Cardiovascular Toxicity of Proteasome Inhibitors: Underlying Mechanisms and Management Strategies: JACC: CardioOncology State-of-the-Art Review

Cardiovascular disease and cancer: shared risk factors and mechanisms

Cardiovascular disease (CVD) and cancer are among the leading causes of morbidity and mortality globally, and these conditions are increasingly recognized to be fundamentally interconnected. In this Review, we present the current epidemiological data for each of the modifiable risk factors shared by the two diseases, including hypertension, hyperlipidaemia, diabetes mellitus, obesity, smoking, diet, physical activity and the social determinants of health. We then review the epidemiological data demonstrating the increased risk of CVD in patients with cancer, as well as the increased risk of cancer in patients with CVD. We also discuss the shared mechanisms implicated in the development of these conditions, highlighting their inherent bidirectional relationship. We conclude with a perspective on future research directions for the field of cardio-oncology to advance the care of patients with CVD and cancer.

Ixazomib plus daratumumab and dexamethasone: Final analysis of a phase 2 study among patients with relapsed/refractory multiple myeloma

Novel therapies have improved outcomes for multiple myeloma (MM) patients, but most ultimately relapse, making treatment decisions for relapsed/refractory MM (RRMM) patients increasingly challenging. We report the final analysis of a single-arm, phase 2 study evaluating the oral proteasome inhibitor (PI) ixazomib combined with daratumumab and dexamethasone (IDd; NCT03439293). Sixty-one RRMM patients (ixazomib/daratumumab-naïve; 1-3 prior therapies) were enrolled to receive IDd (28-day cycles) until disease progression/unacceptable toxicity. Median age was 69 years; 14.8% of patients had International Staging System stage III disease; 14.8% had received three prior therapies. Patients received a median of 16 cycles of IDd. In 59 response-evaluable patients, the overall response rate was 64.4%; the confirmed ≥very good partial response (VGPR) rate (primary endpoint) was 30.5%. Rates of ≥VGPR in patient subgroups were: high-risk cytogenetics (n = 15, 26.7%), expanded high-risk cytogenetics (n = 24, 29.2%), aged ≥75 years (n = 12, 16.7%), lenalidomide-refractory (n = 21, 28.6%), and prior PI/IMiD therapy (n = 58, 31.0%). With a median follow-up of 31.6 months, median progression-free survival was 16.8 months (95% confidence interval: 10.1-23.7). Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 54.1% of patients; 44.3% had serious TEAEs; TEAEs led to dose modifications/reductions/discontinuations in 62.3%/36.1%/16.4%. There were five on-study deaths. Any-grade and grade ≥3 peripheral neuropathy occurred in 18.0% and 1.6% of patients. Quality of life was generally maintained throughout treatment. IDd showed a positive risk-benefit profile in RRMM patients and was active in clinically relevant subgroups with no new safety signals.

Intercellular pathways of cancer treatment-related cardiotoxicity and their therapeutic implications: the paradigm of radiotherapy

Advances in cancer therapeutics have improved patient survival rates. However, cancer survivors may suffer from adverse events either at the time of therapy or later in life. Cardiovascular diseases (CVD) represent a clinically important, but mechanistically understudied complication, which interfere with the continuation of best-possible care, induce life-threatening risks, and/or lead to long-term morbidity. These concerns are exacerbated by the fact that targeted therapies and immunotherapies are frequently combined with radiotherapy, which induces durable inflammatory and immunogenic responses, thereby providing a fertile ground for the development of CVDs. Stressed and dying irradiated cells produce 'danger' signals including, but not limited to, major histocompatibility complexes, cell-adhesion molecules, proinflammatory cytokines, and damage-associated molecular patterns. These factors activate intercellular signaling pathways which have potentially detrimental effects on the heart tissue homeostasis. Herein, we present the clinical crosstalk between cancer and heart diseases, describe how it is potentiated by cancer therapies, and highlight the multifactorial nature of the underlying mechanisms. We particularly focus on radiotherapy, as a case known to often induce cardiovascular complications even decades after treatment. We provide evidence that the secretome of irradiated tumors entails factors that exert systemic, remote effects on the cardiac tissue, potentially predisposing it to CVDs. We suggest how diverse disciplines can utilize pertinent state-of-the-art methods in feasible experimental workflows, to shed light on the molecular mechanisms of radiotherapy-related cardiotoxicity at the organismal level and untangle the desirable immunogenic properties of cancer therapies from their detrimental effects on heart tissue. Results of such highly collaborative efforts hold promise to be translated to next-generation regimens that maximize tumor control, minimize cardiovascular complications, and support quality of life in cancer survivors.

