Cardiovascular Effects of the MEK Inhibitor, Trametinib: A Case Report, Literature Review, and Consideration of Mechanism

Risk Stratification, Screening and Treatment of BRAF/MEK Inhibitors-Associated Cardiotoxicity

PURPOSE OF REVIEW

In this review article we describe the cardiovascular adverse events associated with BRAF and MEK inhibitors as well as their pathophysiologic mechanisms and provide up to date guidance for risk stratified surveillance of patients on treatment and the optimal management of emergent cardiotoxicities.

RECENT FINDINGS

Combination BRAF/MEK inhibition has become an established standard treatment option for patients with a wide variety of BRAF mutant haematological and solid organ cancers, its use is most commonly associated with stage three and metastatic melanoma. The introduction of these targeted drugs has significantly improved the prognosis of previously treatment resistant cancers. It is increasingly recognised that these drugs have a number of cardiovascular toxicities including left ventricular systolic dysfunction, hypertension and QTc interval prolongation. Whilst cardiotoxicity is largely reversible and manageable with medical therapy, it does limit the effective use of these highly active agents.

Is Autophagy Targeting a Valid Adjuvant Strategy in Conjunction with Tyrosine Kinase Inhibitors?

Tyrosine kinase inhibitors (TKIs) represent a relatively large class of small-molecule inhibitors that compete with ATP for the catalytic binding site of tyrosine kinase proteins. While TKIs have demonstrated effectiveness in the treatment of multiple malignancies, including chronic myelogenous leukemia, gastrointestinal tumors, non-small cell lung cancers, and HER2-overexpressing breast cancers, as is almost always the case with anti-neoplastic agents, the development of resistance often imposes a limit on drug efficacy. One common survival response utilized by tumor cells to ensure their survival in response to different stressors, including anti-neoplastic drugs, is that of autophagy. The autophagic machinery in response to TKIs in multiple tumor models has largely been shown to be cytoprotective in nature, although there are a number of cases where autophagy has demonstrated a cytotoxic function. In this review, we provide an overview of the literature examining the role that autophagy plays in response to TKIs in different preclinical tumor model systems in an effort to determine whether autophagy suppression or modulation could be an effective adjuvant strategy to increase efficiency and/or overcome resistance to TKIs.

Navigating cancer therapy induced cardiotoxicity: From pathophysiology to treatment innovations

Every year, more than a million people in the United States undergo chemotherapy or radiation therapy for cancer, as estimated by the CDC. While chemotherapy has been an instrumental tool for treating cancer, it also causes severe adverse effects. The more commonly acknowledged adverse effects include hair loss, fatigue, and nausea, but a more severe and longer lasting side effect is cardiotoxicity. Cardiotoxicity, or heart damage, is a common complication of cancer treatments. It can range from mild to severe, and it can affect some patients temporarily or others permanently, even after they are cured of cancer. Dexrazoxane is the only FDA-approved drug for treating anthracycline induced cardiotoxicity, but it also has drawbacks and adverse effects. There is no other type of chemotherapy induced cardiotoxicity that has an approved treatment option. In this review, we discuss the pathophysiology of chemotherapeutic-induced cardiotoxicity, methods and guidelines of diagnosis, methods of treatment and mitigation, and current drug delivery approaches in therapeutic development.

Progress in the development of ERK1/2 inhibitors for treating cancer and other diseases

The extracellular signal-regulated kinases-1 and 2 (ERK1/2) are ubiquitous regulators of many cellular functions, including proliferation, differentiation, migration, and cell death. ERK1/2 regulate cell functions by phosphorylating a diverse collection of protein substrates consisting of other kinases, transcription factors, structural proteins, and other regulatory proteins. ERK1/2 regulation of cell functions is tightly regulated through the balance between activating phosphorylation by upstream kinases and inactivating dephosphorylation by phosphatases. Disruption of homeostatic ERK1/2 regulation caused by elevated extracellular signals or mutations in upstream regulatory proteins leads to the constitutive activation of ERK1/2 signaling and uncontrolled cell proliferation observed in many types of cancer. Many inhibitors of upstream kinase regulators of ERK1/2 have been developed and are part of targeted therapeutic options to treat a variety of cancers. However, the efficacy of these drugs in providing sustained patient responses is limited by the development of acquired resistance often involving re-activation of ERK1/2. As such, recent drug discovery efforts have focused on the direct targeting of ERK1/2. Several ATP competitive ERK1/2 inhibitors have been identified and are being tested in cancer clinical trials. One drug, Ulixertinib (BVD-523), has received FDA approval for use in the Expanded Access Program for patients with no other therapeutic options. This review provides an update on ERK1/2 inhibitors in clinical trials, their successes and limitations, and new academic drug discovery efforts to modulate ERK1/2 signaling for treating cancer and other diseases.

Real-world data of cardio-oncologic interventions for cardiovascular adverse events with oral oncolytics

BACKGROUND

Oral cancer therapy-related cardiovascular (CV) toxicity has a wide variety of presentations including arrhythmia, cardiomyopathy, and myocardial infarction, but clinical evidence related to its management is limited. The purpose of this IRB-approved, single-center, retrospective, cohort study was to characterize cardio-oncologic interventions for CV adverse events related to oral oncolytics.

METHODS

The cohort included 67 patients who were admitted to a multi-hospital health system between June 1, 2016 and July 31, 2021, had at least one medical record order of oral oncolytics considered to have cardiotoxic potential, and had an ICD10 code for a cardiotoxic event added to their electronic medical records after initiation of oral oncolytics.

RESULTS

The majority (97%) had pre-existing cardiovascular disease (CVD) or a CV risk factor. The three most common classes of oral oncolytics were aromatase inhibitors (36%), BCR-ABL inhibitors (16%), and VEGFR inhibitors (13%). New-onset or worsening heart failure (HF) (n = 31), which occurred after a median of 148 days (Interquartile range (IQR) 43-476 days) was the most common cardiotoxic event. The most frequent interventions were pharmacological treatment of the CV adverse event (n = 44) and treatment interruption (n = 18), but guideline-directed medication therapy for HF could be further optimized.

CONCLUSION

Pre-existing CVD or CV risk factors predispose oncology patients to CV adverse events. Real-world practice reveals that CV adverse events require temporary interruption of treatment and initiation of pharmacologic treatment. A multidisciplinary, patient-centered approach that includes discussion of risks/benefits of treatment continuation, and initiation of guideline-directed treatment is recommended until high-quality, drug-specific data for monitoring and treatment become available.

