The effectiveness and cost-effectiveness of erythropoiesis-stimulating agents (epoetin and darbepoetin) for treating cancer treatment-induced anaemia (including review of technology appraisal no. 142): a systematic review and economic model

BACKGROUND

Anaemia is a common side effect of cancer treatments and can lead to a reduction in quality of life. Erythropoiesis-stimulating agents (ESAs) are licensed for use in conjunction with red blood cell transfusions to improve cancer treatment-induced anaemia (CIA).

OBJECTIVE

To investigate the effectiveness and cost-effectiveness of ESAs in anaemia associated with cancer treatment (specifically chemotherapy).

DATA SOURCES

The following databases were searched from 2004 to 2013: The Cochrane Library, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Web of Science, Cumulative Index to Nursing and Allied Health Literature, British Nursing Index, Health Management Information Consortium, Current Controlled Trials and ClinicalTrials.gov. The US Food and Drug Administration and European Medicines Agency websites were also searched. Bibliographies of included papers were scrutinised for further potentially includable studies.

REVIEW METHODS

The clinical effectiveness review followed principles published by the NHS Centre for Reviews and Dissemination. Randomised controlled trials (RCTs), or systematic reviews of RCTs, of ESAs (epoetin or darbepoetin) for treating people with CIA were eligible for inclusion in the review. Comparators were best supportive care, placebo or other ESAs. Anaemia- and malignancy-related outcomes, health-related quality of life (HRQoL) and adverse events (AEs) were evaluated. When appropriate, data were pooled using meta-analysis. An empirical health economic model was developed comparing ESA treatment with no ESA treatment. The model comprised two components: one evaluating short-term costs and quality-adjusted life-years (QALYs) (while patients are anaemic) and one evaluating long-term QALYs. Costs and benefits were discounted at 3.5% per annum. Probabilistic and univariate deterministic sensitivity analyses were performed.

RESULTS

Of 1457 titles and abstracts screened, 23 studies assessing ESAs within their licensed indication (based on start dose administered) were included in the review. None of the RCTs were completely aligned with current European Union licenses. The results suggest a clinical benefit from ESAs for anaemia-related outcomes and an improvement in HRQoL scores. The impact of ESAs on AEs and survival remains highly uncertain, although point estimates are lower, confidence intervals are wide and not statistically significant. Base-case incremental cost-effectiveness ratios (ICERs) for ESA treatment compared with no ESA treatment ranged from £ 19,429 to £ 35,018 per QALY gained, but sensitivity and scenario analyses demonstrate considerable uncertainty in these ICERs, including the possibility of overall health disbenefit. All ICERs were sensitive to survival and cost.

LIMITATIONS

The relative effectiveness of ESAs was not addressed; all ESAs were assumed to have equivalent efficacy. No studies were completely aligned with their European labelling beyond the starting dose evaluated. There is questionable generalisability given that the included trials were published >20 years ago and there have been many changes to chemotherapy as well as to the quality of supportive treatment. Trial quality was moderate or poor and there was considerable unexplained heterogeneity for a number of outcomes, particularly survival, and evidence of publication bias. Adjustments were not made to account for multiple testing.

CONCLUSIONS

ESAs could be cost-effective when used closer to licence, but there is considerable uncertainty, mainly because of unknown impacts on overall survival.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005812.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A prospective cohort study on the impact of darbepoetin alfa on quality of life in daily practice following anemia treatment guideline revisions

OBJECTIVE

This study aimed to evaluate the impact of darbepoetin alfa (DA) on hemoglobin (Hb) levels and quality of life (QoL) in cancer patients with anemia in current daily practice following several revisions of anemia treatment guidelines.

METHODS

This was a prospective, multi-center, observational study across Germany in non-myeloid cancer outpatients with chemotherapy-induced anemia treated with DA. Age, sex, cancer type, stage, and therapy, performance status, anemia status and treatment, and Hb concentrations were recorded for up to 18 weeks in a web-based registry. Optional QoL assessments were collected at baseline and at the end of DA treatment.

