Arterial thrombosis in four patients treated with thalidomide

Thrombospondin-1 is an endogenous substrate of cereblon responsible for immunomodulatory drug-induced thromboembolism

ABSTRACT

Immunomodulatory drugs (IMiDs) are key drugs for treating multiple myeloma and myelodysplastic syndrome with chromosome 5q deletion. IMiDs exert their pleiotropic effects through the interaction between cell-specific substrates and cereblon, a substrate receptor of the E3 ubiquitin ligase complex. Thus, identification of cell-specific substrates is important for understanding the effects of IMiDs. IMiDs increase the risk of thromboembolism, which sometimes results in fatal clinical outcomes. In this study, we sought to clarify the molecular mechanisms underlying IMiDs-induced thrombosis. We investigated cereblon substrates in human megakaryocytes using liquid chromatography-mass spectrometry and found that thrombospondin-1 (THBS-1), which is an inhibitor of a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13, functions as an endogenous substrate in human megakaryocytes. IMiDs inhibited the proteasomal degradation of THBS-1 by impairing the recruitment of cereblon to THBS-1, leading to aberrant accumulation of THBS-1. We observed a significant increase in THBS-1 in peripheral blood mononuclear cells as well as larger von Willebrand factor multimers in the plasma of patients with myeloma, who were treated with IMiDs. These results collectively suggest that THBS-1 represents an endogenous substrate of cereblon. This pairing is disrupted by IMiDs, and the aberrant accumulation of THBS-1 plays an important role in the pathogenesis of IMiDs-induced thromboembolism.

Comparison of Anticancer Drug Toxicities: Paradigm Shift in Adverse Effect Profile

The inception of cancer treatment with chemotherapeutics began in the 1940s with nitrogen mustards that were initially employed as weapons in World War II. Since then, treatment options for different malignancies have evolved over the period of last seventy years. Until the late 1990s, all the chemotherapeutic agents were small molecule chemicals with a highly nonspecific and severe toxicity spectrum. With the landmark approval of rituximab in 1997, a new horizon has opened up for numerous therapeutic antibodies in solid and hematological cancers. Although this transition to large molecules improved the survival and quality of life of cancer patients, this has also coincided with the change in adverse effect patterns. Typically, the anticancer agents are fraught with multifarious adverse effects that negatively impact different organs of cancer patients, which ultimately aggravate their sufferings. In contrast to the small molecules, anticancer antibodies are more targeted toward cancer signaling pathways and exhibit fewer side effects than traditional small molecule chemotherapy treatments. Nevertheless, the interference with the immune system triggers serious inflammation- and infection-related adverse effects. The differences in drug disposition and interaction with human basal pathways contribute to this paradigm shift in adverse effect profile. It is critical that healthcare team members gain a thorough insight of the adverse effect differences between the agents discovered during the last twenty-five years and before. In this review, we summarized the general mechanisms and adverse effects of small and large molecule anticancer drugs that would further our understanding on the toxicity patterns of chemotherapeutic regimens.

Isolated duodenal ischemia of unknown etiology: a case report

Background

Acute abdomen is among the most common presentations observed in clinical practice. The present study describes a patient with isolated duodenal ischemia as an extremely rare etiology of acute abdomen.

Case presentation

A 79-year-old male with acute abdominal pain, nausea, and vomiting presented to the emergency department of our hospital. He was diagnosed with myelodysplastic syndrome 7 years ago, for which he took thalidomide and erythropoietin as the main medications. The prominent findings of the physical examination were hypotension, tachycardia, fever, mild hypoxemia, and epigastric and right upper quadrant tenderness of the abdomen. Except for mildly increased creatinine and lipase, other laboratory findings were in concordance with myelodysplastic syndrome. Due to the patient’s oliguria, the computed tomography (CT) scan was performed without contrast, which, together with the ultrasonography, raised the clinical impression of acute pancreatitis. The patient’s hypotension was refractive to supportive treatment, resulting in progressive deterioration of the clinical condition. A later contrast-enhanced CT scan suggested microvascular ischemia of the duodenum. An emergent Whipple’s procedure was planned initially, which was later switched to a damage control surgery due to the patient’s cardiac arrest during the surgery. Despite all the supportive therapy provided at the intensive care unit, the patient expired of a cardiac arrest which occurred two hours after the termination of the surgery.

Conclusions

The high rate of mortality in duodenal necrosis necessitates emergent diagnosis and proper management. When other common etiologies are ruled out, clinicians should consider duodenal pathology as a potential cause of acute abdomen.