Novel insights into cardiovascular toxicity of cancer targeted and immune therapies: Beyond ischemia with non-obstructive coronary arteries (INOCA)

Novel immune and targeted therapies approved over the past 2 decades have resulted in dramatic improvements in cancer-specific outcomes for many cancer patients. However, many of these agents can induce cardiovascular toxicity in a subset of patients. The field of cardio-oncology was established based on observations that anti-neoplastic chemotherapies and mantle radiation can lead to premature cardiomyopathy in cancer survivors. While conventional chemotherapy, targeted therapy, and immune therapies can all result in cardiovascular adverse events, the mechanisms, timing, and incidence of these events are inherently different. Many of these effects converge upon the coronary microvasculature to involve, through endocardial endothelial cells, a more direct effect through close proximity to cardiomyocyte with cellular communication and signaling pathways. In this review, we will provide an overview of emerging paradigms in the field of Cardio-Oncology, particularly the role of the coronary microvasculature in mediating cardiovascular toxicity of important cancer targeted and immune therapies. As the number of cancer patients treated with novel immune and targeted therapies grows exponentially and subsequently the number of long-term cancer survivors dramatically increases, it is critical that cardiologists and cardiology researchers recognize the unique potential cardiovascular toxicities of these agents.

Trametinib ameliorates aging-associated gut pathology in Drosophila females by reducing Pol III activity in intestinal stem cells

Pharmacological therapies are promising interventions to slow down aging and reduce multimorbidity in the elderly. Studies in animal models are the first step toward translation of candidate molecules into human therapies, as they aim to elucidate the molecular pathways, cellular mechanisms, and tissue pathologies involved in the anti-aging effects. Trametinib, an allosteric inhibitor of MEK within the Ras/MAPK (Ras/Mitogen-Activated Protein Kinase) pathway and currently used as an anti-cancer treatment, emerged as a geroprotector candidate because it extended lifespan in the fruit fly Drosophila melanogaster. Here, we confirm that trametinib consistently and robustly extends female lifespan, and reduces intestinal stem cell (ISC) proliferation, tumor formation, tissue dysplasia, and barrier disruption in guts in aged flies. In contrast, pro-longevity effects of trametinib are weak and inconsistent in males, and it does not influence gut homeostasis. Inhibition of the Ras/MAPK pathway specifically in ISCs is sufficient to partially recapitulate the effects of trametinib. Moreover, in ISCs, trametinib decreases the activity of the RNA polymerase III (Pol III), a conserved enzyme synthesizing transfer RNAs and other short, non-coding RNAs, and whose inhibition also extends lifespan and reduces gut pathology. Finally, we show that the pro-longevity effect of trametinib in ISCs is partially mediated by Maf1, a repressor of Pol III, suggesting a life-limiting Ras/MAPK-Maf1-Pol III axis in these cells. The mechanism of action described in this work paves the way for further studies on the anti-aging effects of trametinib in mammals and shows its potential for clinical application in humans.

CDK4/6 inhibitors: basics, pros, and major cons in breast cancer treatment with specific regard to cardiotoxicity - a narrative review

Breast cancer is characterized by the uncontrolled proliferation of breast cells, with a high incidence reported in 2020 to have affected over 2 million women. In recent years, the conventional methods of treating breast cancer have involved radiotherapy and chemotherapy. However, the emergence of CDK4/6 inhibitors has shown potential as a promising cancer therapy. Cyclin-dependent kinases (CDK) inhibitors are a class of molecules that impede the formation of an active kinase complex, thereby hindering its activity and consequently halting the progression of the cell cycle. It was discovered that they have a significant impact on impeding the progression of the cancer. This is evident with the Food and Drug Administration's approval of drugs such as palbociclib, ribociclib, and abemaciclib for hormone receptor-positive metastatic breast cancer in combination with specific endocrine therapies. In spite of enormous success in breast cancer treatment, certain obstacles have emerged, such as therapy resistance, side effects, and most of all, cardiotoxicity. Some of these drawbacks have been successfully overcome by dosage reduction, different combinations of the drugs, and the assessment of each patient's condition and suitability prior to treatment. Yet other drawbacks still require tenacious research, especially certain cases of cardiotoxicities. This article delves into the biological mechanisms of CDK4/6 in the cell cycle and cancer, as well as the clinical advantages and most common adverse events (AEs) associated with CDK4/6 inhibitors. The primary objective of this review is to provide a comprehensive analysis of cardiotoxic AEs and elucidate the underlying pathophysiological mechanisms responsible for the cardiotoxicity of CDK4/6 inhibitors.

Long-term safety and efficacy of selumetinib in children with neurofibromatosis type 1 on a phase 1/2 trial for inoperable plexiform neurofibromas

BACKGROUND

Selumetinib shrank inoperable symptomatic plexiform neurofibromas (PN) in children with neurofibromatosis type 1 (NF1) and provided clinical benefit for many in our previously published phase 1/2 clinical trials (SPRINT, NCT01362803). At the data cutoff (DCO) of the prior publications, 65% of participants were still receiving treatment. This report presents up to 5 years of additional safety and efficacy data from these studies.

METHODS

This manuscript includes data from the phase 1 and phase 2, stratum 1 study which included participants with clinically significant PN-related morbidity. Participants received continuous selumetinib dosing (1 cycle = 28 days). Safety and efficacy data through February 27, 2021 are included. PN response assessed by volumetric magnetic resonance imaging analysis: Confirmed partial response (cPR) ≥20% decrease from baseline on 2 consecutive evaluations. Phase 2 participants completed patient-reported outcome measures assessing tumor pain intensity (Numeric Rating Scale-11) and interference of pain in daily life (pain interference index).

RESULTS

For the 74 children (median age 10.3 years; range 3-18.5) enrolled, overall cPR rate was 70% (52/74); median duration of treatment was 57.5 cycles (range 1-100). Responses were generally sustained with 59% (44) lasting ≥ 12 cycles. Tumor pain intensity (n = 19, P = .015) and pain interference (n = 18, P = .0059) showed durable improvement from baseline to 48 cycles. No new safety signals were identified; however, some developed known selumetinib-related adverse events (AEs) for the first time after several years of treatment.

CONCLUSIONS

With up to 5 years of additional selumetinib treatment, most children with NF1-related PN had durable tumor shrinkage and sustained improvement in pain beyond that previously reported at 1 year. No new safety signals were identified; however, ongoing monitoring for known selumetinib-related AEs is needed while treatment continues.

The Impact of Drug-Drug Interactions on the Toxicity Profile of Combined Treatment with BRAF and MEK Inhibitors in Patients with BRAF-Mutated Metastatic Melanoma

BACKGROUND

BRAF and MEK inhibition is a successful strategy in managing BRAF-mutant melanoma, even if the treatment-related toxicity is substantial. We analyzed the role of drug-drug interactions (DDI) on the toxicity profile of anti-BRAF/anti-MEK therapy.