Endothelial injury and dysfunction with emerging immunotherapies in multiple myeloma, the impact of COVID-19, and endothelial protection with a focus on the evolving role of defibrotide

Patients with multiple myeloma (MM) were among the groups impacted more severely by the COVID-19 pandemic, with higher rates of severe disease and COVID-19-related mortality. MM and COVID-19, plus post-acute sequelae of SARS-CoV-2 infection, are associated with endothelial dysfunction and injury, with overlapping inflammatory pathways and coagulopathies. Existing treatment options for MM, notably high-dose therapy with autologous stem cell transplantation and novel chimeric antigen receptor (CAR) T-cell therapies and bispecific T-cell engaging antibodies, are also associated with endothelial cell injury and mechanism-related toxicities. These pathologies include cytokine release syndrome (CRS) and neurotoxicity that may be exacerbated by underlying endotheliopathies. In the context of these overlapping risks, prophylaxis and treatment approaches mitigating the inflammatory and pro-coagulant effects of endothelial injury are important considerations for patient management, including cytokine receptor antagonists, thromboprophylaxis with low-molecular-weight heparin and direct oral anticoagulants, and direct endothelial protection with defibrotide in the appropriate clinical settings.

Characteristics and outcomes of patients developing pulmonary hypertension associated with proteasome inhibitors

BACKGROUND

Pulmonary arterial hypertension (PAH) has been described in patients treated with proteasome inhibitors (PIs). Our objective was to evaluate the association between PIs and PAH.

METHODS

Characteristics of incident PAH cases previously treated with carfilzomib or bortezomib were analysed from the French pulmonary hypertension registry and the VIGIAPATH programme from 2004 to 2023, concurrently with a pharmacovigilance disproportionality analysis using the World Health Organization (WHO) global database (VigiBase) and a meta-analysis of randomised controlled trials.

RESULTS

11 incident cases of PI-associated PAH were identified (six with carfilzomib and five with bortezomib) with a female:male ratio of 2.7:1, a median age of 61 years, and a median delay between PI first exposure and PAH of 6 months. Four patients died (two from right heart failure, one from respiratory distress and one from an unknown cause). At diagnosis, six were in New York Heart Association Functional Class III/IV with severe haemodynamic impairment (median mean pulmonary arterial pressure 39 mmHg, cardiac index 2.45 L·min-1·m-2 and pulmonary vascular resistance 7.2 WU). In the WHO pharmacovigilance database, 169 cases of PH associated with PI were reported since 2013 with significant signals of disproportionate reporting (SDR) for carfilzomib, regardless of the definition of cases or control group. However, SDR for bortezomib were inconsistent. The systematic review identified 17 clinical trials, and carfilzomib was associated with a significantly higher risk of dyspnoea, severe dyspnoea and PH compared with bortezomib.

CONCLUSION

PIs may induce PAH in patients undergoing treatment, with carfilzomib emitting a stronger signal than bortezomib, and these patients should be monitored closely.

Thromboembolic risk of carfilzomib or bortezomib in combination with lenalidomide and dexamethasone for newly diagnosed multiple myeloma: A comparative systematic review and meta-analysis

Thrombosis represents a frequent and potentially severe complication in individuals diagnosed with multiple myeloma (MM). These events can be driven by both the disease as well as the therapies themselves. Overall, available evidence is inconclusive about the differential thrombogenicity of carfilzomib/lenalidomide/dexamethasone (KRd) and bortezomib/lenalidomide/dexamethasone (VRd). This meta-analysis compares the risk for venous thromboembolism (VTE; including deep venous thrombosis and pulmonary embolism) and arterial thromboembolism (ATE; including myocardial infarction and ischemic stroke) with KRd versus VRd as primary therapy for newly diagnosed MM (NDMM). Out of 510 studies identified after deduplication, one randomized controlled trial and five retrospective cohort studies were included. We analyzed 2304 patients (VRd: 1380; KRd: 924) for VTE events and 2179 patients (VRd: 1316; KRd: 863) for ATE events. Lower rates of VTE were observed in the VRd group when compared with the KRd group (6.16% vs. 8.87%; odds ratio [OR], 0.53; 95% confidence interval [CI], 0.32-0.88; p = .01). Both treatment groups exhibited minimal ATE incidence, with no significant difference between them (0.91% vs. 1.16%; OR, 1.01; 95% CI, 0.24-4.20; p = .99). In view of potential biases from retrospective studies, heterogeneity of baseline population characteristics, and limited access to patient-level data (e.g., VTE risk stratification and type of thromboprophylaxis regimen used) inherent to this meta-analysis, additional research is warranted to further validate our findings and refine strategies for thrombosis prevention in MM.

