Venous thromboembolism in multiple myeloma: Current perspectives in pathogenesis

Bleeding risk from anticoagulant thromboprophylaxis in patients with multiple myeloma: a MarketScan analysis

Background

Multiple myeloma (MM) is associated with high risk of venous thromboembolism (VTE). Anticoagulant prophylaxis is frequently recommended but underutilized partly due to the absence of studies assessing bleeding risk.

Objectives

To determine the rate of severe (hospitalized) bleeding from thromboprophylaxis in patients treated for MM and identify clinical risk factors for bleeding in this population.

Methods

Using the MarketScan database, we analyzed 6656 patients treated for MM between 2013 and 2021. Concomitant thromboprophylaxis was defined using prescription claims. Hospitalized bleeding was identified through the Cunningham algorithm. Bleeding rates were compared by thromboprophylaxis status, and Cox regression identified risk factors for bleeding.

Results

Anticoagulant thromboprophylaxis was used in 6.6% (436) patients treated for MM. Patients on thromboprophylaxis had a higher rate of immunomodulatory-based therapy (63.8% vs 46.7%; P < .01) and lower rate of antiplatelet use (2.1% vs 4.7%; P < .01). Bleeding occurred in 1.4% of them during median follow-up of 1.3 years. Rate of severe bleeding was not different between those on prophylaxis (7.8 per 1000 person-years) and those not on prophylaxis (10.1 per 1000 person-years). No association was identified between thromboprophylaxis and bleeding. Factors associated with increased bleeding included age (hazard ratio [HR], 1.38 per 10 years increase in age), comorbidity index (HR, 1.18 per SD increase), history of bleeding (HR, 1.54), hypertension (HR, 1.87), and renal disease (HR, 1.56).

Conclusion

Risk of serious bleeding from thromboprophylaxis in patients treated for MM was low, and concomitant anticoagulant therapy did not result in increased bleeding risk. Clinical risk factors for bleeding included age, comorbidity index, bleeding history, hypertension, and renal disease.

Diagnosis and management of smouldering myeloma: A British Society for Haematology Good Practice Paper

Multiple myeloma is a bone marrow-based plasma cell tumour that develops from asymptomatic pre-cursor conditions smouldering myeloma and monoclonal gammopathy of uncertain significance and all are characterised by the presence of a monoclonal protein in the blood. Diagnosis and distinction between these conditions is based on blood tests, the bone marrow biopsy and cross sectional imaging. There are various risk stratification models that group patients with smouldering myeloma into risk groups based on risk of progression to symptomatic disease. Management is mainly observational for patients with smouldering myeloma although clinical trials for high-risk disease may be available. Restaging is required if evidence for progression.

Assessing the risk of venous thromboembolism in patients with haematological cancers using three prediction models

PURPOSE

Assessment of individual VTE risk in cancer patients prior to chemotherapy is critical for determining necessity of interventions. Risk assessment models (RAM) are available but have not been validated for haematological malignancy. We aimed to assess the validity of the Vienna Cancer and Thrombosis Study (V-CATS) score in prediction of VTE in a variety of haematological malignancies.

METHODS

This is a prospective cohort study conducted on 81 newly diagnosed cancer patients undergoing chemotherapy. Demographic, clinical and cancer related data were collected, patients were followed up for 6 months, and VTE events were recorded. Khorana score (KS) was calculated. Plasma D-dimer and sP-selectin were measured, and then, V-CATS score was calculated. Receiver operator curve (ROC) was used to assess the sensitivity and specificity of RAMs. A modified V-CATS was generated and subsequently assessed by using new cut-off levels of d-dimer and sP-selectin based on ROC curve of the patients' results and compared the probability of VTE occurrence using all three RAMs.

RESULTS

Among the 81 patients included in this study, a total of 2.7% were diagnosed with advanced metastatic cancer. The most frequent cancer was non-Hodgkin lymphoma (39.5%), and 8 patients (9.8%) developed VTE events. The calculated probability of VTE occurrence using KS, V-CATS and modified V-CATS scores at cut-off levels ≥ 3 was 87.5%, 87.5% and 100%, respectively. The AUC in ROC curve of modified Vienna CATS score showed significant difference when compared to that of V-CATS and KS (P = 0.047 and 0.029, respectively).

CONCLUSION

The findings of our study highlight the value of three VTE risk assessment models in haematological malignancies. The modified V-CATS score demonstrated higher specificity compared to both V-CATS and KS, while all three scores exhibited similar sensitivity. We encourage the implementation of RAMs in haematological cancers for an appropriate use of thromboprophylaxis.