Thrombotic and bleeding risk of angiogenesis inhibitors in patients with and without malignancy

Over the past two decades, therapies targeting angiogenesis have developed into a major class of cancer therapeutics. The vascular endothelial growth factor (VEGF) family of signaling proteins, a group of potent angiogenic growth factors, and their receptors represent the main targets of this therapeutic class. To date, 16 antiangiogenic agents have been approved in the United States for the treatment of cancer and several more are in development. An important consideration with antiangiogenic therapy is toxicity, in particular thrombotic and bleeding risks. These complications have emerged as a major clinical concern that may affect the use of these agents in patients both with and without cancer who may already have an elevated risk of thrombosis and bleeding. Although these agents are frequently considered together as a class when contemplating their bleeding and thrombotic risks, in fact the risks for venous thromboembolism, arterial thrombosis, and bleeding vary significantly between different classes of antiangiogenic agents and even among different agents within a class. In this narrative review, we describe the literature investigating the venous and arterial thrombotic and bleeding risks associated with the currently available antiangiogenic drugs. In addition, we discuss these specific complications in the context of both cancer therapy as well as the management of nonmalignant disorders now managed with antiangiogenic agents, including hereditary hemorrhagic telangiectasia and neovascular age-related macular degeneration.

Cancer therapies based on targeted protein degradation - lessons learned with lenalidomide

For decades, anticancer targeted therapies have been designed to inhibit kinases or other enzyme classes and have profoundly benefited many patients. However, novel approaches are required to target transcription factors, scaffolding proteins and other proteins central to cancer biology that typically lack catalytic activity and have remained mostly recalcitrant to drug development. The selective degradation of target proteins is an attractive approach to expand the druggable proteome, and the selective oestrogen receptor degrader fulvestrant served as an early example of this concept. Following a long and tragic history in the clinic, the immunomodulatory imide drug (IMiD) thalidomide was discovered to exert its therapeutic activity via a novel and unexpected mechanism of action: targeting proteins to an E3 ubiquitin ligase for subsequent proteasomal degradation. This discovery has paralleled and directly catalysed myriad breakthroughs in drug development, leading to the rapid maturation of generalizable chemical platforms for the targeted degradation of previously undruggable proteins. Decades of clinical experience have established front-line roles for thalidomide analogues, including lenalidomide and pomalidomide, in the treatment of haematological malignancies. With a new generation of 'degrader' drugs currently in development, this experience provides crucial insights into class-wide features of degraders, including a unique pharmacology, mechanisms of resistance and emerging therapeutic opportunities. Herein, we review these past experiences and discuss their application in the clinical development of novel degrader therapies.

An absence of platelet activation following thalidomide treatment in vitro or in vivo

Increased risk of thromboembolism and platelet hyperreactivity has been reported in patients receiving thalidomide therapy. Whether thalidomide induces platelet activation directly or through other factors remains unclear. The aim of this study was to evaluate the effect of thalidomide on platelet activation under resting conditions in vitro and in vivo. Isolated human or mouse platelets were treated with different concentrations of thalidomide (10, 50 and 100 μg/ml) for 60 min at 37°C followed by analysis of platelet surface expression of platelet receptors GPIbα, GPVI, α_IIbβ₃ and P-selectin, and PAC-1 or fibrinogen binding, by flow cytometry and collagen- or ADP-induced platelet aggregation. In addition, thalidomide (200 mg/kg) was intraperitoneally injected into mice for analysis of the effect of thalidomide on platelet activation in vivo. No increased expression of P-selectin, PAC-1 or fibrinogen binding was observed in either human and mouse platelets after thalidomide treatment in vitro for 60 min at 37°C. Thalidomide treatment also did not affect expression of GPIbα, GPVI or α_IIbβ₃, nor did it affect collagen- or ADP-induced platelet aggregation at threshold concentrations. However, while mice injected with thalidomide displayed no increased surface expression of platelet P-selectin or α_IIbβ₃, there was a significantly shortened tail bleeding time, thrombin time, prothrombin time together with higher levels of Factor IX and fibrinogen. In conclusion, thalidomide at therapeutic doses does not directly induce platelet activation under resting conditions in vitro or in vivo, but results in increased procoagulant activity, which could explain the thalidomide-dependent prothrombotic tendency in patients.

Real-life practices for preventing venous thromboembolism in multiple myeloma patients: a cohort study from the French health insurance database

PURPOSE

The risk of venous thromboembolic event (VTE) in multiple myeloma is particularly increased. Current guidelines recommend systematic VTE prophylaxis with vitamin K antagonists (VKA) or low weight molecular heparin (LWMH) or unfractionated heparin (UFH) in high-risk patients, based on treatment received [e.g. use of IMiDs (thalidomide, lenalidomide and pomalidomide), alkylating agents or erythropoietin] and individual risk factors (e.g. history of VTE). The aim of this study was to describe strategy of VTE prophylaxis and prescribing of other antithrombotic agents during the first 6 months of multiple myeloma therapy, with stratification on IMiD-based regimens and drug and disease-related risk factors.

