Recurrent cardiotoxicity potentiated by the interaction of proteasome inhibitor and immunomodulatory therapy for the treatment of multiple myeloma

Use of new and emerging cancer drugs: what the cardiologist needs to know

The last decade has witnessed a paradigm shift in cancer therapy, from non-specific cytotoxic chemotherapies to agents targeting specific molecular mechanisms. Nonetheless, cardiovascular toxicity of cancer therapies remains an important concern. This is particularly relevant given the significant improvement in survival of solid and haematological cancers achieved in the last decades. Cardio-oncology is a subspecialty of medicine focusing on the identification and prevention of cancer therapy-related cardiovascular toxicity (CTR-CVT). This review will examine the new definition of CTR-CVT and guiding principles for baseline cardiovascular assessment and risk stratification before cancer therapy, providing take-home messages for non-specialized cardiologists.

Heartbreaker: Detection and prevention of cardiotoxicity in hematological malignancies

Cancer survivors are at significant risk of cardiovascular (CV) morbidity and mortality; patients with hematologic malignancies have a higher rate of death due to heart failure compared to all other cancer subtypes. The majority of conventional hematologic cancer treatments is associated with increased risk of acute and long-term CV toxicity. The incidence of cancer therapy induced CV toxicity depends on the combination of patient characteristics and on the type, dose, and duration of the therapy. Early diagnosis of CV toxicity, appropriate referral, more specific cardiac monitoring follow-up and timely interventions in target patients can decrease the risk of CV adverse events, the interruption of oncological therapy, and improve the patient's prognosis. Herein, we summarize the CV effects of conventional treatments used in hematologic malignancies with a focus on definitions and incidence of the most common CV toxicities, guideline recommended early detection approaches, and preventive strategies before and during cancer treatments.

Cardiovascular toxicity from therapies for light chain amyloidosis

Amyloid light-chain (AL) amyloidosis is a hematological disorder characterized by abnormal proliferation of a plasma cell clone producing monoclonal free light chains that misfold and aggregate into insoluble fibrils in various tissues. Cardiac involvement is a common feature leading to restrictive cardiomyopathy and poor prognosis. Current first-line treatments aim at achieving hematological response by targeting the plasma cell clones, and these have been adapted from multiple myeloma therapy. Patients with AL amyloidosis often exhibit multiorgan involvement, making them susceptible to cancer therapy-related cardiovascular toxicity. Managing AL amyloidosis is a complex issue that requires enhanced knowledge of the cardio-oncological implications of hematological treatments. Future research should focus on implementing and validating primary and secondary prevention strategies and understanding the biochemical basis of oncological therapy-related damage to mitigate cardiovascular toxicity.

Cardiovascular Toxicity of Proteasome Inhibitors in Multiple Myeloma Therapy

The treatment for multiple myeloma has advanced significantly over the past few decades. Proteasome inhibitors have become the cornerstone of the treatment of multiple myeloma. However, proteasome inhibitors have shown cardiovascular complications such as hypertension, pulmonary hypertension, heart failure, arrhythmias, ischaemic heart disease and thromboembolism. Detection, monitoring and management of proteasome inhibitor-related cardiovascular toxicity are essential to improve clinical outcomes for patients. Proposed mechanisms of proteasome inhibitor-related cardiovascular toxicity are apoptosis, prolonged inhibition of the ubiquitin-proteasome system, accumulation of improperly folded proteins within cardiomyocytes and higher protein phosphatase 2A activity. To better understand the mechanisms underlying cardiotoxicity, further in vitro and in vivo experiments are required to investigate these hypotheses. Combined use of metformin or angiotensin II receptor blockers with the proteasome inhibitor, carfilzomib, showed an emerging role as a prophylactic therapy because they can preserve heart function in multiple myeloma patients. Metformin is expected to be an effective therapeutic intervention for the management of carfilzomib-induced cardiotoxicity. There has been evidence that three compounds, apremilast, rutin, and dexrazoxane, can reverse carfilzomib-induced cardiotoxicity in rats. The future transition from animal experiments to clinical trials is worth waiting for.