Patients with multiple myeloma and monoclonal gammopathy of undetermined significance have variably increased thrombin generation and different sensitivity to the anticoagulant effect of activated protein C

BACKGROUND

Patients with multiple myeloma (MM) are at high risk of thrombosis especially when receiving immunomodulatory therapy. Thrombotic risk in patients with monoclonal gammopathy of undetermined significance (MGUS) may also be increased. Although activated protein C (APC) resistance has been linked to an increased risk of thrombosis in MM, little is known about how APC influences thrombotic risk in MGUS. We compared thrombin generation (TG) in MM and MGUS patients to that of healthy controls (HCs) and investigated the exogenous effect of APC on TG in these groups.

METHODS

Hemostasis tests including factor VIII (FVIII) and von Willebrand factor (vWF) levels were measured in platelet-poor plasma in 14 untreated MM patients, 34 MGUS patients, and 30 age and sex-matched HCs. TG assay was performed with or without the addition of APC.

RESULTS

Peak thrombin and velocity index were significantly higher in MM and MGUS patients compared to HCs, while MM patients also had elevated endogenous thrombin potential (ETP). In MGUS cases, ETP and peak thrombin values significantly correlated with FVIII and vWF levels. In the presence of APC, peak thrombin and ETP were reduced in MGUS and control plasmas whereas lagtime and time to peak were significantly prolonged. In contrast, adding APC to MM plasma had no effect on any TG parameters.

CONCLUSIONS

Hypercoagulability was observed in MM and even in MGUS cases with very low monoclonal protein concentration. In MM patients, APC had no effect on TG, but it attenuated TG in MGUS patients.

Bleeding risk in patients with multiple myeloma treated for venous thromboembolism: a MarketScan analysis

Background

Multiple myeloma (MM) is associated with high risk of venous thromboembolism (VTE). Thromboprophylaxis is thoroughly studied in MM. Contrarily, studies assessing the risk of bleeding in people with MM on anticoagulation are lacking.

Objectives

To determine the rate of serious bleeding in patients with MM receiving anticoagulation for VTE and the clinical factors associated with bleeding risk.

Methods

Using the MarketScan commercial database, we identified 1298 people with MM treated with anticoagulation for incident VTE events between 2011 and 2019. Hospitalized bleeding was identified using the Cunningham algorithm. Rates of bleeding were calculated and Cox regression identified risk factors for bleeding.

Results

Bleeding occurred in 51 (3.9%) cases during median follow-up of 1.13 years. Rate of bleeding among patients with MM on anticoagulation was 24.0 per 1000 person-years. In adjusted regression, factors associated with increased bleeding included age (HR, 1.31 per 10-year increase; 95% CI, 1.03-1.65), Charlson comorbidity index (HR, 1.29 per SD increase; 95% CI, 1.02-1.58), use of antiplatelet agents (HR, 2.4; 95% CI, 1.03-5.68), diabetes (HR, 1.85; 95% CI, 1.06-3.26), and renal disease (HR, 1.80; 95% CI, 1.05-3.16). Cumulative incidence of bleeding was 4.7%, 3.2%, and 3.4% for warfarin, low molecular weight heparin, and direct oral anticoagulants, respectively.

Conclusion

In this real-world analysis, the rate of bleeding in people with MM on anticoagulation was comparable to those in other subsets of cancer-related VTE. Bleeding rate was lower with low molecular weight heparin and direct oral anticoagulants than warfarin. Higher comorbidity index, diabetes, antiplatelet agent use, and renal disease were risk factors for serious bleeding.

Practical guidance for new multiple myeloma treatment regimens: A nursing perspective

As is the case for solid tumors, treatment paradigms have shifted from non-specific chemotherapeutic agents towards novel targeted drugs in the treatment of patients with multiple myeloma (MM). Currently, multiple targeted therapies are available to treat patients augmenting the arsenal of modalities which also includes chemotherapy, immunotherapy, radiation therapy, hematopoietic stem cell transplantation (HSCST) and chimeric antigen T-cell therapy (CAR-T). These novel, targeted agents have dramatically increased optimism for patients, who may now be treated over many years with successive regimens. As fortunate as we are to have these new therapies available for our patients, this advantage is juxtaposed with the challenges involved with delivering them safely. While each class of agents has demonstrated efficacy, in terms of response rates and survival, they also exert class effects which pose risks for toxicity. In addition, newer generation agents within the classes often have slightly different toxicity profiles than did their predecessors. These factors must be addressed, and their risks mitigated by the multidisciplinary team. This review presents a summary of the evolution of drug development for MM. For each targeted agent, the efficacy data from pivotal trials and highlights of the risks that were demonstrated in trials, as well as during post-marketing surveillance, are presented. Specific risks associated with agents within the classes, that are not shared with all new class members, are described. A table presenting these potential risks, with recommended nursing actions to mitigate toxicity, is provided as a quick reference that nurses may use during the planning, and provision, of patient care.