METHODS

A retrospective cohort study of French beneficiaries from the health insurance database (SNIIRAM, Système National d'Information Inter-Régime de l'Assurance Maladie) was designed in the Midi-Pyrénées area (South West France). Patients starting a treatment for multiple myeloma in the period 2011-2014 were identified through hospital and chronic disease diagnoses.

RESULTS

Among the 236 incident multiple myeloma patients, 56% male (n = 133), 67% >65 years (n = 159) and 47% (n = 110) patients received an IMiD-based regimen. In these patients, 63% (n = 69) were identified as high-risk patients with indication for low molecular weight heparin or equivalent, and 37% (n = 41) were identified as low-risk with aspirin recommended. Among the high-risk IMiDs patients, 43% (30/69) currently received a VTE prophylaxis after starting their first regimen: 70% LWMH (21/30), 40% VKA (12/30), 10% UFH (3/30) and 13% (4/30) other drugs (rivaroxaban and fondaparinux); 33% of the patients (23/69) received an antiplatelet drug only, and 23% (16/69) did not receive any antithrombotic drug.

CONCLUSIONS

These results revealed lack of implementation of VTE prophylaxis in one out of high-risk multiple myeloma patients with IMiD. Copyright © 2017 John Wiley & Sons, Ltd.

Drug-Induced Thrombophilic or Prothrombotic States: An Underestimated Clinical Problem That Involves Both Legal and Illegal Compounds

Vascular thrombosis, both arterial and venous, is a condition associated with significant morbidity and mortality. There are multiple risk factors for thrombosis, both congenital and acquired, and in the majority of cases, these risk factors are not modifiable. Over the past 2 decades, multiple drugs (both illegal and legal) have been associated with increased risk of thrombosis. However, due to limited scientific literature regarding the prothrombotic tendencies of these drugs, there is a concomitant limited understanding of the pathophysiology of drug-induced thrombosis. As drugs are one of the few modifiable risk factors for thrombosis, further study and dissemination of knowledge regarding drug-associated and drug-induced thrombosis are essential and have the potential to lead to decreased future incidence of thrombosis. The mechanisms at the basis of the thrombophilic activity of these drugs are variable and sometimes still ill recognized. Increased levels of clotting factors, reduction in coagulation natural inhibitors, decreased fibrinolysis, activated clotting factors, increased blood viscosity, endothelial damage, and increased platelet number and activation are the most frequent causes. Arterial steal or coronary arteries no flow has also been implicated. In some cases due to the intake of several drugs, more than one mechanism is present in a given patient. The purpose of the present review is to analyze all the drugs demonstrated to be potentially thrombotic. It is hoped that a prudent use or nonuse of these drugs might result in a reduction of thrombosis-associated diseases.

A Case of Internal Carotid Artery Thrombosis associated with Thalidomide Administration in Multiple Myeloma

Thalidomide is an effective chemotherapeutic agent used to achieve remission in multiple myeloma. However, its administration is associated with several adverse effects including venous thromboembolism, while arterial thrombosis has also, although rarely, been described in the literature. We report a case of internal carotid artery occlusion within 1 week of starting thalidomide with prophylactic low molecular weight heparin in a patient who had no other prothrombotic risk factors. It is not known why this complication occurs despite the administration of anticoagulant prophylaxis. The role of factor VIII, von Willebrand factor antigen levels and fibrinogen in multiple myeloma patients should be studied in order to determine if these factors should be targeted in future prophylactic treatment.

Venous and arterial thrombotic risks with thalidomide: evidence and practical guidance

Oral immunomodulatory drugs (IMiDs), namely thalidomide, lenalidomide and pomalidomide, interfere with several pathways important for disease progression. Today they play a crucial role in the treatment of multiple myeloma patients, and have considerably improved myeloma outcomes. These agents, and thalidomide in particular, are associated with higher rates of thromboembolic events, both venous and arterial. Individual risk factors for thromboembolic events include advanced age, previous history of thromboembolism, an indwelling central venous catheter, comorbid conditions (e.g. infections, diabetes, cardiac disease, obesity), current or recent immobilization, recent surgery and inherited thrombophilic abnormalities. Cancer therapy and cancer itself also increase the risk of thromboembolic events. The aim of this review is to help clinicians to define the risk of thrombotic events in patients treated with thalidomide and thus to provide practical recommendations to manage thromboprophylaxis in these patients.

