Venous thromboembolism and mortality associated with recombinant erythropoietin and darbepoetin administration for the treatment of cancer-associated anemia

Clinical outcomes with use of erythropoiesis stimulating agents in patients with the HeartMate II left ventricular assist device

OBJECTIVES

This study evaluated clinical outcomes associated with erythropoiesis stimulating agent (ESA) use in left ventricular assist devices (LVAD)-supported patients.

BACKGROUND

Use of ESAs in patients with LVADs may minimize blood transfusions and decrease allosensitization. ESAs increase thrombotic events, which is concerning because LVADs are sensitive to pump thrombosis (PT).

METHODS

We retrospectively reviewed 221 patients at our center who received a HeartMate II (Thoratec Corp., Pleasanton, California) LVAD between January 1, 2009 and June 6, 2013. Patients were divided into those who received ESAs during index admission (n = 121) and those who did not (n = 100). Suspected PT was defined as evidence of thrombus in the LVAD or severe hemolysis (lactate dehydrogenase >1,000 mg/dl or plasma-free hemoglobin >40 mg/dl). Outcomes were compared between cohorts using inverse probability-weighted analyses.

RESULTS

During a mean follow-up of 14.2 ± 11.9 months, suspected PT occurred in 37 patients (ESA 23%, no ESA 12%; p =0.03). The ESA cohort received ESAs 13.9 ± 60.9 days after LVAD implantation. At 180 days, event-free rates for suspected PT were ESA 78.6% versus no ESA 94.5% (p < 0.001). ESA use had higher rates of suspected PT (hazard ratio [HR]: 2.35; 95% confidence interval [CI]: 1.38 to 4.00; p = 0.002). For every 100-unit increase in cumulative ESA dosage, the hazard of suspected PT increased by 10% (HR: 1.10; 95% CI: 1.04 to 1.16; p < 0.001). After inverse probability weighting, ESA use was associated with a significantly higher rate of all-cause mortality (HR: 1.62; 95% CI: 1.12 to 2.33; p = 0.01).

CONCLUSIONS

ESA use in LVAD patients is associated with higher rates of suspected PT.

Two-step purification procedure for recombinant human asialoerythropoietin expressed in transgenic plants

Asialoerythropoietin (asialo-EPO) is a desialylated form of human glycoprotein hormone erythropoietin (EPO), which has been reported to be neuro-, cardio-, and renoprotective in animal models of organ injuries. Since the current method of production of asialo-EPO from mammalian cell-made recombinant human EPO (rhuEPO(M)) by enzymatic desialylation is not commercially viable, we and others used plant-based expression systems to produce recombinant human asialo-EPO (asialo-rhuEPO(P)). Despite achieving high expression levels in plants, its purification from plant extracts has remained a greater challenge, which has prevented studying its tissue-protective effects and translating it into clinical practice. In this study, a procedure was developed to purify asialo-rhuEPO(P) from transgenic tobacco leaf tissues in two steps: ion-exchange chromatography based on its high pI (8.75) to separate it from acidic plant proteins, and immunoaffinity chromatography to obtain pure asialo-rhuEPO(P). Using this process, up to 31% of the asialo-rhuEPO(P) could be recovered to near homogeneity from plant extracts. This work demonstrates that asialo-rhuEPO(P) expressed in tobacco plants could be purified in high yield and purity using minimal steps, which might be suitable for scale-up. Furthermore, the ion-exchange chromatography step together with the use of protein-specific antibody column could be used to purify a wide variety of basic recombinant proteins from transgenic leaf tissues.

Effect of erythropoiesis-stimulating agent policy decisions on off-label use in myelodysplastic syndromes

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) are widely used to treat anemia associated with myelodysplastic syndromes (MDS) as an off-label indication. In early 2007, the U.S. Food and Drug Administration (FDA) released safety alerts and mandated label changes, and the Centers for Medicare & Medicaid Services (CMS) implemented a National Coverage Determination (NCD) in August 2007, dramatically restricting ESA coverage based on specific clinical parameters in non-MDS patients. We sought to determine the effect on ESA use in MDS, examining both treatment initiation and concordance with guidelines designed to target patients most likely to benefit from therapy.

METHODS

We determined receipt of ESA within 6 months of diagnosis. For ESA recipients, we operationalized three National Comprehensive Cancer Network guidelines: serum erythropoietin determination before ESA initiation, transfusion-independent at ESA initiation, and initial ESA treatment episode of >= 8 weeks. Logistic regression models tested the effect of time (half-year increments pre-post the August '07 CMS NCD implementation), controlling for demographics and health status.

RESULTS

17,491 (61.1%) of 28,627 beneficiaries with MDS received ESAs. ESA use increased prior to the reference period (Jan.-July 2007), but declined beginning in August 2007, the date of NCD implementation (marginal probability =-0.05, p-value<0.01). Concordance with treatment guidelines changed during the observation period, with increased rates of serum erythropoietin levels, but declined in the other two guidelines.

CONCLUSION

These results suggest a mixed pattern of change in the face of the FDA safety warnings and CMS NCD in MDS and highlight the importance of monitoring for unintended consequences of policy changes.

Regulatory and clinical considerations for biosimilar oncology drugs

Biological oncology products are integral to cancer treatment, but their high costs pose challenges to patients, families, providers, and insurers. The introduction of biosimilar agents-molecules that are similar in structure, function, activity, immunogenicity, and safety to the original biological drugs-provide opportunities both to improve health-care access and outcomes, and to reduce costs. Several international regulatory pathways have been developed to expedite entry of biosimilars into global marketplaces. The first wave of oncology biosimilar use was in Europe and India in 2007. Oncology biosimilars are now widely marketed in several countries in Europe, and in Australia, Japan, China, Russia, India, and South Korea. Their use is emerging worldwide, with the notable exception of the USA, where several regulatory and cost barriers to biosimilar approval exist. In this Review, we discuss oncology biosimilars and summarise their regulatory frameworks, clinical experiences, and safety concerns.