Optimising cardiovascular care of patients with multiple myeloma

Multiple myeloma (MM) is the third most common haematological malignancy, with increasing prevalence over recent years. Advances in therapy have improved survival, changing the clinical course of MM into a chronic condition and meaning that management of comorbidities is fundamental to improve clinical outcomes. Cardiovascular (CV) events affect up to 7.5% of individuals with MM, due to a combination of patient, disease and treatment-related factors and adversely impact survival. MM typically affects older people, many with pre-existing CV risk factors or established CV disease, and the disease itself can cause renal impairment, anaemia and hyperviscosity, which exacerabate these further. Up to 15% of patients with MM develop systemic amyloidosis, with prognosis determined by the extent of cardiac involvement. Management of MM generally involves administration of multiple treatment lines over several years as disease progresses, with many drug classes associated with adverse CV effects including high rates of venous and arterial thrombosis alongside heart failure. Recommendations for holistic management of patients with MM now include routine baseline risk stratification including ECG and echocardiography and administration of thromboprophylaxis drugs for patients treated with immunomodulatory drugs. Close surveillance of high-risk patients with collaboration between haematology and cardiology is required, with prompt investigation in the event of CV symptoms, in order to identify and treat complications early. Decisions regarding discontinuation of cardiotoxic therapies should be made in a multidisciplinary setting, taking into account the severity of the complication, prognosis, expected benefits and the availability of effective alternatives.

Validation of the IMPEDE VTE score for prediction of venous thromboembolism in multiple myeloma: a retrospective cohort study

The IMPEDE VTE score has recently emerged as a novel risk prediction tool for venous thromboembolism (VTE) in multiple myeloma (MM). We retrospectively reviewed 839 patients with newly diagnosed MM between 2010 and 2015 at Cleveland Clinic and included 575 patients in final analysis to validate this score. The c-statistic of the IMPEDE VTE score to predict VTE within 6 months of treatment start was 0·68 (95% CI: 0·61-0·75). The 6-month cumulative incidence of VTE was 5·0% (95% CI: 2·1-7·9) in the low risk group, compared to 12·6% (95% CI: 8·9-16·4%) and 24·1% (95% CI: 12·2-36·1) in the intermediate and high risk groups (P < 0·001 for both). In addition, a higher proportion of patients in the VTE cohort had ECOG performance status of ≥2 as compared to the no VTE cohort (33% vs. 16%, P = 0·001). Other MM characteristics such as stage, immunoglobulin subtype, and cytogenetics were not predictors of VTE. In summary, we have validated the IMPEDE VTE score in our patient cohort and our findings suggest that it can be utilized as a VTE risk stratification tool in prospective studies looking into investigating VTE prophylaxis strategies in MM patients.

Prothrombotic abnormalities in patients with multiple myeloma and monoclonal gammopathy of undetermined significance

BACKGROUND

Multiple myeloma (MM) and its precursor condition, monoclonal gammopathy of undetermined significance (MGUS) have an increased risk of thrombotic events, especially during anti-myeloma treatment. Many different underlying causes for this hypercoagulability have been suggested, but current techniques to identify abnormalities in these patients are sparse and inefficient. The aim of this study was to assess the hypercoagulability in MGUS and MM patients through various coagulation analyses and identify changes in the MM patients throughout their treatment regimen.

MATERIALS AND METHODS

Platelet-free plasma from 38 MM patients, 19 MGUS patients and 34 healthy controls were tested for hypercoagulability using calibrated automated thrombogram, a procoagulant phospholipid assay, a microvesicle-associated (MV) tissue factor (TF) assay, and a cell-free deoxyribonucleic acid (cf-DNA) assay as a surrogate measurement for neutrophil extracellular traps (NETs).

RESULTS

MGUS and MM patients both had elevated thrombin generation and procoagulant phospholipid activity in comparison to the control subjects. MM, and partly MGUS, showed increased MV-TF activity, however, only MM had increased levels of the cf-DNA.

CONCLUSIONS

Here we demonstrated that hypercoagulability was present in patients with MGUS and MM through increased thrombin generation, possibly due to higher TF and procoagulant phospholipids (PPL) activity. This may be associated to MVs and, for MM patients, be attributed to procoagulant NETs activity; however, this remains to be determined.

Acute non-heparin-induced thrombocytopenia during hemodiafiltration in a patient with multiple myeloma

This report demonstrates that not only heparin-induced thrombocytopenia, but also hemodialysis conditions (platelet activation due to hemodiafiltration and heparin underdosing) may markedly reduce the platelet count and cause clotting in the hemodialysis circuit in patients in a hypercoagulable state. The clot prevention effects of bortezomib are therefore of great importance.