METHODS

In this multicenter, observational, and retrospective study, DDIs were assessed using Drug-PIN software (V 2/23). The association between the Drug-PIN continuous score or the Drug-PIN traffic light and the occurrence of treatment-related toxicities and oncological outcomes was evaluated.

RESULTS

In total, 177 patients with advanced BRAF-mutated melanoma undergoing BRAF/MEK targeted therapy were included. All grade toxicity was registered in 79% of patients. Cardiovascular toxicities occurred in 31 patients (17.5%). Further, 94 (55.9%) patients had comorbidities requiring specific pharmacological treatments. The median Drug-PIN score significantly increased when the target combination was added to the patient's home therapy (p-value < 0.0001). Cardiovascular toxicity was significantly associated with the Drug-PIN score (p-value = 0.048). The Drug-PIN traffic light (p = 0.00821) and the Drug-PIN score (p = 0.0291) were seen to be significant predictors of cardiotoxicity. Patients with low-grade vs. high-grade interactions showed a better prognosis regarding overall survival (OS) (p = 0.0045) and progression-free survival (PFS) (p = 0.012). The survival analysis of the subgroup of patients with cardiological toxicity demonstrated that patients with low-grade vs. high-grade DDIs had better outcomes in terms of OS (p = 0.0012) and a trend toward significance in PFS (p = 0.068).

CONCLUSIONS

DDIs emerged as a critical issue for the risk of treatment-related cardiovascular toxicity. Our findings support the utility of DDI assessment in melanoma patients treated with BRAF/MEK inhibitors.

Potential drug-drug interactions with mitogen-activated protein kinase (MEK) inhibitors used to treat melanoma

INTRODUCTION

The management of patients with BRAF-mutated advanced melanoma who are undergoing targeted therapy with MEK inhibitors can be complicated by the co-administration of multiple medications, which can give rise to drug-drug interactions of clinical significance.

COVERED AREAS

Our review presents a comprehensive analysis of the pharmacokinetic and pharmacodynamic interactions of the three approved for advanced melanoma MEK inhibitor drugs - binimetinib, cobimetinib, and trametinib. MEDLINE (PubMed) was utilized for the literature search, comprising clinical studies, observational studies, and preclinical research. The review discusses the impact of these interactions on efficacy and safety of the treatments and differentiates between interactions supported by pharmacokinetic or pharmacodynamic mechanisms, those encountered in clinical practice, and those observed in preclinical studies.

EXPERT OPINION

Physicians should be aware about potential benefits, but also increased toxicity caused by drug interactions between MEK inhibitors and other drugs in the management of patients with metastatic melanoma.

Established and Emerging Cancer Therapies and Cardiovascular System: Focus on Hypertension-Mechanisms and Mitigation

Cardiovascular disease and cancer are 2 of the leading causes of death worldwide. Although improvements in outcomes have been noted for both disease entities, the success of cancer therapies has come at the cost of at times very impactful adverse events such as cardiovascular events. Hypertension has been noted as both, a side effect as well as a risk factor for the cardiotoxicity of cancer therapies. Some of these dynamics are in keeping with the role of hypertension as a cardiovascular risk factor not only for heart failure, but also for the development of coronary and cerebrovascular disease, and kidney disease and its association with a higher morbidity and mortality overall. Other aspects such as the molecular mechanisms underlying the amplification of acute and long-term cardiotoxicity risk of anthracyclines and increase in blood pressure with various cancer therapeutics remain to be elucidated. In this review, we cover the latest clinical data regarding the risk of hypertension across a spectrum of novel anticancer therapies as well as the underlying known or postulated pathophysiological mechanisms. Furthermore, we review the acute and long-term implications for the amplification of the development of cardiotoxicity with drugs not commonly associated with hypertension such as anthracyclines. An outline of management strategies, including pharmacological and lifestyle interventions as well as models of care aimed to facilitate early detection and more timely management of hypertension in patients with cancer and survivors concludes this review, which overall aims to improve both cardiovascular and cancer-specific outcomes.

Discovery of Coumarin-Based MEK1/2 PROTAC Effective in Human Cancer Cells

The RAF/MEK/ERK pathway is a crucial signal path which is closely associated with the proliferation, differentiation, and apoptosis of tumors. MEK1/2 is a key kinase target in the pathway, with ERK1/2 acting as the main substrate of it. Despite the rapid development of MEK1/2 inhibitors, acquired resistance still happens and remains a significant problem. Most of the inhibitors possess a similar diarylamine scaffold. Here we designed and synthesized a series of MEK1/2 degraders based on a coumarin derivative which was a potent non-diarylamine allosteric MEK1/2 inhibitor. P6b among them showed the most potent degradation effect, with DC50 values of 0.3 μM and 0.2 μM in MEK1 and MEK2 degradation, respectively. An antiproliferation assay showed that it more significantly inhibits the growth of A375 cells (IC50= 2.8 μM) compared to A549 cells (IC50 = 27.3 μM). To sum up, we discovered P6b with a non-diarylamine scaffold for the first time as a potent MEK PROTAC effective in human cancer cells.

Implications of BRAF V600E mutation in gliomas: Molecular considerations, prognostic value and treatment evolution

Gliomas are molecularly heterogeneous brain tumors responsible for the most years of life lost by any cancer. High-grade gliomas have a poor prognosis and despite multimodal treatment including surgery, radiotherapy, and chemotherapy, exhibit a high recurrence rate. There is a need for new therapeutic approaches based on precision medicine informed by biomarker assessment and BRAF, a key regulator of MAPK signaling pathway, influencing cell differentiation, proliferation, migration and pro-tumorigenic activity, is emerging as a promising molecular target. V600E, is the most frequent BRAF alteration in gliomas, especially in pediatric low-grade astrocytomas, pleomorphic xanthoastrocytoma, papillary craniopharyngioma, epithelioid glioblastoma and ganglioglioma. The possible application of BRAF-targeted therapy in gliomas is continuously growing and there is preliminary evidence of prolonged disease control obtained by BRAF inhibitors in tumors harboring BRAF V600E mutation. The possibility of introducing targeted therapies into the treatment algorithm represents a paradigm shift for patients with BRAF V600E mutant recurrent high-grade and low-grade glioma and BRAF routine testing should be considered in clinical practice. The focus of this review is to summarize the molecular landscape of BRAF across glioma subtypes and the novel therapeutic strategies for BRAF V600E mutated tumors.