Red cell distribution width and other red blood cell parameters in patients with cancer: association with risk of venous thromboembolism and mortality

Background

Cancer patients are at high risk of developing venous thromboembolism (VTE). Red cell distribution width (RDW) has been reported to be associated with arterial and venous thrombosis and mortality in several diseases. Here, we analyzed the association between RDW and other red blood cell (RBC) parameters with risk of VTE and mortality in patients with cancer.

Methods

RBC parameters were measured in 1840 patients with cancers of the brain, breast, lung, stomach, colon, pancreas, prostate, kidney; lymphoma, multiple myeloma and other tumor sites, that were included in the Vienna Cancer and Thrombosis Study (CATS), which is an ongoing prospective, observational cohort study of patients with newly diagnosed or progressive cancer after remission. Primary study outcome is occurrence of symptomatic VTE and secondary outcome is death during a maximum follow-up of 2 years.

Results

During a median follow-up of 706 days, 131 (7.1%) patients developed VTE and 702 (38.2%) died. High RDW (>16%) was not associated with a higher risk of VTE in the total study cohort; in competing risk analysis accounting for death as competing variable the univariable subhazard ratio (SHR) was 1.34 (95% confidence interval [CI]: 0.80–2.23, p = 0.269). There was also no significant association between other RBC parameters and risk of VTE. High RDW was associated with an increased risk of mortality in the total study population (hazard ratio [HR, 95% CI]: 1.72 [1.39–2.12], p<0.001), and this association prevailed after adjustment for age, sex, hemoglobin, leukocyte and platelet count (HR [95% CI]: 1.34 [1.06–1.70], p = 0.016).

Conclusions

RDW and other RBC parameters were not independently associated with risk of VTE in patients with cancer and might therefore not be of added value for estimating risk of VTE in patients with cancer. We could confirm that high RDW is an independent predictor of poor overall survival in cancer.

Risk of treatment-related deaths with vascular endothelial growth factor receptor tyrosine kinase inhibitors: a meta-analysis of 41 randomized controlled trials

Background

Vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) have widely been used in advanced cancer. However, these drugs may also lead to serious adverse events. The present meta-analysis aimed to determine the overall incidence and risk of deaths due to VEGFR-TKIs with more detailed subgroup analysis.

Materials and methods

PubMed, Web of Science, and Cochrane databases were searched for randomized controlled trials (RCTs) that compared VEGFR-TKIs with non-VEGFR-TKIs in the treatment of solid cancer. Pooled incidence, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects or fixed-effects models based on the heterogeneity of included trials.

Results

A total of 14,139 participants from 41 RCTs were enrolled. The pooled incidence of death due to VEGFR-TKIs was 1.9% (95% CI: 1.6%–2.3%) with an OR of 1.85 (95% CI: 1.33–2.58; P<0.01) when compared with control groups. On subgroup analysis, significantly increased risk of death was found in patients with nonsmall-cell lung cancer (OR: 2.37; 95% CI: 1.19–4.73; P=0.01) and colorectal cancer (OR: 2.84; 95% CI: 1.02–7.96; P=0.05). Among different VEGFR-TKIs, sorafenib and sunitinib had significant risk of death when compared with control arms, respectively. VEGFR-TKIs in combination with other antineoplastic agents, but not VEGFR-TKI monotherapy, significantly increased the risk of treatment-related deaths. No heterogeneity was noted across all the prespecified subgroups regarding ORs.

Conclusion

The present work pointed out a significantly increased risk of death due to VEGFR-TKIs. Close monitoring should be emphasized in patients receiving these drugs.

Aspirin Increases the Risk of Venous Thromboembolism in Surgical Patients

The risk of venous thromboembolism (VTE) for patients taking an antiplatelet agent is largely unknown. This study aimed to investigate the association between antiplatelet agent use before admission with the risk of in-hospital VTE in surgical intensive care unit (ICU) patients. A retrospective review of all patients admitted to the surgical ICU at a Level I trauma center over 30 months was performed. Patients who underwent diagnostic imaging for VTE were selected. Patients were divided based on whether or not antiplatelet agents were used before admission (APTA vs NAPTA). The primary outcome was VTE occurrence. A forward logistic regression model was used to identify factors independently associated with the primary outcome. During the study period, 461 (24%) patients met inclusion criteria: 70 (15%) APTA and 391 (85%) NAPTA. After adjusting for confounding factors, APTA patients were at a significantly higher risk for developing VTE (59 vs 40%; adjusted odds ratio, 1.8; 95% confidence interval, 1.0 to 3.0; adjusted P = 0.04). Whether or not antiplatelet agents were resumed during the hospital stay and the day on which they were resumed did not affect VTE risk. In conclusion, surgical ICU patients receiving antiplatelet agents before admission are at a significantly higher risk for development of VTE.

Erythropoiesis stimulating agents and clinical outcomes of invasive breast cancer patients receiving cytotoxic chemotherapy