Plasma Levels of Vascular Endothelial Growth Factor and Selected Hemostatic Parameters in Association With Treatment Response in Multiple Myeloma

Multiple myeloma (MM) is a neoplastic plasma cell disorder characterized by the clonal proliferation of plasma cells in the bone marrow and presence of monoclonal protein in the blood or urine. Diverse hemostatic abnormalities have been reported in patients with myeloma which predispose the patient to bleeding and also thrombosis. The aim of this study was to measure the concentrations of serum levels of vascular endothelial growth factor, D-dimer, and von Willebrand factor in patients with newly diagnosed or relapsed multiple myeloma before treatment, during therapy, and after successful therapy. The working hypothesis was that all of these factors reflect the total body burden of tumor. Angiogenic and coagulation activity should therefore decrease after successful therapy. Our study indicates that selected prothrombotic abnormalities occur in patients with MM, which may contribute to the increased risk of venous thromboembolism observed in these patients. The levels of our 3 parameters were strongly elevated in patient with newly diagnosed MM and also in patients with clinical stage III based on International Staging System criteria. Furthermore, there was a correlation between prognostic disease stages in all study population. It would be appropriate to include angiogenic and coagulation parameters into prognostic parameters.

Efficacy and Safety of Danshen Compound Tablets in Preventing Thalidomide-Associated Thromboembolism in Patients with Multiple Myeloma: A Multicenter Retrospective Study

BACKGROUND Currently available antithrombotic prophylaxis is not perfectly reliable in elderly patients. The aim of this retrospective study was to evaluate the efficacy and safety of Compound Danshen Tablet (CDT) in preventing thromboembolism in multiple myeloma (MM) patients treated with thalidomide-based regimens. MATERIAL AND METHODS MM patients treated with thalidomide-based regimens were retrospectively reviewed between January 2008 and March 2015. Patients were categorized into 3 cohorts based on thromboembolic prophylaxis used: CDT, Warfarin Tablet, and no prophylaxis. Venous thromboembolism (VTE), other adverse effects (AEs), and the changes of D-dimer and fibrinogen levels were monitored. RESULTS Seven out of 313 MM patients (2.24%) developed venous thrombosis events (VTE) in this retrospective study, all clustering in the no prophylaxis cohort. Three patients of the Warfarin cohort (3.19%) experienced hemorrhage. Neither VTE events nor serious AEs were observed in the CDT cohort. Following Compound Danshen or Warfarin treatment for 3 months, the D-dimer and fibrinogen levels (in particular the D-dimer level) (all P<0.05), were obviously decreased relative to their respective baselines and the no prophylaxis cohort. In contrast, the 2 blotting parameters were significantly increased in the no prophylaxis cohort relative to the baseline level (All P<0.05), and were even higher in the patients experiencing VTE compared to the no VTE patients (P<0.0001 and P=0.016, respectively). CONCLUSIONS Our findings indicate CDT is an effective therapy for preventing VTE in MM patients treated with thalidomide-based regimens, and is well tolerated in long-term use.

[Risk of venous thromboembolism in cancer patients: Reality, actuality and perspectives]

Cancer is a leading cause of venous thromboembolism (VTE) and vice versa. Pulmonary embolism is the second cause of death in cancer patients. Tumor progression is associated with coagulation activation. The pathogenesis of thrombosis during cancer is particularly complex stemming from multiple connections of this disease with both systems of inflammation and hemostasis. The risk of VTE depends on cancer type and the stage of the disease, the anticancer treatments and the time since cancer diagnosis as well as on the presence of patient-related risk factors (i.e. age, obesity, previous history of VTE, underlying diseases…). The presence of other precipitating factors and the duration of the exposure to them are also key elements in the assessment of such a thrombotic risk. It is therefore important to identify all the VTE risk factors to identify patients at high vascular risk and to determine the period during which this risk is significantly increased. The integration of biomarkers of hypercoagulability in proposed risk assessment models for VTE will improve their capacity to identify patients eligible for pharmacological thromboprophylaxis. In this review, we report the current status of knowledge on the connection between cancer and hypercoagulability, the numerous risk factors for VTE must be identified in cancer patients and the best methodology to build a more accurate assessment of this vascular risk in such a complex medical context.