Molecular Cardiotoxic Effects of Proteasome Inhibitors Carfilzomib and Ixazomib and Their Combination with Dexamethasone Involve Mitochondrial Dysregulation

With the development and approval of new proteasome inhibitors, proteasome inhibition is increasingly recognized in cancer therapy. Besides successful anti-cancer effects in hematological cancers, side effects such as cardiotoxicity are limiting effective treatment. In this study, we used a cardiomyocyte model to investigate the molecular cardiotoxic mechanisms of carfilzomib (CFZ) and ixazomib (IXZ) alone or in combination with the immunomodulatory drug dexamethasone (DEX) which is frequently used in combination therapies in the clinic. According to our findings, CFZ showed a higher cytotoxic effect at lower concentrations than IXZ. DEX combination attenuated the cytotoxicity for both proteasome inhibitors. All drug treatments caused a marked increase in K48 ubiquitination. Both CFZ and IXZ caused an upregulation in cellular and endoplasmic reticulum stress protein (HSP90, HSP70, GRP94, and GRP78) levels and DEX combination attenuated the increased stress protein levels. Importantly, IXZ and IXZ-DEX treatments caused upregulation of mitochondria fission and fusion gene expression levels higher than caused by CFZ and CFZ-DEX combination. The IXZ-DEX combination reduced the levels of OXPHOS proteins (Complex II-V) more than the CFZ-DEX combination. Reduced mitochondrial membrane potential and ATP production were detected with all drug treatments in cardiomyocytes. Our findings suggest that the cardiotoxic effect of proteasome inhibitors may be due to their class effect and stress response and mitochondrial dysfunction may be involved in the cardiotoxicity process.

Pretreatment serum level of interleukin-6 predicts carfilzomib-induced hypertension in relapsed/refractory multiple myeloma

Carfilzomib (CFZ) constitutes powerful combinatory therapy for relapsed/refractory multiple myeloma (RRMM); however, cardiovascular adverse events (CVAEs) have been shown as major treatment obstacles with the use of CFZ. Along with our multi-institutional prospective observational study by the Kyoto Clinical Hematology Study Group on the efficacy and safety of CFZ-based treatments (UMIN000025108), we here performed an ad hoc analysis of CFZ-related CVAEs in 50 patients with RRMM. We analyzed the association between CFZ-related CVAEs and pre-planned examinations, including patients' background, electrocardiographic findings, echocardiographic findings, and serum/plasma levels of 18 potential candidate biomarkers. The common CVAEs were hypertension (42%), arrhythmia (14%), and prolongation of QT corrected interval (10%), whereas no serious CVAEs occurred. The pretreatment serum level of interleukin-6 was identified as a significant risk factor for CFZ-related hypertension. This study revealed hypertension as the most frequent CFZ-related CVAE and suggested that baseline serum interleukin-6 is a useful predictor for CFZ-induced hypertension.

Cardiotoxicity as an adverse effect of immunomodulatory drugs and proteasome inhibitors in multiple myeloma: A network meta-analysis of randomized clinical trials

We aim to determine the cumulative and comparative risk of cardiovascular events associated with different Immunomodulatory Drugs (iMiDs) and Proteasome Inhibitor (PIs) in Multiple Myeloma (MM) patients through pairwise and network meta-analysis. Electronic searches were conducted using Ovid MEDLINE, EMBASE, CINAHL, Web of Science, and Clinical Trial Registry (Clinical Trials.gov) up to May 2021. Phase 3 randomized clinical trials (RCTs) reporting cardiotoxicity in MM patients (newly diagnoses and/or relapsed) treated with iMiD and/or PI. Studies, where iMiD or PI was used alongside the chemotherapy versus placebo or no additional drugs (control) in the other arm were included. The primary outcome was the presence of cardiotoxicity after follow-up. Pairwise meta-analysis and network meta-analysis were performed using the frequentist's approach to estimate the odds ratio (OR). Twenty RCTs with 10,373 MM patients were included in this analysis. Eleven studies compared iMiDs with control, seven studies compared PIs with control, and two studies compared bortezomib against carfilzomib. CTACE high-grade (≥grade 3) cardiotoxic events were increased with iMiDs compared to their control counterpart (OR 2.05; 95% CI 1.30-3.26). Similar high-grade cardiotoxicity was also noted more frequently with PI use when compared to the control group (OR 1.67; 95% CI 1.17-2.40). Among the PIs, carfilzomib was associated with a maximum risk of cardiotoxicity (OR 2.68; 95% CI 1.63-4.40). There was no evidence of publication bias among studies. iMiDs and PIs, particularly carfilzomib, appear to be associated with increased risk of high-grade cardiovascular events in MM patients.

Antithrombotic therapy for ambulatory patients with multiple myeloma receiving immunomodulatory agents

BACKGROUND

Multiple myeloma is a malignant plasma cell disorder characterised by clonal plasma cells that cause end-organ damage such as renal failure, lytic bone lesions, hypercalcaemia and/or anaemia. People with multiple myeloma are treated with immunomodulatory agents including lenalidomide, pomalidomide, and thalidomide. Multiple myeloma is associated with an increased risk of thromboembolism, which appears to be further increased in people receiving immunomodulatory agents.