The use of erythropoiesis stimulating agents (ESAs) to treat anemia in breast cancer patients who are treated with chemotherapy is a matter of ongoing debate. Several recent randomized trials challenged conventional wisdom, which holds that ESAs are contraindicated for breast cancer patients undergoing curative treatment. We aimed to perform the first large national population-based study to analyze the association between ESA use and breast cancer patient outcomes. Cytotoxic chemotherapy-treated invasive breast cancer patients were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Non-ESA users were sequentially 1:1 matched to 2,000 randomly sampled ESA users on demographics (age, diagnosis year, race, marital status, and socioeconomic status), tumor presentation (stage, grade, and status of hormone receptors), and treatments (surgery, radiation, and sub-types of chemotherapy) using a minimum distant strategy. Breast cancer-specific survival of ESA and matched non-ESA users was compared using Fine and Gray competing risk model. Compared to ESA users, non-ESA users exhibited dramatically different baseline characteristics such as less advanced tumor, and fewer co-morbidities. Non-ESA users had a significantly more favorable breast cancer-specific survival (subdistribution hazard ratio [sHR] = 0.75, p < 0.0001). This survival disparity was progressively diminished in the sequential matching of demographics (sHR = 0.74, p = 0.0004), presentation (sHR = 0.86, p = 0.06), and treatment (sHR = 0.89, p = 0.17) variables. Stratified analyses identified subgroups of patients whose breast cancer-specific survival were not different between ESA and non-ESA users. In the SEER-Medicare database, ESA usage does not seem to be associated with unfavorable breast cancer-specific survival in breast cancer patients receiving cytotoxic chemotherapy. The ESA-breast cancer prognosis association is complex and requires more intensive investigations.

In-vivo detection of the erythropoietin receptor in tumours using positron emission tomography

OBJECTIVE

Recombinant human erythropoietin (rhuEpo) is used clinically to treat anaemia. However, rhuEpo-treated cancer patients show decreased survival rates and erythropoietin receptor (EpoR) expression has been found in patient tumour tissue. Thus, rhuEpo application might promote EpoR(+) tumour progression. We therefore developed the positron emission tomography (PET)-probe (68)Ga-DOTA-rhuEpo and evaluated its performance in EpoR(+) A549 non-small-cell lung cancer (NSCLC) xenografts.

METHODS

(68)Ga-DOTA-rhuEpo was generated by coupling DOTA-hydrazide to carbohydrate side-chains of rhuEpo. Biodistribution was determined in tumour-bearing mice 0.5, 3, 6, and 9 h after probe injection. Competition experiments were performed by co-injecting (68)Ga-DOTA-rhuEpo and rhuEpo in five-fold excess. Probe specificity was further evaluated histologically using Epo-Cy5.5 stainings.

RESULTS

The blood half-life of (68)Ga-DOTA-rhuEpo was 2.6 h and the unbound fraction was cleared by the liver and kidney. After 6 h, the highest tumour to muscle ratio was reached. The highest (68)Ga-DOTA-rhuEpo accumulation was found in liver (10.06 ± 6.26%ID/ml), followed by bone marrow (1.87 ± 0.53%ID/ml), kidney (1.58 ± 0.39%ID/ml), and tumour (0.99 ± 0.16%ID/ml). EpoR presence in these organs was histologically confirmed. Competition experiments showed significantly (p < 0.05) lower PET-signals in tumour and bone marrow at 3 and 6 h.

CONCLUSION

(68)Ga-DOTA-rhuEpo shows favourable pharmacokinetic properties and detects EpoR specifically. Therefore, it might become a valuable radiotracer to monitor EpoR status in tumours and support decision-making in anaemia therapy.

KEY POINTS

• PET-probe (68) Ga-DOTA-rhuEpo was administered to assess the EpoR status in vivo • (68) Ga-DOTA-rhuEpo binds specifically to EpoR positive organs in vivo • Tumour EpoR status determination might enable decision-making in anaemia therapy with rhuEpo.

Diabetes mellitus and advanced liver fibrosis are risk factors for severe anaemia during telaprevir-based triple therapy

BACKGROUND & AIMS

Adding telaprevir to pegylated-interferon and ribavirin increased both response rates and side effects of hepatitis C virus (HCV) treatment. We identified variables associated with severe anaemia during telaprevir-based triple therapy.

METHODS

An observational study was performed on 142 HCV-infected patients between June 2011 and March 2012. All subjects completed 12 weeks of telaprevir-based triple therapy or discontinued early because of anaemia. Severe anaemia was defined by a haemoglobin≤8.9 g/dl; advanced fibrosis was determined by Fib-4≥3.25.

RESULTS

The 47 (33%) patients who developed severe anaemia were similar to those who did not in sex, race, and prior response to dual therapy, but they were more likely to have diabetes (23.4% vs. 6.3%, P<0.01), advanced fibrosis (46.8% vs. 29.5%, P=0.04) and a history of anaemia during previous dual therapy (29.7% vs. 11.4%, P=0.02). Patients developing severe anaemia were older (59 vs. 56 years, P=0.02), had lower baseline platelet counts (134 vs. 163×10(9) /L, P=0.04), haemoglobin (14.0 vs. 15.0 g/dl, P<0.01), estimated glomerular filtration rate (79 vs. 90 ml/min/1.73 m2, P=0.03) and a higher median ribavirin/weight ratio (14.9 vs. 13.2 mg/kg, P<0.01). In multivariable logistic regression, presence of diabetes (OR=5.61, 95% CI: 1.59-19.72), Fib-4≥3.25 (OR=3.09, 95% CI: 1.28-7.46), higher ribavirin/weight ratio (OR=1.31 per mg/kg, 95% CI: 1.13-1.52) and lower baseline haemoglobin (OR=0.57 per g/dl, 95% CI, 0.41-0.80) were independently associated with developing severe anaemia.

CONCLUSIONS

Severe anaemia occurred in one-third of patients receiving telaprevir-based triple therapy. Risk was greater in patients with diabetes, advanced liver fibrosis, higher ribavirin/weight ratio and lower baseline haemoglobin.

Clostridium difficile increases the risk for venous thromboembolism

BACKGROUND

Inflammatory bowel disease is associated with a higher risk for venous thromboembolism (VTE). Whether Clostridium difficile infection similarly increases this risk is unknown.

METHODS

This was a retrospective analysis of patients admitted to the surgical intensive care unit (ICU) at the Cedars-Sinai Medical Center from February 2011 to July 2013. The 2 groups were compared using standard statistical methodology.