Induction therapy alters plasma fibrin clot properties in multiple myeloma patients: association with thromboembolic complications

Induction therapy in patients with multiple myeloma increases the risk of thromboembolism. We have recently shown that multiple myeloma patients tend to form denser fibrin clots displaying poor lysability. We investigated the effect of induction therapy on fibrin clot properties in multiple myeloma patients. Ex-vivo plasma fibrin clot permeability, turbidity, susceptibility to lysis, thrombin generation, factor VIII and fibrinolytic proteins were compared in 48 multiple myeloma patients prior to and following 3 months of induction therapy, mainly with cyclophosphamide-thalidomide-dexamethasone regimen. Patients on thromboprophylaxis with aspirin or heparins were eligible. A 3-month induction therapy resulted in improved clot properties, that is higher clot permeability, compaction, shorter lag phase and higher final turbidity, along with shorter clot lysis time and higher rate of D-dimer release from fibrin clots than the baseline values. The therapy also resulted in lower thrombin generation, antiplasmin and thrombin-activatable fibrinolysis inhibitor (TAFI), but elevated factor VIII. Progressive disease was associated with lower posttreatment clot permeability and lysability. Despite thromboprophylaxis, two patients developed ischemic stroke and 10 had venous thromboembolism. They were characterized by pretreatment lower clot permeability, prolonged clot lysis time, longer lag phase, higher peak thrombin generation, TAFI and plasminogen activator inhibitor -1. Formation of denser plasma fibrin clots with reduced lysability and increased thrombin generation at baseline could predispose to thrombotic complications during induction treatment in multiple myeloma patients. We observed improved fibrin clot properties and thrombin generation in multiple myeloma patients except those with progressive disease.

[Multiple myeloma and venous thrombosis. Which thromboprophylaxis should be given?]

Multiple myeloma is a malignant plasma cells dyscrasia that mainly affects patients older than 65 years. These patients are at a higher risk for venous thromboembolism (VTE) because of cancer status, intrinsic risk factors, and exposure to prothrombotic therapies. The risk for VTE appears higher during the first months of myeloma treatment and decreases over time. Exposure to immunomodulatory drugs (IMIDs) such as thalidomide or lenalidomide in association with high doses of dexamethasone or anthracyclin-based chemotherapy is associated with a four-fold increased risk for VTE. Low-dose aspirin, preventive-dose of low molecular weight heparin (LMWH) or vitamin K antagonists were tested for primary prevention of VTE in myeloma patients receiving chemotherapy. The International Myeloma Working Group (IMWG) suggests stratifying VTE risk to decide which patients should receive VTE prevention. Then, the IMWG suggests giving low-dose aspirin to low VTE risk patients and LMWH or vitamin K antagonists to patients at high risk for VTE. For daily practice, it seems reasonable to start preventive doses of LMWH for 3 to 6 months in ambulatory myeloma patients receiving combined therapy with IMID and in all myeloma patients admitted to hospital.

Pulmonary Manifestations of Hematological Malignancies: Focus on Pulmonary Chronic Graft-Versus Host Disease

Advances in the management of patients in terms of the diagnosis and treatment of hematologic malignancies and treatment-related complications, especially infectious complications, have increased survival time. However, more than half of the patients treated for hematologic malignancies will develop a pulmonary complication during their follow-up, infectious pneumonia remaining the most common diagnosis that should be considered first in regard to its potential severity. Otherwise, new complications that may involve different organs, including the lungs, have been increasingly reported. Currently, over a quarter of lung infiltrates occurring in the context of hematological diseases are due to noninfectious causes. Thus, lung physicians may be increasingly confronted with these lung disorders. Various noninfectious pulmonary complications have been described in the different hematological malignancies; however, these complications are most often studied in the context of allogeneic hematopoietic stem cell transplantation (HSCT). In this chapter, we will briefly review the lung diseases associated with various hematological malignancies before focusing on noninfectious pulmonary complications following allogeneic HSCT.

Altered plasma fibrin clot properties and fibrinolysis in patients with multiple myeloma

BACKGROUND

Multiple myeloma (MM) is associated with increased risk of venous and arterial thromboembolism. Formation of denser and poorly lysable fibrin clots is observed in patients with arterial and venous thromboembolism. We investigated fibrin clot properties and their determinants in MM patients.

MATERIALS AND METHODS

Ex vivo plasma fibrin clot permeability, turbidity and susceptibility to lysis were evaluated in 106 MM patients at the time of diagnosis vs. 100 age- and sex-matched controls. MM patients had lower clot permeability (Ks ), compaction, indicating denser fibrin clots, impaired fibrin polymerization with longer lag phase and lower final turbidity (D-Dmax ), combined with hypofibrinolysis reflected by longer lysis time and slower rate of D-dimer release from fibrin clots (D-Drate ) compared with controls (all P < 0·001).

RESULTS

Patients with IgG MM had lower Ks compared with IgA MM [5·9 (5·1-6·4) vs. 6·3 (5·9-7·2) 10(-9)  cm(2) ; P = 0·007] and longer lysis time compared with light-chain-disease patients [11·4 (10·9-12·3) vs. 10·7 (9·8-11·9) min; P = 0·022]. Of the fibrin variables, only Ks was significantly lower in patients with International Staging System (ISS) grade III than in those with ISS grade I and II [5·9 (4·9-6·6) vs. 6·2 (5·7-6·8) 10(-9)  cm(2) ; P = 0·015]. Multivariate analysis adjusted for age and fibrinogen showed that in MM patients elevated peak thrombin levels determine Ks and D-Dmax , while thrombin-activatable fibrinolysis inhibitor (TAFI) activity predicts Ks , t50% , D-Drate and lag phase.