OBJECTIVES

(1) To systematically review the evidence for the relative efficacy and safety of aspirin, oral anticoagulants, or parenteral anticoagulants in ambulatory patients with multiple myeloma receiving immunomodulatory agents who otherwise have no standard therapeutic or prophylactic indication for anticoagulation. (2) To maintain this review as a living systematic review by continually running the searches and incorporating newly identified studies.

SEARCH METHODS

We conducted a comprehensive literature search that included (1) a major electronic search (14 June 2021) of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE via Ovid, and Embase via Ovid; (2) hand-searching of conference proceedings; (3) checking of reference lists of included studies; and (4) a search for ongoing studies in trial registries. As part of the living systematic review approach, we are running continual searches, and we will incorporate new evidence rapidly after it is identified.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the benefits and harms of oral anticoagulants such as vitamin K antagonist (VKA) and direct oral anticoagulants (DOAC), anti-platelet agents such as aspirin (ASA), and parenteral anticoagulants such as low molecular weight heparin (LMWH)in ambulatory patients with multiple myeloma receiving immunomodulatory agents.

DATA COLLECTION AND ANALYSIS

Using a standardised form, we extracted data in duplicate on study design, participants, interventions, outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), major bleeding, and minor bleeding. For each outcome we calculated the risk ratio (RR) with its 95% confidence interval (CI) and the risk difference (RD) with its 95% CI. We then assessed the certainty of evidence at the outcome level following the GRADE approach (GRADE Handbook).

MAIN RESULTS

We identified 1015 identified citations and included 11 articles reporting four RCTs that enrolled 1042 participants. The included studies made the following comparisons: ASA versus VKA (one study); ASA versus LMWH (two studies); VKA versus LMWH (one study); and ASA versus DOAC (two studies, one of which was an abstract). ASA versus VKA One RCT compared ASA to VKA at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 3.00, 95% CI 0.12 to 73.24; RD 2 more per 1000, 95% CI 1 fewer to 72 more; very low-certainty evidence); symptomatic DVT (RR 0.57, 95% CI 0.24 to 1.33; RD 27 fewer per 1000, 95% CI 48 fewer to 21 more; very low-certainty evidence); PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence); major bleeding (RR 7.00, 95% CI 0.36 to 134.72; RD 6 more per 1000, 95% CI 1 fewer to 134 more; very low-certainty evidence); and minor bleeding (RR 6.00, 95% CI 0.73 to 49.43; RD 23 more per 1000, 95% CI 1 fewer to 220 more; very low-certainty evidence). One RCT compared ASA to VKA at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 0.50, 95% CI 0.05 to 5.47; RD 5 fewer per 1000, 95% CI 9 fewer to 41 more; very low-certainty evidence); symptomatic DVT (RR 0.71, 95% CI 0.35 to 1.44; RD 22 fewer per 1000, 95% CI 50 fewer to 34 more; very low-certainty evidence); and PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence). ASA versus LMWH Two RCTs compared ASA to LMWH at six months follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.81; RD 0 fewer per 1000, 95% CI 2 fewer to 38 more; very low-certainty evidence); symptomatic DVT (RR 1.23, 95% CI 0.49 to 3.08; RD 5 more per 1000, 95% CI 11 fewer to 43 more; very low-certainty evidence); PE (RR 7.71, 95% CI 0.97 to 61.44; RD 7 more per 1000, 95% CI 0 fewer to 60 more; very low-certainty evidence); major bleeding (RR 6.97, 95% CI 0.36 to 134.11; RD 6 more per 1000, 95% CI 1 fewer to 133 more; very low-certainty evidence); and minor bleeding (RR 1.42, 95% CI 0.35 to 5.78; RD 4 more per 1000, 95% CI 7 fewer to 50 more; very low-certainty evidence). One RCT compared ASA to LMWH at two years follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.89; RD 0 fewer per 1000, 95% CI 4 fewer to 68 more; very low-certainty evidence); symptomatic DVT (RR 1.20, 95% CI 0.53 to 2.72; RD 9 more per 1000, 95% CI 21 fewer to 78 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). VKA versus LMWH One RCT compared VKA to LMWH at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 0.33, 95% CI 0.01 to 8.10; RD 3 fewer per 1000, 95% CI 5 fewer to 32 more; very low-certainty evidence); symptomatic DVT (RR 2.32, 95% CI 0.91 to 5.93; RD 36 more per 1000, 95% CI 2 fewer to 135 more; very low-certainty evidence); PE (RR 8.96, 95% CI 0.49 to 165.42; RD 8 more per 1000, 95% CI 1 fewer to 164 more; very low-certainty evidence); and minor bleeding (RR 0.33, 95% CI 0.03 to 3.17; RD 9 fewer per 1000, 95% CI 13 fewer to 30 more; very low-certainty evidence). The study reported that no major bleeding occurred in either arm. One RCT compared VKA to LMWH at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 2.00, 95% CI 0.18 to 21.90; RD 5 more per 1000, 95% CI 4 fewer to 95 more; very low-certainty evidence); symptomatic DVT (RR 1.70, 95% CI 0.80 to 3.63; RD 32 more per 1000, 95% CI 9 fewer to 120 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). ASA versus DOAC One RCT compared ASA to DOAC at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to DOAC on DVT, PE, and major bleeding and minor bleeding (minor bleeding: RR 5.00, 95% CI 0.31 to 79.94; RD 4 more per 1000, 95% CI 1 fewer to 79 more; very low-certainty evidence). The study reported that no DVT, PE, or major bleeding events occurred in either arm. These results did not change in a meta-analysis including the study published as an abstract.