MAIN RESULTS

Of 984 eligible patients, 978 had complete anemia data, 492 also had complete QoL data. In the 978 patients, mean age was 64 (standard deviation, SD 12) years, 62% of patients were women. Breast (26%) and gastrointestinal (22%) cancer were most prevalent. Therapy was palliative in 44% of patients and initiated with curative intent in 29%. Mean baseline Hb was 9.5 (SD 0.9) g/dL, which increased by an average of 1.2 g/dL. In 67% of patients Hb increased either to 10-12 g/dL or by ≥2 g/dL; no Hb response was seen in 219 patients (22%); increases of 0 to 1, >1 to 2, and >2 g/dl were seen in 216 (22%), 265 (27%), and 278 (28%) patients, respectively. Anemia treatment did not result in any significant differences of performance status. However, QoL improvements were significantly greater in Hb responders, although a linear relationship with Hb increments was lacking. None of 47 fatal cases was considered related to treatment with DA.

CONCLUSION

Patients treated with DA in routine clinical practice had increases in Hb and reported improvement in QoL. Due to the uncontrolled design, no conclusions can be made regarding causality to treatment and the clinical relevance of the improvement.

Pharmacovigilance in practice: erythropoiesis-stimulating agents

Pharmacovigilance (PV) is the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or other problems related to medical products after they have been licensed for marketing. The purpose of PV is to advance the safe use of marketed medical products. Regulatory agencies and license holders collaborate to collect data reported by health care providers, patients, and the public as well as data from systematic reviews, meta-analyses, and individual clinical and nonclinical studies. They validate and analyze the data to determine whether safety signals exist, and if warranted, develop an action plan to mitigate the identified risk. Erythropoiesis-stimulating agents (ESAs) provide an example of how PV is applied in reality. Among other approved indications, ESAs may be used to treat anemia in patients with chemotherapy-induced anemia. ESAs increase hemoglobin levels and reduce the need for transfusions; they are also associated with a known increased risk of thromboembolic events. Starting in 2003, emerging data suggested that ESAs might reduce survival. As a result of PV activities by regulatory agencies and license holders, labeling for ESAs addresses these risks. Meta-analyses and individual clinical studies have confirmed that ESAs increase the risk of thromboembolic events, but when used as indicated, ESAs have not been shown to have a significant effect on survival or disease progression. Ongoing safety studies will provide additional data in the coming years to further clarify the risks and benefits of ESAs.

Prognostic impact of the combination of erythropoiesis-stimulating agents to cancer treatment: literature review

Cancer patients commonly develop anaemia. Erythropoiesis-stimulating agents (ESAs) are frequently used in cancer treatment. Numerous controlled studies indicate that ESAs can raise haemoglobin levels, reduce transfusion requirements and improve quality of life in anaemic cancer patients receiving chemotherapy. They were previously used to enhance response to radiation therapy, via increasing tumour cell oxygenation. Since the 2002 guideline, there has been increasing attention to the safety of ESA treatment in patients with cancer. Two placebo-controlled phase III randomised clinical trials published in 2003 showed evidence of harmful effects of ESAs on survival and/or tumour outcomes. Subsequently, recent trials and several large meta-analyses have confirmed negative impact on survival and/or disease progression. To comprehensively examine whether ESA use affects safety outcomes in cancer patients in different settings (chemotherapy, radiotherapy and targeted therapies), we conducted a literature review of all clinical trials, small and large meta-analyses from 1990 to 2012.

Chemotherapy-induced anemia: the story of darbepoetin alfa

BACKGROUND

Prior to the approval of the first erythropoiesis-stimulating agent (ESA) in the early 1990s, red blood cell transfusions were the primary means of treating severe chemotherapy-induced anemia (CIA), with little recourse for those with more mild forms of the condition. The introduction of the ESAs allowed treatment of mild-to-moderate CIA in patients with cancer. It has been a decade since darbepoetin alfa (DA), a second-generation ESA with a longer half-life, became available to patients with CIA.

OBJECTIVE AND METHODS

We present a review of studies on DA in CIA, from its development through to the present day. Medline was searched for randomized clinical trials on DA. Additional trials and meta-analyses on ESAs were incorporated into this review when relevant.

RESULTS

The first publications on DA generally focused on optimal dosing, efficacy and tolerability. In these, it was shown that DA is an effective and well tolerated treatment option to achieve hematopoietic response, regardless of dosing interval. Subsequently, the focus shifted towards meta-analyses on survival data of all ESAs. These reported conflicting results regarding mortality and/or disease progression. However, guidelines for ESA use were updated and, when followed, these make ESAs a well tolerated and effective tool for managing CIA.