The rise, fall and subsequent triumph of thalidomide: lessons learned in drug development

Perhaps no other drug in modern medicine rivals the dramatic revitalization of thalidomide. Originally marketed as a sedative, thalidomide gained immense popularity worldwide among pregnant women because of its effective anti-emetic properties in morning sickness. Mounting evidence of human teratogenicity marked a dramatic fall from grace and led to widespread social, legal and economic ramifications. Despite its tragic past thalidomide emerged several decades later as a novel and highly effective agent in the treatment of various inflammatory and malignant diseases. In 2006 thalidomide completed its remarkable renaissance becoming the first new agent in over a decade to gain approval for the treatment of plasma cell myeloma. The catastrophic collapse yet subsequent revival of thalidomide provides important lessons in drug development. Never entirely abandoned by the medical community, thalidomide resurfaced as an important drug once the mechanisms of action were further studied and better understood. Ongoing research and development of related drugs such as lenalidomide now represent a class of irreplaceable drugs in hematological malignancies. Further, the tragedies associated with this agent stimulated the legislation which revamped the FDA regulatory process, expanded patient informed consent procedures and mandated more transparency from drug manufacturers. Finally, we review recent clinical trials summarizing selected medical indications for thalidomide with an emphasis on hematologic malignancies. Herein, we provide a historic perspective regarding the up-and-down development of thalidomide. Using PubMed databases we conducted searches using thalidomide and associated keywords highlighting pharmacology, mechanisms of action, and clinical uses.

Defibrotide blunts the prothrombotic effect of thalidomide on endothelial cells

Patients with multiple myeloma (MM) are at relatively high risk of developing thromboembolic events such deep venous thrombosis (DVT) where thalidomide therapy has been identified to increase this risk. Defibrotide (DF), a polydisperse oligonucleotide, showed previously to counteract the alterations in endothelial cells (ECs) induced by lipopolysaccharide. It prompts us to investigate the impact of thalidomide on ECs and whether DF modulates changes in fibrinolysis induced by thalidomide. In this in vitro study, MM by itself alters the profibrinolytic potential of ECs decreasing the tissue plasminogen activator (t-PA) and increasing the plasminogen activator inhibitor 1 (PAI-1) levels which is potentiated by thalidomide. Defibrotide was able to counteract these effects. Additionally, DF upregulated the t-PA and downregulated PAI-1 gene expression modulated by thalidomide. Defibrotide also protects ECs from thalidomide-mediated cell death without interfering with its antitumor effects. These findings support DF clinical use for the prevention of DVT induced by immunomodulatory drugs.

High incidence of arterial thrombosis in young patients treated for multiple myeloma: results of a prospective cohort study

This prospective study evaluated the risk of arterial thrombosis in 195 consecutive patients aged 18 to 65 years with newly diagnosed multiple myeloma (MM). All patients were treated with 3 cycles of VAD (vincristine, doxorubicin, and dexamethasone) or TAD (thalidomide-AD) or PAD (bortezomib-AD) in national trials, followed by high-dose melphalan and autologous stem cell transplantation. For a period of 522 patient-years, 11 of the 195 patients (5.6%) developed arterial thrombosis. The highest incidence was seen during induction chemotherapy courses. Median age at onset of arterial thrombosis was 59 years (range, 43-65 years). Hypertension and smoking were significantly associated with arterial thrombosis with a relative risk of 11.7 (2.23-61.2) and 15.2 (1.78-130), respectively. Factor VIII levels (FVIII:C) correlated significantly with age (P = .02) and higher International Scoring System (ISS) stage (P = .001). A higher FVIII:C was associated with arterial thrombosis (hazard ratio [HR] = 1.85; 95% confidence interval [CI] = 0.99-3.47) after adjustment for age, ISS score, and assigned treatment arm. MM patients have an increased risk for arterial thrombotic events during and after induction chemotherapy. Hypertension, smoking, and high factor VIII levels, possibly reflecting disease activity, contribute to the risk of arterial thrombosis.

Risk of cardiac ischemia and arterial thromboembolic events with the angiogenesis inhibitor bevacizumab in cancer patients: a meta-analysis of randomized controlled trials

BACKGROUND

The risk of cardiovascular toxicities is a serious concern with the increased application of angiogenesis inhibitors in current cancer therapy. Arterial thromboembolic events (ATE) were associated with bevacizumab, an antibody against vascular endothelial growth factor. To determine the risk of ATE including cardiac ischemia and stroke, a systematic review and meta-analysis of published randomized controlled trials (RCTs) was performed.

METHODS

We searched the databases of PubMed, Web of Science, and American Society of Clinical Oncology conferences to identify relevant clinical trials up to May, 2009. Eligible studies included prospective RCTs in which bevacizumab was compared to a control concurrently in combination with standard anti-neoplastic therapy. Summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) were calculated using random-effects or fixed-effects models.