CONCLUSIONS

Our study demonstrates prothrombotic fibrin clot phenotype in patients with MM, with a significant impact of increased thrombin formation and TAFI activity.

Clinical and genetic factors associated with venous thromboembolism in myeloma patients treated with lenalidomide-based regimens

Lenalidomide has significant antimyeloma activity but it is associated with a significant risk of venous thromboembolism (VTE). In this study, we assessed clinical and genetic risk factors that may predispose for VTE in myeloma patients who were treated with lenalidomide-based regimens. We analyzed common clinical and selected genetic factors in 200 consecutive, unselected myeloma patients who were treated with lenalidomide-based regimens in a single institution. Twelve patients (6%) developed a VTE (nine deep venous thrombosis and three pulmonary embolism). All VTEs occurred in patients who were receiving aspirin prophylaxis; no patient who received LMWH or acenocoumarol had a VTE. The frequency of VTEs was 9.4% in previously untreated and 4.5% in previously treated patients. VTEs were more frequent in patients >65 years (8.1% vs. 1.6%) especially among patients receiving aspirin as prophylaxis (10.4% vs. 1.8% for patients ≤65 years). In patients who received prophylaxis with low dose aspirin a single-nucleotide polymorphism in NFκB1 (rs3774968) gene was associated with increased risk of VTE (OR 3.76, 95%CI 1-16, P = 0.051). None of the patients who developed VTEs had common genetic variations that are associated with increased risk of VTEs in the general population, such as FVLeiden and FIIG20210A. Our data indicated that LMWH or vitamin K antagonists (with a target INR 2-3) effectively reduce the risk of VTEs. In patients who received prophylaxis with aspirin genetic variants of genes that are involved directly or indirectly in inflammatory response may be associated with increased risk of VTE.

Thrombosis in hematologic malignancies: risks and consequences

SUMMARY Thrombotic complications in hematologic malignancies have been found to be high among the various forms of cancer. Thrombosis not only increases the morbidity, but also has an adverse impact on survival. The pathogenesis among the different forms of hematologic malignancies is reviewed in this article. The thrombogenicity of the individual malignant cells, the tumor burden, treatment modalities and presence of comorbidities are among the major risk factors. These factors vary with the acute leukemias, lymphomas, multiple myeloma and myeloproliferative neoplasms. The thrombogenetic factors in the more common hematologic malignancies are discussed. Results of recent randomized controlled clinical trials are beginning to provide data for meaningful therapeutic guidelines on thromboprophylaxis. They also enable the clinician to assess the risk factors in each individual patient. More clinical trials are needed to provide better risk stratification and to devise risk-adapted treatment regimens.

Bortezomib alleviates experimental pulmonary arterial hypertension

Vascular remodeling and endothelial dysfunction are important pathogenic features of pulmonary arterial hypertension (PAH). There is a growing body of evidence that proteasome inhibitors may be beneficial in vascular diseases by inhibiting proliferation of vascular smooth muscle cells (VSMCs) and ameliorating endothelial dysfunction. Here, we evaluated whether bortezomib (BTZ) could alleviate hypoxia- and monocrotaline (MCT)-induced PAH. BTZ (at doses from 1 to 100 μg/kg, or a dose of 100 μg/kg) was administered to mice every other day for the last 2 weeks of a 5-week hypoxia (10% O(2)) period, or to rats once daily from Day 22 to Day 34 after MCT challenge, respectively. BTZ treatment substantially suppressed elevation of right ventricular (RV) systolic pressure, RV hypertrophy, and pulmonary vascular remodeling in hypoxia-exposed mice. Similarly, BTZ treatment inhibited RV hypertrophy and vascular remodeling in MCT-injected rats. Strikingly, BTZ rescued 70% of MCT-injected rats up to Day 60, along with a considerable reduction in RV systolic pressure and suppression of vascular remodeling, whereas, among MCT-injected rats not administered BTZ, there were no survivors by Day 41. BTZ significantly suppressed proliferation of pulmonary VSMCs in vivo and in vitro. Furthermore, BTZ increased not only endothelial nitric oxide (NO) synthase (eNOS), phosphorylated eNOS, and NO production in vitro, but also eNOS and p-eNOS in hypoxia-exposed mice and MCT-injected rats, respectively. In contrast to the beneficial effects, BTZ increased active caspase-3 in cardiac ventricles of MCT-injected rats. Taken together, with caution for cardiotoxicity, BTZ could be a potential therapeutic strategy in PAH, possibly acting by inhibition of VSMC proliferation and amelioration of endothelial dysfunction.