A non-coding GWAS variant impacts anthracycline-induced cardiotoxic phenotypes in human iPSC-derived cardiomyocytes

Anthracyclines, widely used to treat breast cancer, have the potential for cardiotoxicity. We have previously identified and validated a germline single nucleotide polymorphism, rs28714259, associated with an increased risk of anthracycline-induced heart failure. We now provide insights into the mechanism by which rs28714259 might confer increased risk of cardiac damage. Using hiPSC-derived cardiomyocyte cell lines with either intrinsic polymorphism or CRISPR-Cas9-mediated deletion of rs28714259 locus, we demonstrate that glucocorticoid receptor signaling activated by dexamethasone pretreatment prior to doxorubicin exposure preserves cardiomyocyte viability and contractility in cardiomyocytes containing the major allele. Homozygous loss of the rs28714259 major allele diminishes dexamethasone's protective effect. We further demonstrate that the risk allele of rs28714259 disrupts glucocorticoid receptor and rs28714259 binding affinity. Finally, we highlight the activation of genes and pathways involved in cardiac hypertrophy signaling that are blocked by the risk allele, suggesting a decreased adaptive survival response to doxorubicin-related stress.

Cellular and Molecular Mechanisms of MEK1 Inhibitor-Induced Cardiotoxicity

Background

Trametinib is a MEK1 (mitogen-activated extracellular signal-related kinase kinase 1) inhibitor used in the treatment of BRAF (rapid accelerated fibrosarcoma B-type)-mutated metastatic melanoma. Roughly 11% of patients develop cardiomyopathy following long-term trametinib exposure. Although described clinically, the molecular landscape of trametinib cardiotoxicity has not been characterized.

Objectives

The aim of this study was to test the hypothesis that trametinib promotes widespread transcriptomic and cellular changes consistent with oxidative stress and impairs cardiac function.

Methods

Mice were treated with trametinib (1 mg/kg/d). Echocardiography was performed pre- and post-treatment. Gross, histopathologic, and biochemical assessments were performed to probe for molecular and cellular changes. Human cardiac organoids were used as an in vitro measurement of cardiotoxicity and recovery.

Results

Long-term administration of trametinib was associated with significant reductions in survival and left ventricular ejection fraction. Histologic analyses of the heart revealed myocardial vacuolization and calcification in 28% of animals. Bulk RNA sequencing identified 435 differentially expressed genes and 116 differential signaling pathways following trametinib treatment. Upstream gene analysis predicted interleukin-6 as a regulator of 17 relevant differentially expressed genes, suggestive of PI3K/AKT and JAK/STAT activation, which was subsequently validated. Trametinib hearts displayed elevated markers of oxidative stress, myofibrillar degeneration, an 11-fold down-regulation of the apelin receptor, and connexin-43 mislocalization. To confirm the direct cardiotoxic effects of trametinib, human cardiac organoids were treated for 6 days, followed by a 6-day media-only recovery. Trametinib-treated organoids exhibited reductions in diameter and contractility, followed by partial recovery with removal of treatment.

Conclusions

These data describe pathologic changes observed in trametinib cardiotoxicity, supporting the exploration of drug holidays and alternative pharmacologic strategies for disease prevention.

Mechanisms shared between cancer, heart failure, and targeted anti-cancer therapies

Heart failure (HF) and cancer are the leading causes of death worldwide and accumulating evidence demonstrates that HF and cancer affect one another in a bidirectional way. Patients with HF are at increased risk for developing cancer, and HF is associated with accelerated tumour growth. The presence of malignancy may induce systemic metabolic, inflammatory, and microbial alterations resulting in impaired cardiac function. In addition to pathophysiologic mechanisms that are shared between cancer and HF, overlaps also exist between pathways required for normal cardiac physiology and for tumour growth. Therefore, these overlaps may also explain the increased risk for cardiotoxicity and HF as a result of targeted anti-cancer therapies. This review provides an overview of mechanisms involved in the bidirectional connection between HF and cancer, specifically focusing upon current 'hot-topics' in these shared mechanisms. It subsequently describes targeted anti-cancer therapies with cardiotoxic potential as a result of overlap between their anti-cancer targets and pathways required for normal cardiac function.

Triple MAPK inhibition salvaged a relapsed post-BCMA CAR-T cell therapy multiple myeloma patient with a BRAF V600E subclonal mutation

Background

Multiple Myeloma (MM) is a progressive plasma cell neoplasm characterized by heterogeneous clonal expansion. Despite promising response rates achieved with anti-BCMA CAR-T cell therapy, patients may still relapse and there are currently no clear therapeutic options in post-CAR-T settings. In this report, we present a case of a post-BCMA CAR-T relapsed/refractory (RR) MM patient with skin extramedullary disease (EMD) in which a novel MAPK inhibition combinatorial strategy was implemented based on next-generation sequencing and in vitro experiments.

Case presentation

A 61-year-old male with penta-refractory MM penta- (IgA lambda), ISS stage 3 with hyperdiploidy, gain of 1q21 and del13 was treated with anti-BCMA CAR-T cell therapy, achieving a best response of VGPR. He progressed after 6 months and was salvaged for a short period with autologous stem cell transplantation. Eventually, he progressed with extramedullary disease manifested as subcutaneous nodules. Based on whole-exome sequencing, we identified a BRAF (V600E) dominant subclone in both bone marrow and cutaneous plasmacytoma. Following in vitro experiments, and according to our previous studies, we implemented a triple MAPK inhibition strategy under which the patient achieved a very good partial response for 110 days, which allowed to bridge him to subsequent clinical trials and eventually achieve a stringent complete response (sCR).

Conclusion

Here, we show the applicability, effectiveness, and tolerability the triple MAPK inhibition strategy in the context of post-BCMA CAR-T failure in specific subset of patients. The triple therapy could bridge our hospice bound RRMM patient with BRAF (V600E) to further therapeutic options where sCR was achieved. We will further evaluate triple MAPK inhibition in patients with BRAF V600E in a precision medicine clinical trial launching soon.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-022-01330-3.

Cardiac Function in Children and Young Adults Treated with MEK Inhibitors: A Retrospective Cohort Study

MEK inhibitors (MEKi) have shown efficacy in pediatric low-grade glioma as well as plexiform neurofibroma. MEKi have been associated with acute cardiac dysfunction in adults. Cardiac consequences in children are unknown. We performed a single center retrospective cohort study evaluating cardiac function by echocardiography (echo) in children and young adults < 21 years receiving MEKi between October 2013 and May 2018. Blinded assessment of left ventricular function by fractional shortening (FS) and ejection fraction (EF) was performed on all available echocardiograms performed before, during, and following therapy, as well as after re-initiation of therapy. Twenty-six patients underwent MEKi therapy with echo follow-up during the study period. Twenty-four of these had complete echo data. Median follow-up was 12 months. Borderline EF (EF 53-57.9%) occurred in 12 (50%) patients; and 3 (12.5%) progressed to abnormal EF (EF < 53%). Cardiac dysfunction, when it occurred, was mild (lowest documented EF was 45%, and lowest FS was 24.4%). EF abnormalities typically fluctuated during therapy, resolved off therapy, and recurred with MEKi re-initiation. No clinical or demographic differences were detected between those who maintained normal cardiac function and those who developed borderline or overt cardiac dysfunction. Symptomatic heart failure did not occur. In this cohort of children and young adults, MEKi use was associated with a high (50%) incidence of borderline or mildly decreased left ventricular function. There was no evidence of permanent cardiac dysfunction. Further evaluation in larger prospective trials is needed.