RESULTS

A total of 12 617 patients with a variety of advanced solid tumors from 20 RCTs were included for analysis. The incidences of all-grade and high-grade ATE in patients receiving bevacizumab were 3.3% (95% CI, 2.0-5.6%) and 2.0% (95% CI, 1.7-2.5) respectively. Patients treated with bevacizumab had a significantly increased risk of ATE with an RR of 1.44 (95% CI, 1.08-1.91; p=0.013) compared with controls. The risk similarly increased for bevacizumab at 2.5 and 5 mg/kg/week; in addition, significantly increased risks were observed in patients with renal cell cancer (RR, 3.72, 95% CI, 1.15-12.04; p=0.029) and colorectal cancer (RR, 1.89, 95% CI, 1.28-2.80, p=0.001). Notably, the risk of high-grade cardiac ischemia with bevacizumab was significantly higher than controls with an RR of 2.14 (95% CI, 1.12-4.08, p=0.021); however, the risk of ischemic stroke with bevacizumab was not significantly different from controls (RR, 1.37, 95% CI, 0.67-2.79, p=0.39).

DISCUSSION

Treatment with bevacizumab may significantly increase the risk of cardiac ischemic events in cancer patients.

Arterial and venous thrombosis in monoclonal gammopathy of undetermined significance and multiple myeloma: a population-based study

Patients with multiple myeloma (MM) have an increased risk of venous thrombosis. Interestingly, excess risk of venous thromboembolism has been observed among patients with monoclonal gammopathy of undetermined significance (MGUS). Using population-based data from Sweden, we assessed the risks of venous and arterial thrombosis in 18,627 MM and 5326 MGUS patients diagnosed from 1958 to 2006, compared with 70,991 and 20,161 matched controls, respectively. At 1, 5, and 10 years after MM diagnosis, there was an increased risk of venous thrombosis: hazard ratios (95% confidence intervals) were 7.5 (6.4-8.9), 4.6 (4.1-5.1), and 4.1 (3.8-4.5), respectively. The corresponding results for arterial thrombosis were 1.9 (1.8-2.1), 1.5 (1.4-1.6), and 1.5 (1.4-1.5). At 1, 5, and 10 years after MGUS diagnosis, hazard ratios were 3.4 (2.5-4.6), 2.1 (1.7-2.5), and 2.1 (1.8-2.4) for venous thrombosis. The corresponding risks for arterial thrombosis were 1.7 (1.5-1.9), 1.3 (1.2-1.4), and 1.3 (1.3-1.4). IgG/IgA (but not IgM) MGUS patients had increased risks for venous and arterial thrombosis. Risks for thrombosis did not vary by M-protein concentration (> 10.0 g/L or < 10.0 g/L) at diagnosis. MGUS patients with (vs without) thrombosis had no excess risk of MM or Waldenström macroglobulinemia. Our findings are of relevance for future studies and for improvement of thrombosis prophylaxis strategies.

Arterial thrombosis with immunomodulatory derivatives in the treatment of multiple myeloma: a single-center case series and review of the literature

Although the increased risk of venous thrombotic events with thalidomide in multiple myeloma (MM) has been well described, an association with an increased risk of arterial events is less well appreciated. We describe 5 unusual arterial thromboses in patients with MM shortly after beginning thalidomide-based therapies. The cases are remarkable for a paucity of risk factors and short latency. We also review the literature on arterial thromboembolic events in patients taking thalidomide. Care should be taken in future trials to document arterial events with both thalidomide and lenalidomide.

Low incidence of clinically apparent thromboembolism in Korean patients with multiple myeloma treated with thalidomide

The frequency of thromboembolic events (TE) in Caucasian patients with multiple myeloma (MM) receiving thalidomide as the initial treatment has been reported to be 10~58% without prophylactic anticoagulation. Korean MM patients treated with thalidomide were studied to determine the frequency of TE and associated risk factors. A retrospective medical record review of the Korean MM registry from 25 centers in Korea between 2003 and 2007 was performed. We assessed the incidence of arterial and venous TE and the associated clinical parameters. Three hundred and sixty MM patients (median age 61 years, range 32-88 years) received thalidomide treatment. Fourteen patients (3.9%) developed TE: 12 had venous and two had arterial locations. The sites for the venous TE included lungs (seven), lower extremities (four), upper extremities (one), and neck (one). Arterial TE developed in cerebral and peripheral arteries each. No single clinical parameter such as prerequisite for the metabolic syndrome, disease status, and treatment regimen were predictive for the development of TE. The frequency of TE in patients who received thalidomide as initial therapy (7/155) was not different from those who received thalidomide for progressive or relapsed disease (7/205, p = 0.592). The frequency of TE during thalidomide treatment in Korean patients with MM was low. No significant clinical factor was found to be a risk factor. The subgroup requiring thromboprophylaxis among the Korean patients with MM, receiving thalidomide, needs to be clarified.

Multifocal Arterial Thrombosis during Thalidomide Therapy: Case Report and Review of the Literature

Introduction. Thalidomide has been associated with both venous and arterial thrombotic events. Case Presentation. A 66-years old man during thalidomide therapy for myeloma experienced acute right arm ischemia, emergently treated with thrombectomy and, on postoperative day one left side weakness with right internal carotid thrombosis. Discussion. Because of the increased risk of arterial thrombosis complication, prophylactic therapy with ASA or anticoagulation during thalidomide administration is mandatory.