CONCLUSIONS

As the past decade has broadened our knowledge on the benefits and risks of CIA management, continued high-quality studies will help to optimize treatment with ESAs in order to maximize quality of life for these patients. The limitation of a literature review of this nature is the complete reliance on previously published research and the availability of these studies using the methodology outlined above.

Darbepoetin alfa in the treatment of anemia in cancer patients undergoing chemotherapy

For years, the treatment of chemotherapy-induced anemia (CIA) consisted of red blood cell transfusions. Major disadvantages of transfusions are their temporary effect and limitation to treatment of severe anemia. In an extensive clinical trial program in patients with CIA, darbepoetin alfa (DA) - a long-acting recombinant human erythropoietin - was proven to be very effective in reducing transfusion needs in patients developing CIA. The administration is suitable with most chemotherapy schemes. Caution is needed in patients with a history of thrombo-embolic events, as a slightly higher incidence of these events is noted in patients treated with darbepoetin alfa or erythropoietin substitution agents (ESAs) in general. In recent years, concerns have been raised about a potential negative influence of these agents on survival. In this respect, it is important to make the distinction between studies on the treatment of existing CIA versus treatment with ESAs outside this indication. On the other hand, it has always been assumed that transfusions were a completely safe treatment, but concerns about a potential negative effect on survival have been raised for transfusions as well. The safety concerns with DA and ESAs in general led to a pharmacovigilance program and an adaptation of the guidelines for treatment of CIA, focusing on treatment of moderate CIA but no longer on mild CIA. Now that the most recent safety data of the pharmacovigilance program of ESAs is almost completed, the clinical impact of the shift to the treatment of only moderate anemia is discussed in this review, which provides a critical view on the indications of DA and the benefit-risk assessment, in order to provide good supportive care without harm to the patient.

Effects of erythropoiesis-stimulating agents on survival and other outcomes in patients with lymphoproliferative malignancies: a study-level meta-analysis

Erythropoiesis-stimulating agents (ESAs) are approved to treat anemia in patients with non-myeloid malignancies receiving myelosuppressive chemotherapy. ESAs reduce transfusion rates, but some clinical studies suggest that ESAs may reduce survival or increase disease progression. This study-level meta-analysis examined the effects of darbepoetin alfa, epoetin alfa or epoetin beta on mortality, disease progression and transfusion incidence in patients with lymphoproliferative malignancies, using randomized, controlled trials of patients receiving chemotherapy and ESAs or standard of care. The odds ratio (OR) for mortality was 1.04 (95% confidence interval [CI], 0.81-1.34, random-effects model, 10 studies); the risk difference was - 0.01 (95% CI, - 0.03-0.02). The OR for disease progression was 1.02 (95% CI 0.81-1.30, random-effects model, five studies). A lower proportion of ESA-treated patients than controls received transfusions (seven studies). In this meta-analysis, ESAs reduced transfusions with no clear effect on mortality or disease progression in patients with lymphoproliferative malignancies receiving chemotherapy.

Effects of erythropoietin receptors and erythropoiesis-stimulating agents on disease progression in cancer

Erythropoiesis-stimulating agents (ESAs) increase red blood cell (RBC) production in bone marrow by activating the erythropoietin receptor (EpoR) on erythrocytic-progenitor cells. Erythropoiesis-stimulating agents are approved in the United States and Europe for treating anaemia in cancer patients receiving chemotherapy based on randomised, placebo-controlled trials showing that ESAs reduce RBC transfusions. Erythropoiesis-stimulating agent-safety issues include thromboembolic events and concerns regarding whether ESAs increase disease progression and/or mortality in cancer patients. Several trials have reported an association between ESA use and increased disease progression and/or mortality, whereas other trials in the same tumour types have not provided similar findings. This review thoroughly examines available evidence regarding whether ESAs affect disease progression. Both clinical-trial data on ESAs and disease progression, and preclinical data on how ESAs could affect tumour growth are summarised. Preclinical topics include (i) whether tumour cells express EpoR and could be directly stimulated to grow by ESA exposure and (ii) whether endothelial cells express EpoR and could be stimulated by ESA exposure to undergo angiogenesis and indirectly promote tumour growth. Although assessment and definition of disease progression vary across studies, the current clinical data suggest that ESAs may have little effect on disease progression in chemotherapy patients, and preclinical data indicate a direct or indirect effect of ESAs on tumour growth is not strongly supported.