Cardiovascular disease and malignant melanoma

In the last decade, systemic therapies such as immune checkpoint inhibitors and BRAF-MEK inhibitors have improved the prognosis of high-risk and advanced melanoma. With improved survival, melanoma survivorship is increasingly important, particularly in patients who have a good prognosis or are diagnosed at a younger age. It is increasingly recognized that cancer and its treatment is associated with increased cardiovascular morbidity and mortality. Indeed, data from observational studies and meta-analyses of randomized controls trials in melanoma show that systemic therapies may be associated with cardiac toxicities, such as myocardial infarction, heart failure, myocarditis and stroke. Our review will discuss cardiovascular disease and risk factors in the context of melanoma and outline the importance of cardiovascular risk modification in this population.

Cancer Therapies and Vascular Toxicities

OPINION STATEMENT

Vascular events have become an important issue in the overall management of cancer patients. They usually result from a combination of (i) direct or indirect toxicity of anticancer treatments, (ii) a higher prevalence of cardiovascular risk factors in cancer patients, and (iii) prolonged exposure to treatments due to an increasing patient survival rate. In addition to conventional chemotherapies and radiotherapy, targeted therapies and immunotherapies have been developed which improve the prognosis of cancer patients but sometimes at the cost of vascular toxicity, which can lead to systemic or pulmonary hypertension and arterial/venous thromboembolic events. Endothelial dysfunction, a procoagulant state and metabolic disorders are the three main pathophysiological patterns leading to cancer treatment-related vascular toxicity. This issue is challenging because serious vascular adverse events can necessitate cancer treatment being put on hold or stopped, which could compromise patient survival. In addition to increasing the risk of thrombotic adverse events, cancer therapies may lead to an increased risk of bleeding, especially in treatments with vascular endothelial growth factor inhibitors. Therefore, we can define vasculo-oncology as a part of the cardio-oncology specialty; its aims are to predict, prevent, screen, and treat vascular toxicity related to cancer treatments. While the level of evidence is low regarding the management of vascular toxicity during cancer therapy, cardiologists and specialists in vascular diseases should closely collaborate with oncologists and hematologists to determine the optimal strategy for each patient.

Cardiotoxicity Induced by Protein Kinase Inhibitors in Patients with Cancer

Kinase inhibitors (KIs) represent a growing class of drugs directed at various protein kinases and used in the treatment of both solid tumors and hematologic malignancies. It is a heterogeneous group of compounds that are widely applied not only in different types of tumors but also in tumors that are positive for a specific predictive factor. This review summarizes common cardiotoxic effects of KIs, including hypertension, arrhythmias with bradycardia and QTc prolongation, and cardiomyopathy that can lead to heart failure, as well as less common effects such as fluid retention, ischemic heart disease, and elevated risk of thromboembolic events. The guidelines for cardiac monitoring and management of the most common cardiotoxic effects of protein KIs are discussed. Potential signaling pathways affected by KIs and likely contributing to cardiac damage are also described. Finally, the need for further research into the molecular mechanisms underlying the cardiovascular toxicity of these drugs is indicated.

Mechanistic and Clinical Overview Cardiovascular Toxicity of BRAF and MEK Inhibitors: JACC: CardioOncology State-of-the-Art Review

Rapidly accelerated fibrosarcoma B-type (BRAF) and mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors have revolutionized melanoma treatment. Approximately half of patients with melanoma harbor a BRAF gene mutation with subsequent dysregulation of the RAF-MEK-ERK signaling pathway. Targeting this pathway with BRAF and MEK blockade results in control of cell proliferation and, in most cases, disease control. These pathways also have cardioprotective effects and are necessary for normal vascular and cardiac physiology. BRAF and MEK inhibitors are associated with adverse cardiovascular effects including hypertension, left ventricular dysfunction, venous thromboembolism, atrial arrhythmia, and electrocardiographic QT interval prolongation. These effects may be underestimated in clinical trials. Baseline cardiovascular assessment and follow-up, including serial imaging and blood pressure assessment, are essential to balance optimal anti-cancer therapy while minimizing cardiovascular side effects. In this review, an overview of BRAF/MEK inhibitor-induced cardiovascular toxicity, the mechanisms underlying these, and strategies for surveillance, prevention, and treatment of these effects are provided.

Cardiomyocyte BRAF and type 1 RAF inhibitors promote cardiomyocyte and cardiac hypertrophy in mice in vivo

The extracellular signal-regulated kinase 1/2 (ERK1/2) cascade promotes cardiomyocyte hypertrophy and is cardioprotective, with the three RAF kinases forming a node for signal integration. Our aims were to determine if BRAF is relevant for human heart failure, whether BRAF promotes cardiomyocyte hypertrophy, and if Type 1 RAF inhibitors developed for cancer (that paradoxically activate ERK1/2 at low concentrations: the 'RAF paradox') may have the same effect. BRAF was up-regulated in heart samples from patients with heart failure compared with normal controls. We assessed the effects of activated BRAF in the heart using mice with tamoxifen-activated Cre for cardiomyocyte-specific knock-in of the activating V600E mutation into the endogenous gene. We used echocardiography to measure cardiac dimensions/function. Cardiomyocyte BRAFV600E induced cardiac hypertrophy within 10 d, resulting in increased ejection fraction and fractional shortening over 6 weeks. This was associated with increased cardiomyocyte size without significant fibrosis, consistent with compensated hypertrophy. The experimental Type 1 RAF inhibitor, SB590885, and/or encorafenib (a RAF inhibitor used clinically) increased ERK1/2 phosphorylation in cardiomyocytes, and promoted hypertrophy, consistent with a 'RAF paradox' effect. Both promoted cardiac hypertrophy in mouse hearts in vivo, with increased cardiomyocyte size and no overt fibrosis. In conclusion, BRAF potentially plays an important role in human failing hearts, activation of BRAF is sufficient to induce hypertrophy, and Type 1 RAF inhibitors promote hypertrophy via the 'RAF paradox'. Cardiac hypertrophy resulting from these interventions was not associated with pathological features, suggesting that Type 1 RAF inhibitors may be useful to boost cardiomyocyte function.

Cardiac Effects of BRAF and MEK Inhibitors: Mechanisms and Clinical Management

PURPOSE OF REVIEW

The identification of BRAF mutation prompted the development of new class of targeted therapy for treating melanoma: BRAF inhibitors and MEK inhibitors. Cardiovascular events have been reported with these treatments and could counterbalance their long-term maintenance.