Genetic associations with thalidomide mediated venous thrombotic events in myeloma identified using targeted genotyping

A venous thromboembolism (VTE) with the subsequent risk of pulmonary embolism is a major concern in the treatment of patients with multiple myeloma with thalidomide. The susceptibility to developing a VTE in response to thalidomide therapy is likely to be influenced by both genetic and environmental factors. To test genetic variation associated with treatment related VTE in patient peripheral blood DNA, we used a custom-built molecular inversion probe (MIP)-based single nucleotide polymorphism (SNP) chip containing 3404 SNPs. SNPs on the chip were selected in "functional regions" within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and side effects associated with myeloma therapy. Patients and controls were taken from 3 large clinical trials: Medical Research Council (MRC) Myeloma IX, Hovon-50, and Eastern Cooperative Oncology Group (ECOG) EA100, which compared conventional treatments with thalidomide in patients with myeloma. Our analysis showed that the set of SNPs associated with thalidomide-related VTE were enriched in genes and pathways important in drug transport/metabolism, DNA repair, and cytokine balance. The effects of the SNPs associated with thalidomide-related VTE may be functional at the level of the tumor cell, the tumor-related microenvironment, and the endothelium. The clinical trials described in this paper have been registered as follows: MRC Myeloma IX: ISRCTN68454111; Hovon-50: NCT00028886; and ECOG EA100: NCT00033332.

Arterial thrombosis and thalidomide

Arterial emboli are largely a reflection of cardiac disease. Thalidomide is an antiangiogenic drug used in cancer therapy. Venous thrombosis incidence increased during treatment with thalidomide. We reported arterial thrombosis in two cases with multiple myeloma implemented in thalidomide treatment. Standard emergency intervention was applied. In the postoperative period, enoxiparine was given to all the patients. Warfarin treatment was started in the level of INR 2-2,5. ASA with a dose of 100 mg/day was added to the treatment. In conclusion, this side effect of the use of thalidomide should be taken into consideration while doing examinations with respect to the etiology in arterial thromboembolism and because of this vascular complication that threatens life; we suggest stopping the thalidomide treatment.

Stroke in a multiple myeloma patient treated with thalidomide

The antiangiogenic and immunomodulatory properties of thalidomide have led to its use and evaluation in refractory or relapsed multiple myeloma (MM). However, thalidomide use is associated with several side effects, although deep vein thrombosis and peripheral neuropathy are the most serious. The incidence of thrombosis after treatment with thalidomide ranges from 2% to 23%, but is higher among patients who also receive chemotherapy. Thromboembolic episodes are usually venous and may cause pulmonary embolism or even myocardial infarction and cerebral venous thrombosis. Arterial occlusion is rare, and the association between arterial thrombotic events and thalidomide is infrequent with only a few patients reported who developed arterial strokes on thalidomide. We describe a case of nonfatal thrombotic stroke occurring in a patient with relapsed MM treated with thalidomide.

[Thromboembolic risk associated with use of angiogenesis inhibitors used for the treatment of cancers]

Among antiangiogenic agents, thalidomide is not the most potent nor the most specific even so when venous thromboembolic events have been reported with the prescription of thalidomide in multiple myeloma. This side effect has been related to the antiangiogenic effect of this immunomodulator. In keeping with this observation venous thromboembolic events have been reported in other indications of thalidomide and with thalidomide analogues (Lenalidomide and Actimid). The thrombotic side effects are mostly venous but arterial thrombotic events are also observed with the use of these molecules. With the other and more specific antiagiogenic agents an increase in thrombotic events are also observed. This increase was not immediately evident since the situation in which they are prescribed (metastatic cancers) are already characterized by a high rate of thrombotic events. The prothrombotic effect of antiangiogenic agents are probably linked to an effect on endothelium (decrease of antithrombotic activities and stimulation of a prothrombotuic state). The other sides effects of antiangiogenic agents (hemorrhages, hypertension, proteinuria, microangiotpahia, delay in scaring) are also probably related to endothelial effects. The prothrombotic effect of antoangiogenic agents appears as potentiating the prothrombotic conditions of the disease (myeloma, cancer) and the prothombotic effects of the associated treatments (chemotherapy, high dose corticosteroids, erythropoietin). The increased thrombotic risk linked to prescription of antiangiogenic agents and specially of thalidomide and analogues for multiple myeloma is such that it is recommended to associate a preventive antithrombotic treatment. Some efficacy has been reported with the use of aspirin, oral anticoagulant or low molecular weight heparin. No head to head comparative trial do not allow to prefer one strategy. From published data full dose oral anticoagulants appear to confer the highest hemorrhagic risk and perhaps low molecular weight heparin the best benefit-risk ratio.