AUTHORS' CONCLUSIONS

The certainty of the available evidence for the comparative effects of ASA, VKA, LMWH, and DOAC on all-cause mortality, DVT, PE, or bleeding was either low or very low. People with multiple myeloma considering antithrombotic agents should balance the possible benefits of reduced thromboembolic complications with the possible harms and burden of anticoagulants. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Assessment and Management of Cardiotoxicity in Hematologic Malignancies

With the increasing overall survival of cancer patients due to recent discoveries in oncology, the incidence of side effects is also rising, and along with secondary malignancies, cardiotoxicity is one of the most concerning side effects, affecting the quality of life of cancer survivors. There are two types of cardiotoxicity associated with chemotherapy; the first one is acute, life-threatening but, fortunately, in most of the cases, reversible; and the second one is with late onset and mostly irreversible. The most studied drugs associated with cardiotoxicity are anthracyclines, but many new agents have demonstrated unexpected cardiotoxic effect, including those currently used in multiple myeloma treatment (proteasome inhibitors and immunomodulatory agents), tyrosine kinase inhibitors used in the treatment of chronic myeloid leukemia and some forms of acute leukemia, and immune checkpoint inhibitors recently introduced in treatment of refractory lymphoma patients. To prevent irreversible myocardial damage, early recognition of cardiac toxicity is mandatory. Traditional methods like echocardiography and magnetic resonance imaging are capable of detecting structural and functional changings, but unable to detect early myocardial damage; therefore, more sensible biomarkers like troponins and natriuretic peptides have to be introduced into the current practice. Baseline assessment of patients allows the identification of those with high risk for cardiotoxicity, while monitoring during and after treatment is important for early detection of cardiotoxicity and prompt intervention.

Cardiotoxicity of Novel Targeted Hematological Therapies

Chemotherapy-related cardiac dysfunction, also known as cardiotoxicity, is a group of drug-related adverse events negatively affecting myocardial structure and functions in patients who received chemotherapy for cancer treatment. Clinical manifestations can vary from life-threatening arrythmias to chronic conditions, such as heart failure or hypertension, which dramatically reduce quality of life of cancer survivors. Standard chemotherapy exerts its toxic effect mainly by inducing oxidative stress and genomic instability, while new targeted therapies work by interfering with signaling pathways important not only in cancer cells but also in myocytes. For example, Bruton’s tyrosine kinase (BTK) inhibitors interfere with class I phosphoinositide 3-kinase isoforms involved in cardiac hypertrophy, contractility, and regulation of various channel forming proteins; thus, off-target effects of BTK inhibitors are associated with increased frequency of arrhythmias, such as atrial fibrillation, compared to standard chemotherapy. In this review, we summarize current knowledge of cardiotoxic effects of targeted therapies used in hematology.

Onco-Cardiology: Consensus Paper of the German Cardiac Society, the German Society for Pediatric Cardiology and Congenital Heart Defects and the German Society for Hematology and Medical Oncology

The acute and long-lasting side effects of modern multimodal tumour therapy significantly impair quality of life and survival of patients afflicted with malignancies. The key components of this therapy include radiotherapy, conventional chemotherapy, immunotherapy and targeted therapies. In addition to established tumour therapy strategies, up to 30 new therapies are approved each year with only incompletely characterised side effects. This consensus paper discusses the risk factors that contribute to the development of a potentially adverse reaction to tumour therapy and, in addition, defines specific side effect profiles for different treatment groups. The focus is on novel therapeutics and recommendations for the surveillance and treatment of specific patient groups.