RESULTS

During the 30-month study period, a total of 1,728 patients were admitted to the surgical ICU. A total of 64 patients (3.7%) tested positive for C. difficile. The use of chemical prophylaxis for VTE was significantly higher in the C. difficile group (64.1% vs 46.2%, P = .005). Nonetheless, C. difficile patients had a higher risk for development of a VTE (23.4% vs 11.0%, adjusted odds ratio [95% confidence interval]: 1.87 [1.01 to 3.48], P = .048). In a forward logistic regression model, C. difficile was found to be independently associated with the development of VTE (adjusted odds ratio [95% confidence interval]: 1.87 [1.00 to 3.47], P = .049).

CONCLUSIONS

C. difficile infection increases the risk for VTE in surgical patients admitted to the ICU.

Erythropoiesis-stimulating agents in the management of cancer patients with anemia: a meta-analysis

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) are widely used in the management of anemia in cancer patients. Despite their apparent effectiveness, recent studies have suggested that ESAs could result in serious adverse events and even higher mortality. The aim of the current study was to evaluate the benefits and risks of ESAs in the management of cancer patients with anemia using a meta-analysis.

METHODS

The initial literature search covered Medline, PubMed, Embase, and the Cochrane Center Register of Controlled Trials, and identified 1,569 articles. The final meta-analysis included eight randomized controlled trials (n=2,387) in cancer patients with <11 g/dL hemoglobin (Hb) at the baseline and target Hb (for stopping ESA treatment) at no more than 13 g/dL. The assessment measures included Hb response, blood transfusion rate and adverse events that included venous thromboemblism (VTE), hypertension, and on-study mortality. The results are expressed as pooled odds ratio (OR). Publication bias was assessed using funnel plot analysis.

RESULTS

ESAs significantly increased the Hb concentration [OR 7.85, 95% confidence interval (CI): 5.85 to 10.53, P<0.001] and reduced the red blood cell (RBC) transfusion rate (OR 0.52, 95% CI: 0.42 to 0.65, P<0.001). ESAs did not increase the accumulated adverse events (OR 0.95, P=0.82), or the on-study mortality (OR 1.09, P=0.47).

CONCLUSIONS

ESAs are not associated with increased frequency of severe adverse events in anemic cancer patients when the target Hb value is no more than 13 g/dL.

Effects of erythropoiesis-stimulating agents on fatigue- and anaemia-related symptoms in cancer patients: systematic review and meta-analyses of published and unpublished data

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) reduce the need for red blood cell transfusions; however, they increase the risk of thromboembolic events and mortality. The impact of ESAs on quality of life (QoL) is controversial and led to different recommendations of medical societies and authorities in the USA and Europe. We aimed to critically evaluate and quantify the effects of ESAs on QoL in cancer patients.

METHODS

We included data from randomised controlled trials (RCTs) on the effects of ESAs on QoL in cancer patients. Randomised controlled trials were identified by searching electronic data bases and other sources up to January 2011. To reduce publication and outcome reporting biases, we included unreported results from clinical study reports. We conducted meta-analyses on fatigue- and anaemia-related symptoms measured with the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) and FACT-Anaemia (FACT-An) subscales (primary outcomes) or other validated instruments.

RESULTS

We identified 58 eligible RCTs. Clinical study reports were available for 27% (4 out of 15) of the investigator-initiated trials and 95% (41 out of 43) of the industry-initiated trials. We excluded 21 RTCs as we could not use their QoL data for meta-analyses, either because of incomplete reporting (17 RCTs) or because of premature closure of the trial (4 RCTs). We included 37 RCTs with 10581 patients; 21 RCTs were placebo controlled. Chemotherapy was given in 27 of the 37 RCTs. The median baseline haemoglobin (Hb) level was 10.1 g dl(-1); in 8 studies ESAs were stopped at Hb levels below 13 g dl(-1) and in 27 above 13 g dl(-1). For FACT-F, the mean difference (MD) was 2.41 (95% confidence interval (95% CI) 1.39-3.43; P<0.0001; 23 studies, n=6108) in all cancer patients and 2.81 (95% CI 1.73-3.90; P<0.0001; 19 RCTs, n=4697) in patients receiving chemotherapy, which was below the threshold (≥ 3) for a clinically important difference (CID). Erythropoiesis-stimulating agents had a positive effect on anaemia-related symptoms (MD 4.09; 95% CI 2.37-5.80; P=0.001; 14 studies, n=2765) in all cancer patients and 4.50 (95% CI 2.55-6.45; P<0.0001; 11 RCTs, n=2436) in patients receiving chemotherapy, which was above the threshold (≥ 4) for a CID. Of note, this effect persisted when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy. There was some evidence that the MDs for FACT-F were above the threshold for a CID in RCTs including cancer patients receiving chemotherapy with Hb levels below 12 g dl(-1) at baseline and in RCTs stopping ESAs at Hb levels above 13 g dl(-1). However, these findings for FACT-F were not confirmed when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy.

CONCLUSIONS

In cancer patients, particularly those receiving chemotherapy, we found that ESAs provide a small but clinically important improvement in anaemia-related symptoms (FACT-An). For fatigue-related symptoms (FACT-F), the overall effect did not reach the threshold for a CID.

Cancer and venous thromboembolic disease: from molecular mechanisms to clinical management

Venous thromboembolism (vte) represents a major challenge in the management of patients with cancer. The malignant phenotype is associated with derangements in the coagulation cascade that can manifest as thrombosis, hemorrhage, or disseminated intravascular coagulation. The risk of vte is increased by a factor of approximately 6 in patients with cancer compared with non-cancer patients, and cancer patients account for approximately 20% of all newly diagnosed cases of vte. Postmortem studies have demonstrated rates of vte in patients with cancer to be as high as 50%. Despite that prevalence, vte prophylaxis is underused in hospitalized patients with cancer. Studies have demonstrated that hospitalized patients with cancer are less likely than their non-cancer counterparts to receive vte prophylaxis. Consensus guidelines address the aforementioned issues and emerging concepts in the area, including the use of risk-assessment models, biomarkers to identify patients at highest risk of vte, and use of anticoagulants as anticancer therapy. Despite those guidelines, a gulf exists between current recommendations and clinical practice; greater efforts are thus required to ensure effective implementation of strategies to reduce the incidence of vte in patients with cancer.

