolved, beginning with the discovery of an effect on endothelial cell growth in vitro and the identification of EPO receptors (EPORs) on neuronal cells. We now know that EPO is a pleiotropic growth factor that exhibits an anti-apoptotic action on numerous cells and tissues, including malignant ones. In this article, we present a short discussion of EPO, receptors involved in EPO signal transduction, and their action on non-hematopoietic cells. This is followed by a more detailed presentation of both pre-clinical and clinical data that demonstrate EPO’s action on cancer cells, as well as tumor angiogenesis and lymphangiogenesis. Clinical trials with reported adverse effects of chronic erythropoiesis-stimulating agents (ESAs) treatment as well as clinical studies exploring the prognostic significance of EPO and EPOR expression in cancer patients are reviewed. Finally, we address the use of EPO and other ESAs in cancer patients.

A final analysis from the CHOICE study examining darbepoetin alfa use for chemotherapy-induced anaemia in current European clinical practice

OBJECTIVES

The CHOICE study was a prospective, multicentre, observational study designed to assess the level of adherence in current clinical practice to the European product label and the EORTC guidelines for the treatment of chemotherapy-induced anaemia with darbepoetin alfa (DA).

METHODS

Hb levels and red blood cell (RBC) transfusion requirements were evaluated among 1900 patients with solid tumours in 11 European countries. The primary outcome measure was the proportion of patients with a target Hb level of ≥10-≤12 g/dL after 9 weeks' DA treatment.

RESULTS

The full analysis set (FAS) comprised 1887 patients (mean ± SD age 62.4 ± 11.4 years) divided into categories by baseline Hb < 9 g/dL (n = 281); 9-<10 g/dL (n = 770); 10-<11 g/dL (n = 695); ≥11 g/dL (n = 114). The proportion of patients who remained on the study at week 9 achieving the target Hb level was 37% (n = 60), 48% (n = 217), 54% (n = 210) and 38% (n = 23) in the subgroups with a baseline Hb level of <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL, respectively. In the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups of the FAS, the number of patients maintaining Hb levels ≥10 g/dL after their first achievement of an Hb value of 10 g/dL was 95 (34%), 372 (48%), 476 (68%) and 87 (76%), respectively. The Kaplan-Meier percentages of patients who required an RBC transfusion from week 5 until end of treatment period were: 29%, 20%, 12% and 17% in the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups, respectively. Kaplan-Meier percentages of patients reaching an Hb level of >13 g/dL were 10%, 9%, 21% and 29%, respectively. Potential bias could not be excluded due to the study's observational nature.

CONCLUSIONS

DA initiation and target Hb ranges adhered to current guidelines in the majority of patients. Furthermore, this study demonstrates faster achievement of the target range and reduced transfusion requirements are associated with initiation of DA at Hb levels of 9-<10 g/dL and 10-<11 g/dL rather than <9 g/dL.