Primary prevention of venous thromboembolism with apixaban for multiple myeloma patients receiving immunomodulatory agents

Immunomodulatory drugs (IMiDs) have improved survival of patients with multiple myeloma (MM) and comprise the therapeutic backbone at all phases of therapy. Although well-tolerated, IMiDs increase rates of venous thromboembolism (VTE). In this phase IV, single-arm pilot study, fifty patients with MM on IMiDs received apixaban 2·5 mg orally twice daily for primary prevention of VTE and were prospectively monitored for six months. The primary safety outcomes were rates of major haemorrhage and clinically relevant non-major haemorrhage over six months. The primary efficacy outcome was the rate of symptomatic VTE over six months. IMiDs used were lenalidomide (58%) or pomalidomide (42%). During the six-month evaluation period, no patients experienced major haemorrhage or VTE. Three patients experienced clinically relevant, non-major haemorrhage which was managed medically, and all were able to resume apixaban. One patient stopped therapy shortly after initiation due to an allergic reaction to apixaban. No patients experienced stroke, myocardial infarction, or death. In this pilot study, low-dose apixaban was safe and well-tolerated as a primary prevention therapy of VTE for patients with MM receiving IMiDs. Further studies are needed to validate low-dose apixaban as a standard primary prevention anti-thrombotic strategy for patients with MM receiving IMiDs.

Prospective Study of Cardiac Events During Proteasome Inhibitor Therapy for Relapsed Multiple Myeloma

PURPOSE

Cardiovascular adverse events (CVAEs) can occur during proteasome inhibitor (PI) therapy. We conducted a prospective, observational, multi-institutional study to define risk factors and outcomes in patients with multiple myeloma (MM) receiving PIs.

PATIENTS AND METHODS

Patients with relapsed MM initiating carfilzomib- or bortezomib-based therapy underwent baseline assessments and repeated assessments at regular intervals over 6 months, including cardiac biomarkers (troponin I or T, brain natriuretic peptide [BNP], and N-terminal proBNP), ECG, and echocardiography. Monitoring occurred over 18 months for development of CVAEs.

RESULTS

Of 95 patients enrolled, 65 received carfilzomib and 30 received bortezomib, with median 25 months of follow-up. Sixty-four CVAEs occurred, with 55% grade 3 or greater in severity. CVAEs occurred in 51% of patients treated with carfilzomib and 17% of those treated with bortezomib (P = .002). Median time to first CVAE from treatment start was 31 days, and 86% occurred within the first 3 months. Patients receiving carfilzomib-based therapy with a baseline elevated BNP level higher than 100 pg/mL or N-terminal proBNP level higher than 125 pg/mL had increased risk for CVAE (odds ratio, 10.8; P < .001). Elevated natriuretic peptides occurring mid-first cycle of treatment with carfilzomib were associated with a substantially higher risk of CVAEs (odds ratio, 36.0; P < .001). Patients who experienced a CVAE had inferior progression-free survival (log-rank P = .01) and overall survival (log-rank P < .001). PI therapy was safely resumed in 89% of patients, although 41% required chemotherapy modifications.

CONCLUSION

CVAEs are common during PI therapy for relapsed MM, especially with carfilzomib, particularly within the first 3 months of therapy. CVAEs were associated with worse overall outcomes, but usually, discontinuation of therapy was not required. Natriuretic peptides were highly predictive of CVAEs; however, validation of this finding is necessary before uniform incorporation into the routine management of patients receiving carfilzomib.

Apixaban for Primary Prevention of Venous Thromboembolism in Patients With Multiple Myeloma Receiving Immunomodulatory Therapy

Immunomodulatory drugs (IMiDs), including thalidomide, lenalidomide, and pomalidomide, have improved survival of patients with multiple myeloma (MM). However, these therapies are associated with an increased risk of venous thromboembolism (VTE). Apixaban has been approved for treatment of acute VTE and for risk reduction of recurrent VTE following initial therapy. In this phase IV single-arm study (NCT02958969), we aim to prospectively evaluate the safety and efficacy of apixaban for primary prevention of VTE in patients with MM. The primary efficacy objective of this trial is to determine the rate of symptomatic VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE), over 6 months. The primary safety objective is to determine the rate of major bleeding in MM patients receiving apixaban prophylaxis. If proven safe and effective, apixaban will emerge as a promising option for oral VTE prophylaxis in MM patients.