Thrombosis and hemostatic abnormalities in hematological malignancies

There is a paucity of data that pertain to thrombosis in patients with hematological malignancies. Recent studies showed that patients with lymphoma, multiple myeloma, and acute leukemia have an increased thrombotic risk, particularly at the time of diagnosis and during chemotherapy. We searched the PubMed database for articles on thromboembolic complications in patients with hematological malignancies published between 1996 and 2013. The incidence of thrombotic events is variable, and is influenced by the type and the stage of hematological malignancy, the antitumor therapy, and the use of central venous devices. The pathogenesis of thromboembolic disease in hematological malignancies is multifactorial. Tumor cell-derived procoagulant, fibrinolytic, or proteolytic factors, and inflammatory cytokines affect clotting activation, and chemotherapy and immunomodulatory drugs increase the thrombotic risk in patients with lymphoma, acute leukemia, and multiple myeloma. Infections might also contribute to the pathogenesis of the thromboembolic complications: endotoxins from gram-negative bacteria induce the release of tissue factor, tumor necrosis factor and interleukin-1b, and gram-positive organisms can release bacterial mucopolysaccharides that directly activate factor XII. In the setting of plasma cell dyscrasias, hyperviscosity, decreased fibrinolysis, procoagulant autoantibody production, inflammatory cytokines, acquired activated protein C resistance, and the prothrombotic effects of antimyeloma agents might be the cause of thromboembolic complications. Anticoagulant therapy is very complicated because of high risk of hemorrhage. Therefore, an accurate estimate of a patient's thrombotic risk is essential to allow physicians to target thromboprophylaxis in high-risk patients.

Erythropoietin in cardiac disease: effective or harmful?

Discovered as the primary regulator of erythropoiesis, erythropoietin (EPO) is involved in a broad variety of processes that play a major role in cardiovascular diseases. In particular, the antiapoptotic and pro-angiogenic properties of EPO have prompted a growing interest in the use of EPO for the treatment of myocardial infarction and heart failure. In a variety of myocardial ischemic injury animal models, EPO administration has been shown to acutely reduce infarct size, thereby preserving ventricular function. In addition, cardiac long-term effects of EPO, such as prevention of ventricular remodeling and heart failure, have been described. In recent years, several trials have tested the effects of recombinant human erythropoietin (rhEPO) administration in patients with myocardial infarction and chronic heart failure, in the attempt to translate the cardioprotection found in experimental models to human patients. In view of the generally controversial findings, in this updated review we provide an overview of the results of the most recent trials that investigated the role of erythropoiesis-stimulating agents (ESAs), including rhEPO and its analogue darbepoetin, in the treatment of acute myocardial infarction and heart failure. The problems related to safety and tolerability of ESA therapy are also discussed. Our analysis of the available literature demonstrates that the results of clinical studies in patients with cardiac disease are not uniform and the conclusions are contradictory. Further larger prospective studies are required to test clinical efficacy and safety of EPO.

Erythropoietin action in stress response, tissue maintenance and metabolism

Erythropoietin (EPO) regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vascular endothelial response to increase nitric oxide production, which facilitates oxygen delivery to brain, heart and other non-hematopoietic tissues. This review discusses these and other reports of EPO action beyond red blood cell production, including EPO response affecting metabolism and obesity in animal models. Observations of EPO activity in cell and animal model systems, including mice with tissue specific deletion of EPO receptor (EpoR), suggest the potential for EPO response in metabolism and disease.

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.

Incidence and risk of hypertension with a novel multi-targeted kinase inhibitor axitinib in cancer patients: a systematic review and meta-analysis

AIMS

To investigate the overall incidence and risk of hypertension in cancer patients who receive axitinib and compare the differences in incidences between axitinib and the other four approved vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs).

METHODS

Several databases were searched, including Pubmed, Embase and Cochrane databases. Eligible studies were phase II and III prospective clinical trials of patients with cancer assigned axitinib at a starting dose of 5 mg orally twice daily with data on hypertension available. Overall incidence rates, relative risk (RR), and 95% confidence intervals (CI) were calculated employing fixed or random effects models depending on the heterogeneity of the included trials.

RESULTS

A total of 1908 patients from 10 clinical trials were included. The overall incidences of all grade and high grade hypertension in cancer patients were 40.1% (95% CI 30.9, 50.2%) and 13.1% (95% CI 6.7, 24%). The use of axitinib was associated with significantly increased risk of all grade (RR 3.00, 95% CI 1.29, 6.97, P = 0.011) and high grade hypertension (RR 1.71, 95% CI 1.21, 2.43, P = 0.003). The risk of axitinib associated all grade and high grade hypertension in renal cell carcinoma (RCC) was significantly higher than that in non-RCC. Additionally, the risk of hypertension with axitinib was substantially higher than other approved VEGFR-TKIs, while the risk of all grade hypertension with axitinib was similar to pazopanib (RR 1.05; 95% CI 0.95-, 1.17, P = 0.34).

CONCLUSIONS

While sharing a similar spectrum of target receptors with other VEGFR-TKIs, axitinib is associated with an unexpectedly high risk of developing hypertension. Close monitoring and appropriate management for hypertension are recommended during the treatment.