Evidence-based case report: multiple thrombotic episodes associated with lenalidomide and dexamethasone therapy for multiple myeloma

Lenalidomide in combination with dexamethasone is a treatment for patients with relapsed or refractory myeloma. Although this combination demonstrates a high level of efficacy, it further exacerbates the hypercoaguable state that exists within myeloma. Thromboprophylactic regimen require careful selection and if warfarin is chosen, assiduous monitoring is required to ensure it will be clinically effective. We report the case of one patient who experienced multiple thrombotic events despite anticoagulant or antiplatelet thromboprophylaxis and review the contributing factors.

Lower dose dexamethasone/thalidomide and zoledronic acid every 3 weeks in previously untreated multiple myeloma

BACKGROUND

Physicians in Asia have anecdotally reported that Asian patients with multiple myeloma (MM) are frequently intolerant of conventional doses of dexamethasone (Dex) and/or thalidomide (Thal). Since zoledronic acid (Zol) has an anti-MM effect in preclinical studies, we investigated whether the approved 3-times-weekly Zol combined with lower dose Dex/Thal could be an effective and better tolerated regimen in Asian patients.

PATIENTS AND METHODS

In this first Asian cooperative multicenter phase II study, previously untreated patients with MM (N = 44) received up to 6 cycles of 3-times-weekly low-dose Dex/Thal and 4 mg Zol (the dtZ regimen). Response was graded using Bladé criteria.

RESULTS

The average doses of Dex and Thal administered were 185.2 mg/month; and 87.5 mg/day, respectively. Thirty-nine (88.6%) patients demonstrated at least a partial response (PR), including 18.2% very good partial response (VGPR), 15.9% near complete response (nCR) and 18.2% complete response (CR). Achievement of CR/nCR was related to significant (P < .05), rapid, and sustained inhibition of osteoclasts (OCs) and OC precursors (pOCs) by Zol. Sepsis was the most frequently reported serious toxicity, contributing to 3 of 4 deaths. Importantly, there was no peripheral neuropathy, osteonecrosis of the jaw, or nephrotoxicity.

CONCLUSION

We conclude that the dtZ regimen is an effective and well-tolerated regimen for Asian patients with newly diagnosed MM. The high rate of VGPR/nCR/CR suggests that Zol could have a clinically relevant anti-MM effect. Since infections are the most frequent adverse event, it is probably wise to further lower the dose of Dex in future studies.

Inflammation, TNFα and endothelial dysfunction link lenalidomide to venous thrombosis in chronic lymphocytic leukemia

Patients receiving lenalidomide are at an increased risk for deep venous thrombosis (DVT). Here, we prospectively investigated the DVT risk in patients with relapsed chronic lymphocytic leukemia (CLL) treated with lenalidomide (n = 32). Five patients developed six incidents of DVT over 1 year for an annual incidence of 16%. Three of these were considered drug-related. Median time to DVT was 105 days (range 56-259 days). No pulmonary embolism was detected. Hypercoagulability screen before study entry was negative in all patients who subsequently developed DVTs. Compared to normal volunteers CLL patients had increased baseline levels of D-dimer, thrombin-antithrombin, soluble vascular endothelial adhesion molecule 1 (sVCAM-1), and thrombomodulin (p < 0.001). After 1 week on lenalidomide D-dimer, thrombomodulin, sVCAM-1, factor VIII, TNFα, and C-reactive protein were significantly increased while protein C was decreased (p < 0.001). In patients with lenalidomide-related DVTs, TNFα, and sVCAM-1 were more strongly upregulated than in all other patients (p < 0.05) and TNFα and sVCAM-1 levels were significantly correlated (r = 0.65, p < 0.001). These data link lenalidomide associated DVTs with TNFα upregulation and endothelial cell dysfunction and suggest that aspirin may have a role for DVT prophylaxis in these patients.

Venous thromboembolism prophylaxis after hospital discharge: transition to preventive care