RECENT FINDINGS

LVEF decrease due to BRAF and MEK inhibitors appears fairly common (10%) but usually not severe, without impact on patient outcomes. To date, no treatment options have been tested to prevent or to treat a decrease of LVEF associated with BRAF and MEK inhibitors. QTc prolongation was observed in 3% and arterial hypertension in 20% during treatment but only one-third of cases required a therapeutic change. BRAF and MEK inhibitors have revolutionized the management and the prognosis of melanoma patients. Cardio-oncology units may be useful for a better care of potential cardiac toxicity and particularly to inappropriately avoid discontinuing BRAF and MEK inhibitors.

Treatment of Plexiform Neurofibromas with MEK Inhibitors: First Results with a New Therapeutic Option

Neurofibromatosis type-1 (NF1)-associated plexiform neurofibromas (PN) are peripheral nerve sheath tumors that can significantly affect the quality of life. Until recently, surgery was the only treatment for these tumors. However, in most cases, surgery cannot achieve complete tumor removal and carries a high risk of postoperative deficits. Therefore, the recent approval of the MEK inhibitor selumetinib for the treatment of NF1-associated PN provides a long-awaited novel therapeutic option. Here, we report our experience with MEK inhibitor treatment in 12 pediatric NF1 patients with inoperable symptomatic PN. Eight patients received trametinib (median therapy duration 12.13 months and range 4-29 months), and four patients received selumetinib (median therapy duration 6.25 months and range 4-11 months). Volumetric magnetic resonance imaging (MRI) after 6 months of treatment was available for seven trametinib patients (median tumor volume reduction of 26.5% and range 11.3-55.7%) and two selumetinib patients (21.3% tumor volume reduction in one patient and +3% tumor volume change in the other one). All patients reported clinical benefits such as improved range of motion or reduced disfigurement. Therapy-related adverse events occurred in 58.3% of patients and mainly consisted of skin toxicity, paronychia, and gastrointestinal symptoms. Two patients discontinued trametinib treatment after 14 and 29 months when severe skin toxicity occurred and no further reduction of tumor size was observed. In one patient, discontinuation of therapy resulted in a 27.2% tumor volume increase as demonstrated on volumetric MRI 6 months later. Our data show that MEK inhibition is a novel therapeutic approach for inoperable PN with promising results and a manageable safety profile.

Cancer Chemotherapy-Induced Sinus Bradycardia: A Narrative Review of a Forgotten Adverse Effect of Cardiotoxicity

Cardiotoxicity is a common adverse effect of anticancer drugs (ACDs), including the so-called targeted drugs, and increases morbidity and mortality in patients with cancer. Attention has focused mainly on ACD-induced heart failure, myocardial ischemia, hypertension, thromboembolism, QT prolongation, and tachyarrhythmias. Yet, although an increasing number of ACDs can produce sinus bradycardia (SB), this proarrhythmic effect remains an underappreciated complication, probably because of its low incidence and severity since most patients are asymptomatic. However, SB merits our interest because its incidence increases with the aging of the population and cancer is an age-related disease and because SB represents a risk factor for QT prolongation. Indeed, several ACDs that produce SB also prolong the QT interval. We reviewed published reports on ACD-induced SB from January 1971 to November 2020 using the PubMed and EMBASE databases. Published reports from clinical trials, case reports, and recent reviews were considered. This review describes the associations between ACDs and SB, their clinical relevance, risk factors, and possible mechanisms of onset and treatment.

Peptide Receptor Radionuclide Therapy in Thyroid Cancer

The treatment options that are currently available for management of metastatic, progressive radioactive iodine (RAI)-refractory differentiated thyroid cancers (DTCs), and medullary thyroid cancers (MTCs) are limited. While there are several systemic targeted therapies, such as tyrosine kinase inhibitors, that are being evaluated and implemented in the treatment of these cancers, such therapies are associated with serious, sometimes life-threatening, adverse events. Peptide receptor radionuclide therapy (PRRT) has the potential to be an effective and safe modality for treating patients with somatostatin receptor (SSTR)+ RAI-refractory DTCs and MTCs. MTCs and certain sub-types of RAI-refractory DTCs, such as Hürthle cell cancers which are less responsive to conventional modalities of treatment, have demonstrated a favorable response to treatment with PRRT. While the current literature offers hope for utilization of PRRT in thyroid cancer, several areas of this field remain to be investigated further, especially head-to-head comparisons with other systemic targeted therapies. In this review, we provide a comprehensive outlook on the current translational and clinical data on the use of various PRRTs, including diagnostic utility of somatostatin analogs, theranostic properties of PRRT, and the potential areas for future research.

Protective effects of dioscin against isoproterenol-induced cardiac hypertrophy via adjusting PKCε/ERK-mediated oxidative stress

Cardiac hypertrophy (CH) plays a central role in cardiac remodeling and is an independent risk factor for cardiac events. It is imperative to find drugs with protective effect on CH. Dioscin, one natural product, shows various pharmacological activities, and PKCepsilon (PKCε) plays an important role in the physiological hypertrophic responses. Thus, we aimed to investigate the possible protective effect of dioscin on CH through PKCε. In the present study, the isoproterenol (ISO)-induced H9C2 cells and primary cardiomyocytes models, and the ISO-induced rat model were established, and the pharmacodynamics and mechanism of dioscin were investigated. In vitro results prompted that, dioscin significantly improved ISO-induced cardiomyocyte hypertrophy, decreased the levels of cell size, protein content of single cell, reactive oxygen species, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), beta-myosin heavy chain (β-MHC). Moreover, in vivo, changes in histopathological of the animals caused by ISO are improved by dioscin. And dioscin decreased the index of CH and the levels of CK, MDA, LDH, and increased the levels of GSH, SOD and GSH-Px. Mechanism research showed that dioscin inhibited the expression levels of PKCε, and affected the expression levels of p-MEK, p-ERK, Nrf2, Keap1 and HO-1 to inhibit oxidative stress. In addition, the results of ISO-induced CH in PKCε siRNA transfected H9C2 cells and C57BL/6 mice further showed that the protective effect of dioscin on CH, which was mediated by inhibition of PKCε/ERK signal pathway. In summary, dioscin can effectively inhibit CH by regulating PKCε-mediated oxidative stress, which should be considered as one potent candidate for new drug research and development to treat CH in the future.