Management of stroke in cancer

Cerebrovascular disorders, including brain infarction, brain hemorrhage, and cerebral venous thrombosis, can occur as an early sign of cancer, but typically occur late in the clinical course. These disorders are due to a variety of pathogenic mechanisms, including coagulation disorders associated with the cancer, invasion or compression of vessels from tumor in or adjacent to the brain, and the adverse effects of cancer therapy. The appropriate therapy for these cerebrovascular disorders is empiric in most instances, because as yet there are no prospective treatment trials for them. A review of the existing literature reveals that improvement in patient quality of life and prevention of further cerebrovascular events can be obtained in some clinical situations.

Complications from vascular disrupting agents and angiogenesis inhibitors: aberrant control of hemostasis and thrombosis

PURPOSE OF REVIEW

To discuss thrombotic and hemorrhagic complications from angiogenesis inhibitors and vascular disrupting agents, pathogenesis, and recommendations for prophylaxis and management of those complications.

RECENT FINDINGS

Venous thromboembolism has been a significant complication of the angiogenesis inhibitors thalidomide and lenalidomide. Prophylaxis with aspirin, low-molecular-weight heparin, or warfarin has been shown to decrease rates of venous thromboembolism in patients treated with these agents. Life-threatening hemorrhage and arterial thromboembolism have been observed in patients using treatments that inhibit the vascular endothelial growth factor signaling pathway. Patients should be screened for arterial thromboembolism and hemorrhage risk prior to using vascular endothelial growth factor signal inhibitors. It is not known how angiogenesis inhibitors and vascular disrupting agents upset normal hemostasis. It is likely that disruption of the function and/or integrity of vascular endothelium leads to an increased risk for thrombosis and/or hemorrhage.

SUMMARY

New angiogenesis inhibitors and vascular disrupting agents have been developed that have significant activity against neoplasms. Potentially life-threatening side effects of hemorrhage and thrombosis have been observed with many of these new agents. As new treatments that disrupt angiogenesis or existing tumor vasculature are developed, attention should be given to these toxicities in clinical practice and clinical trials.

Neglected respiratory toxicity caused by cancer therapy

When a patient with lung cancer presents non-specific respiratory symptoms there are many diagnostic options. Chemotherapy is the cornerstone of treatment in many stages of lung cancer and its toxicity is well known. The main priority is to prevent life-threatening diseases such as lung infection, which can be treated successfully if a prompt, accurate diagnosis is given. Drug-induced pulmonary disease must be avoided at all costs but it is also important to avoid side-effects of drugs which do not directly interfere with respiratory physiology but may impair gas exchange. This review highlights the risks and characteristics of non-cytostatic-induced lung toxicity caused by agents that have been commonly used to treat cancer in recent decades. Physicians should be alert to the possibility of this neglected non-chemotherapy-induced lung toxicity in cancer patients, since early withdrawal of the offending drug is mandatory.

Supportive care in multiple myeloma

Significant progress in the treatment of multiple myeloma has resulted in improvement of disease control with a trend toward overall and progression-free survival benefit. With the availability of several new therapeutic agents and combinations, a careful emphasis should be placed in the management of disease- and therapy-associated complications. Aggressive management of these complications can impact patients' quality of life as well as treatment outcome. This review highlights some of the critical supportive care measures integral to the optimal care of patients with multiple myeloma.

Low tolerance and high toxicity of thalidomide as maintenance therapy after double autologous stem cell transplant in multiple myeloma patients

Although a double autologous peripheral blood stem cell transplant (APBSCT) is an effective therapy for patients (pts) with multiple myeloma and extends progression-free survival and overall survival, pts show a continued pattern of recurrent disease. The feasibility and tolerability of thalidomide (Thal) administered in the post-transplantation period as maintenance therapy was tested in 17 pts at a dose of 100 mg/d starting between 3 and 5 months after the second transplantation and continuing either until toxicity precluded further therapy or until pts had disease progression. After a median administration of 13 months (range: 3-26), 76.5% (13 pts) failed to tolerate Thal because of: transiet ischemic attack (three pts), severe fatigue (two), neutropenia (one), piastrinopenia (one), severe opportunistic infectious (two), erectile impotence (one), gastrointestinal toxicity (anorexia with weight loss one), peripheral neuropathy (two). After a median follow-up of 36 months (range: 10-59) from the second transplant, 13 patients attained a CR + near CR (with a conversion rate from 47.1% to 76.5%). In conclusion, Thal as maintenance therapy after double ASCT is associated with low feasibility and high toxicity and could prevent a lengthy use of this antineoplastic agent.