Deep vein thrombosis and pulmonary embolism, the common clinical manifestations of venous thromboembolism (VTE), are among the most preventable complications of hospitalized patients. However, survey data repeatedly show poor rates of compliance with guideline-based preventive strategies. This has led the Centers for Medicare and Medicaid Services to deny reimbursement for hospital readmission for thromboembolic complications in patients undergoing total hip or knee arthroplasty. Multiple strategies and national initiatives have been developed to improve rates of VTE prophylaxis during hospitalization; however, most VTE occurs in the outpatient setting. Epidemiologic data suggest that recent surgery or hospitalization is a strong risk factor for the development of VTE and that this risk may persist for up to 6 months. These observations call into question whether VTE prophylaxis should be administered only during hospitalization or if this preventive strategy should be continued after hospital discharge. Many of the randomized trials showing efficacy of VTE prophylaxis have used longer durations of prophylaxis than are typical for current length of hospital stay, highlighting the issue of how long the duration of prophylaxis should be. Several patient groups have undergone formal testing to evaluate the risks and benefits of extended-duration VTE prophylaxis, but this issue is less clear for other categories of patients. Although there is clear consensus that most hospitalized patients should receive VTE prophylaxis, there is uncertainty about whether to continue VTE prophylaxis in the immediate post-hospital period or for an extended duration. The transition from inpatient to outpatient care is a key event in the coordination of continuity of care, but VTE-specific care transition guidance is limited. In this article, we review the evidence for both standard- and extended-duration VTE prophylaxis and discuss the difficulties in effectively maintaining VTE prophylaxis during the transition from inpatient to outpatient care.

Low venous thromboembolic risk with bortezomib in multiple myeloma and potential protective effect with thalidomide/lenalidomide-based therapy: review of data from phase 3 trials and studies of novel combination regimens

Patients with multiple myeloma (MM) are at elevated risk of venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE). VTE risk in MM is increased by various patient- and disease-related factors. The type of anti-MM therapy represents a key factor, with a substantially elevated VTE risk in patients treated with the immunomodulatory drugs (IMiDs) thalidomide or lenalidomide in combination with dexamethasone and/or chemotherapy; VTE risk with lenalidomide-dexamethasone is further increased with concomitant erythropoietin. By contrast, treatment with the proteasome inhibitor bortezomib, alone or in combination, does not increase VTE risk; rates of DVT/PE do not appear affected by the use of erythropoiesis-stimulating agents. Bortezomib has shown antihemostatic effects in patients with relapsed or refractory MM, which supports that it exerts antithrombotic actions and thus potentially provides a protective effect in combination with regimens with an elevated VTE risk. Herein, we review data from phase 3 trials of bortezomib- and/or IMiD-based therapy in frontline MM, together with other studies of novel combination regimens. Despite the confounding effect of variable VTE prophylaxis, bortezomib-based regimens were typically associated with DVT/PE rates of ≤5%, similar to those seen with melphalan-prednisone and dexamethasone, whereas IMiD-based bortezomib-free regimens were generally associated with higher rates. Direct comparisons of regimens of thrombogenic potential with or without bortezomib demonstrated lower VTE risk with bortezomib. Between-study comparisons of VTE risk support these findings. Taken together, these data confirm the low VTE risk associated with bortezomib and support a potential protective effect of bortezomib in combination with IMiD-based regimens associated with elevated VTE risk.

Arterial and venous thrombosis in cancer patients

The most frequent ultimate cause of death is myocardial arrest. In many cases this is due to myocardial hypoxia, generally arising from failure of the coronary macro- and microcirculation to deliver enough oxygenated red cells to the cardiomyocytes. The principle reason for this is occlusive thrombosis, either by isolated circulating thrombi, or by rupture of upstream plaque. However, an additionally serious pathology causing potentially fatal stress to the heart is extra-cardiac disease, such as pulmonary hypertension. A primary cause of the latter is pulmonary embolus, considered to be a venous thromboembolism. Whilst the thrombotic scenario has for decades been the dominating paradigm in cardiovascular disease, these issues have, until recently, been infrequently considered in cancer. However, there is now a developing view that cancer is also a thrombotic disease, and notably a disease predominantly of the venous circulation, manifesting as deep vein thrombosis and pulmonary embolism. Indeed, for many, a venous thromboembolism is one of the first symptoms of a developing cancer. Furthermore, many of the standard chemotherapies in cancer are prothrombotic. Accordingly, thromboprophylaxis in cancer with heparins or oral anticoagulation (such as Warfarin), especially in high risk groups (such as those who are immobile and on high dose chemotherapy), may be an important therapy. The objective of this communication is to summarise current views on the epidemiology and pathophysiology of arterial and venous thrombosis in cancer.

Coagulation profiles and thromboembolic events of bortezomib plus thalidomide and dexamethasone therapy in newly diagnosed multiple myeloma

Patients with multiple myeloma (MM) are at relatively high risk of developing thromboembolic event (TEE), especially during treatment with immunomodulatory agents. We characterized coagulation profiles and evaluate the incidence of TEE associated with the combination therapy of bortezomib-thalidomide-dexamethasone (VTD) in Chinese patients with newly diagnosed MM. The results indicated that the platelet count and platelet aggregation induced by the agonists were decreased after a short exposure to bortezomib in vivo. The incidence of TEE was low in VTD therapy for an overall rate of 3%. We do not recommend routine thromboprophylaxis for VTD therapy in Chinese patients with MM.