Pathophysiology, diagnosis and management of cardiac toxicity induced by immune checkpoint inhibitors and BRAF and MEK inhibitors

Immune checkpoint inhibitors (ICIs) and BRAF and MEK inhibitors (BRAFi/MEKi) have drastically improved the outcome of melanoma patients. ICIs can induce myocarditis, a rare immune related adverse event (irAE) with an estimated lethality of 50%. BRAFi/MEKi may induce left ventricular ejection fraction decrease, hypertension or QT interval prolongation. While the BRAFi/MEKi induced cardiotoxicity is often reversible upon treatment discontinuation or dose adaptation and symptomatic therapy is often sufficient to restore cardiac function, the treatment of ICI-induced myocarditis mainly relies on high dose corticosteroids. There is no established therapy for steroid resistant myocarditis, yet various drugs have been reported to improve outcome. Shared epitopes between melanoma cells and cardiac tissue are thought to underlie the development of ICIs induced myocarditis. The mechanism of BRAFi/MEKi induced cardiotoxicity appears to be related to the Ras-Raf-MEK-ERK pathway in cardiomyocyte repair, survival and proliferation. With the emerging application of ICI-BRAFi/MEKi combinations, so called triplet therapies, differentiating between these two types of cardiotoxicity will become important for appropriate patient management. In this article we provide a summary of the existing literature on the pathophysiology, diagnosis and management of cardiotoxicity of melanoma therapies.

The anti-cancer drug dabrafenib is not cardiotoxic and inhibits cardiac remodelling and fibrosis in a murine model of hypertension

Raf kinases signal via extracellular signal-regulated kinases 1/2 (ERK1/2) to drive cell division. Since activating mutations in BRAF (B-Raf proto-oncogene, serine/threonine kinase) are highly oncogenic, BRAF inhibitors including dabrafenib have been developed for cancer. Inhibitors of ERK1/2 signalling used for cancer are cardiotoxic in some patients, raising the question of whether dabrafenib is cardiotoxic. In the heart, ERK1/2 signalling promotes not only cardiomyocyte hypertrophy and is cardioprotective but also promotes fibrosis. Our hypothesis is that ERK1/2 signalling is not required in a non-stressed heart but is required for cardiac remodelling. Thus, dabrafenib may affect the heart in the context of, for example, hypertension. In experiments with cardiomyocytes, cardiac fibroblasts and perfused rat hearts, dabrafenib inhibited ERK1/2 signalling. We assessed the effects of dabrafenib (3 mg/kg/d) on male C57BL/6J mouse hearts in vivo. Dabrafenib alone had no overt effects on cardiac function/dimensions (assessed by echocardiography) or cardiac architecture. In mice treated with 0.8 mg/kg/d angiotensin II (AngII) to induce hypertension, dabrafenib inhibited ERK1/2 signalling and suppressed cardiac hypertrophy in both acute (up to 7 d) and chronic (28 d) settings, preserving ejection fraction. At the cellular level, dabrafenib inhibited AngII-induced cardiomyocyte hypertrophy, reduced expression of hypertrophic gene markers and almost completely eliminated the increase in cardiac fibrosis both in interstitial and perivascular regions. Dabrafenib is not overtly cardiotoxic. Moreover, it inhibits maladaptive hypertrophy resulting from AngII-induced hypertension. Thus, Raf is a potential therapeutic target for hypertensive heart disease and drugs such as dabrafenib, developed for cancer, may be used for this purpose.

Trametinib-associated Hyponatremia in a Child With Low-grade Glioma is Not Seen Following Treatment With Alternative MEK Inhibitor

Molecularly targeted therapy with MEK inhibitors has been increasingly incorporated into the treatment of pediatric low-grade gliomas, but this promising therapy is associated with distinctive and specific toxicities. Understanding life-threatening MEK inhibitor toxicities and their management is critical to MEK inhibitor safety, especially among young children. This report describes severe hyponatremia associated with trametinib in an infant with progressive low-grade glioma without underlying endocrine dysfunction, which recurred despite significant dose reduction. Therapy with an alternative MEK inhibitor, binimetinib, provided excellent tumor response without hyponatremia, suggesting that some toxicities may be avoided by changing MEK inhibitor agents within the same class.

Cardiotoxicity of chemotherapy and targeted agents

The evolution of cancer treatment and development of new classes of anticancer therapies have continued to revolutionize the field of oncology. New therapies including targeted agents, immunotherapies, and adoptive cell transfer have allowed for exciting survival benefit progress for patients. However, the novel nature of these therapies as well as the longer survival periods of patients receiving them has highlighted the various side effects of anticancer therapies. Cardiotoxicity has emerged as a major side effect of anticancer treatment and can present both acutely during treatment and chronically even years after treatment has been completed. This work compiles the cardiotoxic side effects of various chemotherapeutic and targeted anticancer therapies and their management.

Research progress of MEK1/2 inhibitors and degraders in the treatment of cancer

Mitogen-activated protein kinase kinases 1 and 2 (MEK1/2) are the crucial part of the RAS-RAF-MEK-ERK pathway (or ERK pathway), which is involved in the regulation of various cellular processes including proliferation, survival, and differentiation et al. Targeting MEK has become an important strategy for cancer therapy, and 4 MEK inhibitors (MEKis) have been approved by FDA to date. However, the application of MEKis is limited due to acquired resistance under long-term treatment. Fortunately, an emerging technology, named proteolysis targeting chimera (PROTAC), could break through this limitation by inducing MEK1/2 degradation. Compared to MEKis, MEK1/2 PROTAC is rarely studied and only three MEK1/2 PROTAC molecules, have been reported until now. This paper will outline the ERK pathway and the mechanism and research progress of MEK1/2 inhibitors, but focus on the development of MEK degraders and their optimization strategies. PAC-1 strategy which can induce MEK degradation indirectly, other PROTACs on ERK pathway, the advantages and challenges of PROTAC technology will be subsequently discussed.

The MEK/ERK Module Is Reprogrammed in Remodeling Adult Cardiomyocytes

Fetal and hypertrophic remodeling are hallmarks of cardiac restructuring leading chronically to heart failure. Since the Ras/Raf/MEK/ERK cascade (MAPK) is involved in the development of heart failure, we hypothesized, first, that fetal remodeling is different from hypertrophy and, second, that remodeling of the MAPK occurs. To test our hypothesis, we analyzed models of cultured adult rat cardiomyocytes as well as investigated myocytes in the failing human myocardium by western blot and confocal microscopy. Fetal remodeling was induced through endothelial morphogens and monitored by the reexpression of Acta2, Actn1, and Actb. Serum-induced hypertrophy was determined by increased surface size and protein content of cardiomyocytes. Serum and morphogens caused reprogramming of Ras/Raf/MEK/ERK. In both models H-Ras, N-Ras, Rap2, B- and C-Raf, MEK1/2 as well as ERK1/2 increased while K-Ras was downregulated. Atrophy, MAPK-dependent ischemic resistance, loss of A-Raf, and reexpression of Rap1 and Erk3 highlighted fetal remodeling, while A-Raf accumulation marked hypertrophy. The knock-down of B-Raf by siRNA reduced MAPK activation and fetal reprogramming. In conclusion, we demonstrate that fetal and hypertrophic remodeling are independent processes and involve reprogramming of the MAPK.