Temporal and Geographic Variations in the Receipt of Colony-Stimulating Factors and Erythropoiesis-Stimulating Agents in a Large Retrospective Cohort of Older Women With Breast Cancer From 2000 to 2009

The purpose of this study was to use the most recent national data for a large cohort of patients diagnosed with breast cancer to evaluate temporal trend of receiving hematopoietic growth factors from 2000 to 2009 and to examine significant factors associated with increasing trends and geographic variations. We identified 26,130 women aged 65-89 years who were diagnosed with breast cancer and received chemotherapy in 2000-2009 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Colony-stimulating factors (CSFs) were identified if there was a claim from the following procedure codes: filgrastim, pegfilgrastim, or sargramostim. Erythropoiesis-stimulating agents (ESAs) were identified if there was a claim from the following procedure codes: epoetin or darbepoetin. Overall, 51.7% of patients with breast cancer received CSFs, which increased from 21.7% in 2000 to 63.2% in 2009. The percentage of patients receiving pegfilgrastim increased from 2.7% in 2000 to 19.5% in 2003 and then continuously to 49.7% in 2009. The overall percentage of patients receiving ESAs was 39.3%, which increased from 26.4% in 2000 to 60.8% in 2006, and then decreased significantly from 40.7% in 2007 to 12.9% in 2009. The receipt of both CSFs and ESAs differed significantly across different geographic areas. The receipt of CSFs continued to increase from 2000 to 2009, and pegfilgrastim started to replace filgrastim since 2003. The receipt of ESAs increased until 2006 and then declined substantially due to the black box warning. There were substantial geographic variations in the use of these hematopoietic growth factors.

Treatment of anemia in inflammatory bowel disease--systematic review and meta-analysis

Background

Anemia is considered the most common systemic complication of inflammatory bowel disease (IBD). We aimed to provide all available evidence regarding the safety and efficacy of therapy existing today to correct anemia in IBD.

Methods

Systematic review and meta-analysis of randomized controlled trials that compared any treatment for anemia in patients with IBD. We searched electronic databases, conference proceedings and clinical trials registries. Two reviewers independently extracted data from included trials. The primary outcome was the effect of treatment for anemia in IBD on the hemoglobin (Hb) response, defined as rate of patients who achieved an increase of 2 g/dl in Hb concentration at the end of the follow-up. Secondary outcomes included disease severity scores, iron indices, Hb levels, inflammatory markers, adverse effects, and mortality. Dichotomous data were analysed by calculating the relative risk (RR) for each trial with the uncertainty in each result being expressed using 95% confidence intervals (CI). A fixed effect model was used, except in the event of significant heterogeneity between the trials (P<0.10, I²>40%), in which we used a random effects model.

Results

Nine trials fulfilled the inclusion criteria, to a total of 973 patients. We were able to perform meta-analysis for intravenous (IV) versus oral iron and for ESAs versus placebo. IV iron was associated with a higher rate of achieving Hb response in comparison to oral iron; RR 1.25 (95% CI 1.04–1.51, I² = 2%, 4 trials), CRP levels and disease activity indexes were not significantly affected by IV iron. IV iron was associated with a decrease in adverse events that required discontinuation of intervention and without an increase in serious adverse.

Discussion

Treatment for anemia in IBD should include IV iron and not oral iron replacement, due to improved Hb response, no added toxicity and no negative effect on disease activity.

Erythropoietin and the vascular wall: the controversy continues

BACKGROUND AND AIMS

Erythropoietin (EPO) stimulates erythropoiesis through its specific receptor (EPO-R). Preclinical work has assigned a role for the EPO/EPO-R system in the heart and blood vessels. The potential use of erythropoiesis-stimulating agents (ESAs) for nonhematopoietic indications is a focus of current research. This article considers proven actions of EPO in the cardiovascular system, with emphasis on the human responses.

DATA SYNTHESIS

By use of specific anti-EPO-R antibody no EPO-R protein was detected by Western blotting in normal non-erythroid tissues. Clinical trials failed to demonstrate clear beneficial effects of high-dosed ESAs in patients with coronary syndrome or myocardial infarct. While ESA therapy may lead to an elevation in arterial blood pressure in previously anemic patients, several studies have reported no effects on vessels/blood pressure with ESAs. EPO has been reported to stimulate angiogenesis. EPO-R mRNA is detectable in human vascular endothelium. However, in most vitro studies very high concentrations of EPO were applied and well-designed studies have failed to show direct effects of ESAs on endothelial cells. Whether EPO promotes the mobilization of myeloid progenitor cells into the blood stream still needs to be studied in more detail, as this effect may prove useful for augmenting the neovascularization of ischemic tissues. With respect to the administration of ESAs to tumor patients, a deeper insight into the role of EPO for tumor angiogenesis is desirable.

CONCLUSIONS

The enthusiastic reports of the nonhematopoietic cytoprotective potential of EPO and its derivatives in the cardiovascular system have not yet been confirmed in placebo-controlled clinical trials.

Thromboprophylaxis in ambulatory lung cancer treatment

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, are common problems experienced by patients with lung cancer that can impact treatment plans, prognoses, and survival. Patients with lung cancer are at greatest risk for development of VTE in the ambulatory care treatment setting. Literature does exist on VTE management for medical and surgical oncology inpatients, as well as clinical guidelines for inpatient prophylaxis; however, published evidence is lacking on outpatient risk and thromboprophylaxis in medical oncology outpatients, particularly patients with lung cancer. Because patients with lung cancer treated in the ambulatory setting have established risks for VTE, they may benefit from thromboprophylaxis. Clinical guidelines for outpatient thromboprophylaxis direct the clinical practice for thromboprophylaxis in lung cancer treatment. The purpose of the current article is to explore the VTE risks associated with ambulatory lung cancer treatment and to review the recommended guidelines for thromboprophylaxis to guide clinical decision making for patients with lung cancer.