Non-coding RNAs and their potential exploitation in cancer therapy-related cardiotoxicity

Life expectancy in cancer patients has been extended in recent years, thanks to major breakthroughs in therapeutic developments. However, this also unmasked an increased incidence of cardiovascular diseases in cancer survivors, which is in part attributable to cancer therapy-related cardiovascular toxicity. Non-coding RNAs (ncRNAs) have received much appreciation due to their impact on gene expression. NcRNAs, which include microRNAs, long ncRNAs and circular RNAs, are non-protein-coding transcripts that are involved in the regulation of various biological processes, hence shaping cell identity and behaviour. They have also been implicated in disease development, including cardiovascular diseases, cancer and, more recently, cancer therapy-associated cardiotoxicity. This review outlines key features of cancer therapy-associated cardiotoxicity, what is known about the roles of ncRNAs in these processes and how ncRNAs could be exploited as therapeutic targets for cardioprotection.

Cancer Therapy-Associated Pulmonary Hypertension and Right Ventricular Dysfunction: Etiologies and Prognostic Implications

Advances in cancer therapies have improved oncologic outcomes but can potentially expose patients to risk of cardiovascular toxicity. While left ventricular (LV) dysfunction is a well-known cardiotoxicity of cancer therapy. Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are seen with several cancer therapies, including alkylating agents, tyrosine kinase inhibitors (TKIs), and immunotherapy, and are associated with significant morbidity and mortality. Awareness and recognition of cancer therapy-associated PH and RV dysfunction is critical to identify underlying etiologies and institute the appropriate therapy. However, gaps exist in the current literature on the epidemiology of PH and RV dysfunction in cancer, underlying pathophysiology and optimal management strategies.

Cyclophosphamide, Bortezomib, and Dexamethasone and Severe Systolic Heart Failure: A Case Report

Multiple myeloma (MM) is a neoplastic proliferation of plasma cells in bone marrow. Pharmacotherapy for the management of patients with MM includes drug classes like proteasome inhibitors, monoclonal antibodies, immunomodulators, alkylating agents, steroids, etc. We present a case of new-onset heart failure with reduced ejection fraction (HFrEF) in a patient with previously normal ejection fraction after treatment with a cyclophosphamide, bortezomib, and dexamethasone (CyBorD) chemotherapeutic regimen. An echocardiogram done after the completion of nine cycles of chemotherapy in a period of about 4.5 months showed severely decreased left ventricular systolic function with an ejection fraction of only 15-20% and grade I diastolic dysfunction. Cardiac catheterization showed no angiographic evidence of vessel occlusion or epicardial disease. HFrEF was managed with the initiation of guideline-directed medical therapy with cardiology clinic follow-up, and the patient was discharged with a plan to start a lenalidomide-based chemotherapeutic regimen with oncology clinic follow-up. It is, therefore, imperative to perform a thorough cardiovascular assessment before initiation of chemotherapy, complemented by periodic and recurrent assessments of cardiovascular function during and after completion of the treatment course, for early detection and prevention of potentially severe cardiovascular toxicities in patients with MM.

Real-world incidence and risk factors of bortezomib-related cardiovascular adverse events in patients with multiple myeloma

BACKGROUND

Although most studies on the cardiovascular toxicity of proteasome inhibitors have focused on carfilzomib, the risk of cardiotoxicity associated with bortezomib remains controversial. This study aimed to evaluate the incidence and risk factors of cardiovascular adverse events (CVAEs) associated with bortezomib in patients with multiple myeloma in a real-world setting.

METHODS

This cross-sectional study included patients who were treated with bortezomib at a tertiary hospital in South Korea. CVAEs, defined as hypertension, arrhythmia, heart failure, myocardial infarction, pulmonary arterial hypertension, angina, and venous thromboembolism, were detected using cardiac markers, ECG, echocardiography, medications, or documentation by clinicians. The patients were observed for at least 6 months and up to 2 years after starting bortezomib administration.

RESULTS

Among the 395 patients, 20.8% experienced CVAEs of any grade, and 14.7% experienced severe adverse events. The median onset time for any CVAE was 101.5 days (IQR, 42-182 days), and new-onset/worsened hypertension was the most prevalent CVAE. The risk of CVAEs increased in patients with a body mass index lower than 18.5 (adjusted HR (aHR) 3.50, 95% confidence interval (CI) 1.05-11.72), light chain (1.80, 1.04-3.13), and IgD (4.63, 1.06-20.20) as the multiple myeloma subtype, baseline stroke (4.52, 1.59-12.80), and hypertension (1.99, 1.23-3.23). However, CVAEs did not significantly affect the 2-year overall survival and progression-free survival.

CONCLUSION

Approximately 15% of the Korean patients treated with bortezomib experienced severe CVAEs. Thus, patients, especially those with identified risk factors, should be closely monitored for CVAE symptoms during bortezomib treatment.