Maintenance thalidomide following single cycle autologous peripheral blood stem cell transplant in patients with multiple myeloma

Although autologous stem cell transplant is an effective therapy for patients with multiple myeloma and extends progression-free survival (PFS) and overall survival (OS), patients show a continued pattern of recurrent disease. Twenty-nine patients were enrolled in a phase II study investigating the tolerability and efficacy of maintenance thalidomide following single autologous peripheral blood stem cell transplant. Six to eight weeks after transplant, patients were started on maintenance thalidomide at 50 mg a day. The dose was gradually escalated to a target dose of 400 mg a day and continued until disease progression or 6 months after achieving complete remission (CR) for a maximum total duration of 18 months. At 6 months, 13 patients (45%) achieved CR or near complete remission (positive immunofixation without any evidence of disease). The estimated 2-year OS was 83% and PFS was 49%. Median tolerated dose of thalidomide was 200 mg a day. In conclusion, thalidomide as maintenance therapy is feasible and may improve outcome after single autologous stem cell transplant.

Thrombotic Complications of Myeloma Therapy

Patients with multiple myeloma are at relatively high baseline risk of developing thromboembolic events (TEE), usually deep vein thromboses. There are numerous contributing factors, among them certain treatment regimens that include thalidomide or related compounds such as lenalidomide combined with glucocorticoids and/or cytotoxic chemotherapy. The risk of developing TEE appears to be particularly high when these immunomodulatory agents are combined with anthracyclines as treatment of newly-diagnosed disease. Up-front combinations including thalidomide plus pulse dexamethasone and/or alkylating agents are associated with an intermediate risk, whereas the same regimens for relapsed/refractory myeloma seem to be associated with the lowest risk. Several different thromboprophylaxis strategies have been effective in lowering the risk of developing clots: daily aspirin (81–325 mg/day), full-intensity warfarin (INR 2–3), and prophylactic enoxaparin (40 mg SQ daily). Low, fixed-dose warfarin may also reduce the risk of TEE, but the data on this are disputable. None of these TEE prevention strategies have been prospectively compared head-to-head, so the choice often reflects physician and/or patient preferences. The available evidence upon which one might make such a decision is reviewed here.

Targeted therapy in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is an incurable malignancy. Recent insights into its biology has allowed the use of novel therapies targeting not only the deregulated intracellular signaling in MM cells but also its interaction with the bone marrow microenvironment that confers drug resistance, growth, and survival advantage to the malignant cells.

METHODS

We review and summarize the recent advances in our knowledge of myeloma biology as well as the mechanism of action and clinical efficacy for novel therapeutic agents in clinical trials.

RESULTS

Several novel therapeutic agents are currently in clinical trials. Thalidomide is already established for both initial and salvage treatment. Bortezomib is being tested alone and in combination with conventional chemotherapy in various settings. Other agents are less effective in producing response but have been able to stabilize disease in patients with relapsed and/or refractory disease, such as arsenic trioxide, farnesyltransferase inhibitors, 2-methoxyestradiol, and vascular endothelial growth factor receptor inhibitors. Insights into drug resistance mechanism have also led to the development of novel agents that sensitize myeloma cells to chemotherapy (Bcl-2 antisense). Gene expression studies have in many instances identified pathways other than the intended target of the drug and have provided insights into the therapeutic mechanisms.

CONCLUSIONS

In the future, patients with MM will have more therapeutic options available than ever before. The challenge will be to identify patient subgroups that will benefit most from the different therapies and then determine how these biologically based therapies could be combined and incorporated into the overall management of patients.

The combination of intermediate doses of thalidomide with dexamethasone is an effective treatment for patients with refractory/relapsed multiple myeloma and normalizes abnormal bone remodeling, through the reduction of sRANKL/osteoprotegerin ratio

The aim of this study was the evaluation of the effect of intermediate doses of thalidomide with dexamethasone (Thal/Dex) on disease course and bone disease in patients with refractory/relapsed myeloma who were under zoledronic acid therapy. We studied 35 patients, who received thalidomide at a dose of 200 mg/daily. We measured, pre-, 3 and 6 months post-treatment soluble receptor activator of nuclear factor-kappaB ligand (sRANKL), osteoprotegerin (OPG), osteopontin (OPN), markers of bone resorption and formation. Before treatment, patients had increased levels of sRANKL/OPG ratio, bone resorption markers and OPN, while they had suppressed bone formation. The pretreatment sRANKL/OPG ratio correlated with the extent of bone disease. Thal/Dex administration resulted in a significant reduction of sRANKL/OPG ratio, and bone resorption. Bone formation, OPG and OPN did not show any alteration. Changes of sRANKL/OPG ratio correlated with changes of bone resorption markers. Thal/Dex was given for a median time of 10 months and the median follow-up period was 22 months. The response rate was 65.7%. The median survival was 19.5 months. beta2-microglobulin, type of response and International Staging System predicted for survival. These results suggest that the combination of intermediate dose of Thal/Dex is effective in patients with refractory/relapsed myeloma and improves abnormal bone remodeling through the reduction of sRANKL/OPG ratio.