Erythropoietin activates cell survival pathways in breast cancer stem-like cells to protect them from chemotherapy

Recombinant erythropoietin (EPO) analogs [erythropoiesis-stimulating agents (ESA)] are clinically used to treat anemia in patients with cancer receiving chemotherapy. After clinical trials reporting increased adverse events and/or reduced survival in ESA-treated patients, concerns have been raised about the potential role of ESAs in promoting tumor progression, possibly through tumor cell stimulation. However, evidence is lacking on the ability of EPO to directly affect cancer stem-like cells, which are thought to be responsible for tumor progression and relapse. We found that breast cancer stem-like cells (BCSC) isolated from patient tumors express the EPO receptor and respond to EPO treatment with increased proliferation and self-renewal. Importantly, EPO stimulation increased BCSC resistance to chemotherapeutic agents and activated cellular pathways responsible for survival and drug resistance. Specifically, the Akt and ERK pathways were activated in BCSC at early time points following EPO treatment, whereas Bcl-xL levels increased at later times. In vivo, EPO administration counteracted the effects of chemotherapeutic agents on BCSC-derived orthotopic tumor xenografts and promoted metastatic progression both in the presence and in the absence of chemotherapy treatment. Altogether, these results indicate that EPO acts directly on BCSC by activating specific survival pathways, resulting in BCSC protection from chemotherapy and enhanced tumor progression.

Cytoprotective effect of recombinant human erythropoietin produced in transgenic tobacco plants

Asialo-erythropoietin, a desialylated form of human erythropoietin (EPO) lacking hematopoietic activity, is receiving increased attention because of its broader protective effects in preclinical models of tissue injury. However, attempts to translate its protective effects into clinical practice is hampered by unavailability of suitable expression system and its costly and limit production from expensive mammalian cell-made EPO (rhuEPO(M)) by enzymatic desialylation. In the current study, we took advantage of a plant-based expression system lacking sialylating capacity but possessing an ability to synthesize complex N-glycans to produce cytoprotective recombinant human asialo-rhuEPO. Transgenic tobacco plants expressing asialo-rhuEPO were generated by stably co-expressing human EPO and β1,4-galactosyltransferase (GalT) genes under the control of double CaMV 35S and glyceraldehyde-3-phosphate gene (GapC) promoters, respectively. Plant-produced asialo-rhuEPO (asialo-rhuEPO(P)) was purified by immunoaffinity chromatography. Detailed N-glycan analysis using NSI-FTMS and MS/MS revealed that asialo-rhuEPO(P) bears paucimannosidic, high mannose-type and complex N-glycans. In vitro cytoprotection assays showed that the asialo-rhuEPO(P) (20 U/ml) provides 2-fold better cytoprotection (44%) to neuronal-like mouse neuroblastoma cells from staurosporine-induced cell death than rhuEPO(M) (21%). The cytoprotective effect of the asialo-rhuEPO(P) was found to be mediated by receptor-initiated phosphorylation of Janus kinase 2 (JAK2) and suppression of caspase 3 activation. Altogether, these findings demonstrate that plants are a suitable host for producing cytoprotective rhuEPO derivative. In addition, the general advantages of plant-based expression system can be exploited to address the cost and scalability issues related to its production.

Polypharmacy and the management of the older cancer patient

Aging is associated with polymorbidity and polypharmacy. In the absence of a consensual definition, polypharmacy has been defined according to the number of drugs that an individual takes or to the presence of the risk of at least one severe drug interaction. In older cancer patients, polypharmacy is at least as common as it is in individuals of the same age without cancer. The management of cancer itself may result in the addition of more medications to counteract the adverse effects of antineoplastic treatment. Polypharmacy may be necessary to control the multiple health conditions of the older person, but it may represent a risk factor for more complications from antineoplastic therapy, and it may affect the outcome of cancer treatment. Polypharmacy is also associated with increased cost. The criteria proposed for the management of polypharmacy include the assessment that all medical conditions are properly treated, the avoidance of drug interactions, and of drugs that may compromise the outcome of antineoplastic treatment and the choice of drugs with the lowest risk of complications in older individuals.

Overview and assessment of risk factors for pulmonary embolism

Pulmonary embolism is one of the most common undiagnosed conditions affecting hospitalized patients. There are a plethora of risk factors for venous thromboembolism and pulmonary emboli. These factors are grouped under the broad triad of hypercoagulability, stasis and injury to provide a framework for understanding. Important risk factors include inherited thrombophilia, age, malignancy and estrogens. These risk factors are reviewed in detail and several risk assessment models are reviewed. These risk assessment models help identify those at risk for disease and therefore candidates for thromboprophylaxis. Diagnosis can be difficult and is aided by clinical decision rules that incorporate clinical scores that define the likelihood of pulmonary embolism. These are important considerations, not only for diagnostic purposes, but also to minimize excessive use of imaging, which increases exposure to and risks associated with radiation. A healthy index of suspicion is often the key to diagnosis.

Modeling of treatment response to erythropoiesis-stimulating agents in older (age≥70years) and younger (age<70years) patients with cancer and anemia: findings from the Anemia Cancer Treatment study

INTRODUCTION

The Anemia Cancer Treatment study assessed hemoglobin (Hb) outcomes following treatment with erythropoiesis-stimulating agents (ESA) in anemic (Hb≤11g/dL) patients in Europe. We replicated the original analyses stratifying by age, namely patients aged ≥70 (n=637) versus those aged<70 (n=1555).

MATERIALS AND METHODS

A secondary analysis of Hb outcomes was assessed over 8-10weeks. Treatment response criteria included increases of Hb≥1g/dL, Hb≥1g/dL over 8weeks, and Hb≥2g/dL over the course of the study period.