Repurposing proteasome inhibitors for improved treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is associated with poor prognosis and limited treatment options due to the lack of important receptors (estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor 2 [HER2]) used for targeted therapy. However, high-throughput in vitro drug screening of cell lines is a powerful tool for identifying effective drugs for a disease. Here, we determine the intrinsic chemosensitivity of TNBC cell lines to proteasome inhibitors (PIs), thereby identifying potentially potent 2-drug combinations for TNBC. Eight TNBC cell lines (BT-549, CAL-148, HCC1806, HCC38, HCC70, MDA-MB-436, MDA-MB-453, and MDA-MB-468) and two controls (MCF-10A and MCF-7) were first exposed to 18 drugs (11 PIs and 7 clinically relevant chemotherapeutic agents) as monotherapy, followed by prediction of potent 2-drug combinations using the IDACombo pipeline. The synergistic effects of the 2-drug combinations were evaluated with SynergyFinder in four TNBC cell lines (CAL-148, HCC1806, HCC38, and MDA-MB-468) and three controls (BT-474, MCF-7, and T47D) in vitro, followed by further evaluation of tumor regression in zebrafish tumor models established using HCC1806 and MCF-7 cells. Monotherapy identified nine effective drugs (bortezomib, carfilzomib, cisplatin, delanzomib, docetaxel, epoxomicin, MLN-2238, MLN-9708, and nedaplatin) across all cell lines. PIs (e.g., bortezomib, delanzomib, and epoxomicin) were highly potent drugs in TNBC cells, of which bortezomib and delanzomib inhibited the chymotrypsin-like activity of the 20 S proteasome by 100% at 10 µM. Moreover, several potent 2-drug combinations (e.g., bortezomib+nedaplatin and epoxomicin+epirubicin) that killed virtually 100% of cells were also identified. Although HCC1806- and MCF-7-derived xenografts treated with bortezomib+nedaplatin and carboplatin+paclitaxel were smaller, HCC1806 cells frequently metastasized to the trunk region. Taken together, we show that PIs used in combination with platinum agents or topoisomerase inhibitors exhibit increased efficiency with almost 100% inhibition in TNBC cell lines, indicating that PIs are therefore promising compounds to use as combination therapy for TNBC.

Management of hypertension in patients with cancer: challenges and considerations

The survival rates of many cancers have significantly improved due to recent advancements in cancer screening and therapeutics. Although better cancer outcomes are encouraging, additional health challenges have surfaced, the utmost of which is the burden imposed by various cardiovascular and renal toxicities of anticancer therapies. To improve the overall outcome of patients with cancer, it is essential to understand and manage these treatment-related adverse effects. The cardiovascular side effects of antineoplastic therapies are well-known and include left ventricular dysfunction, heart failure, myocardial ischaemia, QT prolongation, arrhythmia and hypertension. Among these, hypertension is the most common complication, prevalent in about 40% of all cancer patients, yet frequently overlooked and undertreated. This review explores the intricate connection between cancer and hypertension and provides distinct approaches to diagnosing, monitoring and managing hypertension in patients with cancer. We also outline the challenges and considerations that are relevant to the care of patients receiving anticancer drugs with prohypertensive potential.

Overcoming proteasome inhibitor resistance in the immunotherapy era

Proteasome inhibitors (PIs) are a fascinating class of small molecules that disrupt protein homeostasis and are highly efficacious in the blood cancer multiple myeloma. However, PIs are not curative, and overcoming PI resistance to extend patient survival remains a major unmet need. Recent strategies to overcome PI resistance, including inhibiting alternative protein homeostasis pathways and targeting the mitochondrion as a nexus of metabolic adaptation to PIs, are gaining momentum. However, these focused approaches may be surpassed or even obviated by quickly emerging immunotherapy strategies that do not selectively target PI resistance mechanisms but are highly efficacious in PI-resistant disease, nonetheless. Informed by insights from these promising areas of research moving in parallel, we propose that pharmacological strategies to enforce immunotherapeutic vulnerabilities in resistant disease may provide a unified outlook to overcome PI resistance in a 'new era' of myeloma treatment.

The double-hit protocol induces HFpEF and impairs myocardial ubiquitin-proteasome system performance in FVB/N mice

Heart failure with preserved ejection fraction (HFpEF) is a leading cause of death and disability, with its prevalence surpassing that of heart failure with reduced ejection fraction. Obesity and hypertension are often associated with HFpEF. HFpEF can be modeled through simultaneous metabolic and hypertensive stresses in male C57BL/6N mice provoked by a combination treatment of a high-fat diet (HFD) and constitutive nitric oxide synthase inhibition by Nω-nitro-L-arginine methyl-ester (L-NAME). Ubiquitin-proteasome system (UPS) dysfunction was detected in many forms of cardiomyopathy, but whether it occurs in HFpEF remains unknown. We report successful modeling of HFpEF in male FVB/N mice and, by taking advantage of a transgenic UPS reporter mouse, we have detected myocardial UPS functioning impairment during HFpEF, suggesting a pathogenic role for impaired protein degradation in the development and progression of HFpEF.