RESULTS

Mean Hb increased from similar levels of 9.5g/dL [p=not significant (ns)] at visit one to 10.9g/dL (p=ns) at visit three (both p<0.001). Patients aged≥70 had higher mean Hb at visit two (10.6g/dL vs. 10.3g/dL, p<0.001). Cohorts did not differ in treatment response rates (all p=ns). Mean performance status differed between cohorts at each visit (all p≤0.011); both groups showed significant improvements (both p<0.001). Immediacy of response was a consistent determinant but was more pronounced among patients aged≥70. Less consistent determinants included performance status in the age≥70 group, as well as hematological malignancy and Hb at ESA start in the age<70 group. The proportion of variance in Hb outcomes attributable to treatment center ranged from 0.090 to 0.289 in the age≥70 cohort and 0.126 to 0.361 in the age<70 cohort.

CONCLUSIONS

Both groups achieved similar Hb levels with the age≥70 cohort showing a higher initial evolution rate and potentially a different Hb response trajectory. Patients age≥70 were more likely to benefit from ESAs if showing an early erythropoietic response and exhibiting no or little impairment in performance status. Differential attribution of variability in older vs. younger adults suggests that individualization of ESA therapy may facilitate Hb response in geriatric patients with cancer.

Impact of erythropoietin on intensive care unit patients

Anemia is common in intensive care unit (ICU) patients. Red blood cell (RBC) transfusions are mainstays of their treatment and can be life-saving. Allogeneic blood components inherently bear risks of infection and immune reactions. Although these risks are rare in developed countries, recombinant human erythropoietin (rhEpo) and other erythropoiesis-stimulating agents (ESAs) have been considered alternative anti-anemia treatment options. As summarized herein, however, most of the clinical studies suggest that ESAs are not usually advisable in ICU patients unless approved indications exist (e.g., renal disease). First, ESAs act in a delayed way, inducing an increase in reticulocytes only after a lag of 3-4 days. Second, many critically ill patients present with ESA resistance as inflammatory mediators impair erythropoietic cell proliferation and iron availability. Third, the ESA doses used for treatment of ICU patients are very high. Fourth, ESAs are not legally approved for general use in ICU patients. Solely in distinct cases, such as Jehovah's Witnesses who refuse allogeneic blood transfusions due to religious beliefs, ESAs may be considered an exceptional therapy.

Anemia, heart failure and evidence-based clinical management

Anemia is a prevalent comorbidity and marker of a poorer prognosis in patients with heart failure (HF). Its clinical relevance, as well as its pathophysiology and the clinical management of these patients are important subjects in the specialized literature. In the present review, we describe the current concepts on the pathophysiology of anemia in HF, its diagnostic criteria, and the recommendations for iron supplementation. Also, we make a critical analysis of the major studies showing evidences on the benefits of this supplementation. The four main components of anemia are addressed: chronic disease, dilutional, "renal" and malabsorption. In patients with HF, the diagnostic criteria are the same as those used in the general population: serum ferritin levels lower than 30 mcg/L in patients without kidney diseases and lower than 100 mcg/L or serum ferritin levels between 100-299 mcg/L with transferring saturation lower than 20% in patients with chronic kidney diseases. Finally, the therapeutic possibilities for anemia in this specific patient population are discussed.

Incidence and risk of hemorrhagic events with vascular endothelial growth factor receptor tyrosine-kinase inhibitors: an up-to-date meta-analysis of 27 randomized controlled trials

BACKGROUND

We aimed at determining the overall incidence and risk of hemorrhagic events associated with vascular endothelial growth factor receptor-tyrosine-kinase inhibitors (VEGFR-TKIs).

METHODS

We searched PubMed, EMBASE and Cochrane library databases for relevant prospective, randomized controlled trials (RCTs). Statistical analyses were conducted to calculate the summary incidence, relative risks (RRs) and 95% confidence intervals (CIs) by using either random-effects or fixed-effects models according to the heterogeneity of included studies.

RESULTS

The overall incidence of all-grade and high-grade hemorrhagic events was 9.1% (95% CI: 6.8-12.1%) and 1.3% (95% CI 0.8% to 2.1%), respectively. And the use of VEGFR-TKIs was associated with an increased risk of hemorrhagic events, with a relative risk (RR) of 1.67 (95% CI 1.19-2.33, P = 0.003), but not for high-grade hemorrhagic events (RR 1.23, 95% CI 0.86-1.77, P = 0.25). The risk of developing all-grade hemorrhagic events varied significantly with tumor types (P < 0.001) and different VEGFR-TKIs (P < 0.001). Additionally, the most common causes of all-grade hemorrhagic events were hemoptysis (48.6%) and epistaxis (20.7%), while hemoptysis (41.8%) and CNS hemorrhage (13.4%) was the most common cause of high-grade hemorrhagic events.

CONCLUSIONS

While the use of VEGFR-TKIs is associated with a significantly increased risk of developing hemorrhagic events in cancer patients, this is primarily for lower grade events.

Epidemiology of cancer-associated venous thrombosis

Cancer-associated venous thrombosis is a common condition, although the reported incidence varies widely between studies depending on patient population, start and duration of follow-up, and the method of detecting and reporting thrombotic events. Furthermore, as cancer is a heterogeneous disease, the risk of venous thrombosis depends on cancer types and stages, treatment measures, and patient-related factors. In general, cancer patients with venous thrombosis do not fare well and have an increased mortality compared with cancer patients without. This may be explained by the more aggressive type of malignancies associated with this condition. It is hypothesized that thromboprophylaxis in cancer patients might improve prognosis and quality of life by preventing thrombotic events. However, anticoagulant treatment leads to increased bleeding, particularly in this patient group, so in case of proven benefit of thromboprophylaxis, only patients with a high risk of venous thrombosis should be considered. This review describes the literature on incidence of and risk factors for cancer-associated venous thrombosis, with the aim to provide a basis for identification of high-risk patients and for further development and refinement of prediction models. Furthermore, knowledge on risk factors for cancer-related venous thrombosis may enhance the understanding of the pathophysiology of thrombosis in these patients.