The Use of MEK Inhibitors in Neurofibromatosis Type 1-Associated Tumors and Management of Toxicities

Early-phase clinical trials using oral inhibitors of MEK, the mitogen-activated protein kinase kinase, have demonstrated benefit for patients with neurofibromatosis type 1 (NF1)-associated tumors, particularly progressive low-grade gliomas and plexiform neurofibromas. Given this potential of MEK inhibition as an effective medical therapy, the use of targeted agents in the NF1 population is likely to increase substantially. For clinicians with limited experience prescribing MEK inhibitors, concern about managing these treatments may be a barrier to use. In this manuscript, the Clinical Care Advisory Board of the Children's Tumor Foundation reviews the published experience with MEK inhibitors in NF1 and outlines recommendations for side-effect management, as well as monitoring guidelines. These recommendations can serve as a beginning framework for NF providers seeking to provide the most effective treatments for their patients. IMPLICATIONS FOR PRACTICE: Neurofibromatosis type 1 (NF1) clinical care is on the cusp of a transformative shift. With the success of recent clinical trials using MEK inhibitors, an increasing number of NF1 patients are being treated with MEK inhibitors for both plexiform neurofibromas and low-grade gliomas. The use of MEK inhibitors is likely to increase substantially in NF1. Given these changes, the Clinical Care Advisory Board of the Children's Tumor Foundation has identified a need within the NF1 clinical community for guidance for the safe and effective use of MEK inhibitors for NF1-related tumors. This article provides a review of the published experience of MEK inhibitors in NF1 and provides recommendations for monitoring and management of side effects.

Targeting hallmarks of cancer to enhance radiosensitivity in gastrointestinal cancers

Radiotherapy is used in the treatment of approximately 50% of all malignancies including gastrointestinal cancers. Radiation can be given prior to surgery (neoadjuvant radiotherapy) to shrink the tumour or after surgery to kill any remaining cancer cells. Radiotherapy aims to maximize damage to cancer cells, while minimizing damage to healthy cells. However, only 10-30% of patients with rectal cancer or oesophageal cancer have a pathological complete response to neoadjuvant chemoradiation therapy, with the rest suffering the negative consequences of toxicities and delays to surgery with no clinical benefit. Furthermore, in pancreatic cancer, neoadjuvant chemoradiation therapy results in a pathological complete response in only 4% of patients and a partial pathological response in only 31%. Resistance to radiation therapy is polymodal and associated with a number of biological alterations both within the tumour itself and in the surrounding microenvironment including the following: altered cell cycle; repopulation by cancer stem cells; hypoxia; altered management of oxidative stress; evasion of apoptosis; altered DNA damage response and enhanced DNA repair; inflammation; and altered mitochondrial function and cellular energetics. Radiosensitizers are needed to improve treatment response to radiation, which will directly influence patient outcomes in gastrointestinal cancers. This article reviews the literature to identify strategies - including DNA-targeting agents, antimetabolic agents, antiangiogenics and novel immunotherapies - being used to enhance radiosensitivity in gastrointestinal cancers according to the hallmarks of cancer. Evidence from radiosensitizers from in vitro and in vivo models is documented and the action of radiosensitizers through clinical trial data is assessed.

Interference with ERK-dimerization at the nucleocytosolic interface targets pathological ERK1/2 signaling without cardiotoxic side-effects

Dysregulation of extracellular signal-regulated kinases (ERK1/2) is linked to several diseases including heart failure, genetic syndromes and cancer. Inhibition of ERK1/2, however, can cause severe cardiac side-effects, precluding its wide therapeutic application. ERK^T188-autophosphorylation was identified to cause pathological cardiac hypertrophy. Here we report that interference with ERK-dimerization, a prerequisite for ERK^T188-phosphorylation, minimizes cardiac hypertrophy without inducing cardiac adverse effects: an ERK-dimerization inhibitory peptide (EDI) prevents ERK^T188-phosphorylation, nuclear ERK1/2-signaling and cardiomyocyte hypertrophy, protecting from pressure-overload-induced heart failure in mice whilst preserving ERK1/2-activity and cytosolic survival signaling. We also examine this alternative ERK1/2-targeting strategy in cancer: indeed, ERK^T188-phosphorylation is strongly upregulated in cancer and EDI efficiently suppresses cancer cell proliferation without causing cardiotoxicity. This powerful cardio-safe strategy of interfering with ERK-dimerization thus combats pathological ERK1/2-signaling in heart and cancer, and may potentially expand therapeutic options for ERK1/2-related diseases, such as heart failure and genetic syndromes.

Drugs targeting dysregulated ERK1/2 signaling can cause severe cardiac side effects, precluding their wide therapeutic application. Here, a new and cardio-safe targeting strategy is presented that interferes with ERK dimerization to prevent pathological ERK1/2 signaling in the heart and cancer.

Left ventricular ejection fraction decrease related to BRAF and/or MEK inhibitors in metastatic melanoma patients: A retrospective analysis

BRAF and MEKis have revolutionized the management of BRAF^V600‐mutated melanoma patients. Left ventricular ejection fraction decrease (LVEF‐D) related to these treatments has not been thoroughly evaluated to date. The main objective of this study was to describe characteristics of LVEF‐D in melanoma patients treated with BRAF and/or MEKis. Metastatic melanoma patients treated with BRAF and/or MEKis between March 1, 2012 and May 18, 2018 were included retrospectively (Lyon Sud University Hospital, Hospices Civils de Lyon). LVEF‐D was defined as a reduction in LVEF ≥10% from baseline to a value <55%; normalization was defined as a value ≥55%. Among the 88 patients included, 12 (13.6%) experienced a LVEF‐D, including 10 grade 2 and 2 grade 3. The median onset of which was 11 months (IQR [3‐21]). No patient previously treated with beta‐blockers (n = 12) experienced a LVEF‐D. Analysis of laboratory parameters, electrocardiogram, and transthoracic echocardiography during the follow‐up did not find any predictive marker of LVEF‐D. All patients who benefited from a specific treatment of LVEF‐D had a normalization of LVEF at the end of follow‐up. LVEF recovery was significantly better for patients treated with angiotensin converting enzyme inhibitors and beta‐blockers than those who did not (P = .019). Ophthalmological adverse events were significantly more frequent in patients who experienced a LVEF‐D (P = .006) and the latter did not influence overall‐survival (P = .117) or progression‐free‐survival (P = .297). LVEF‐D is a common and easily manageable adverse event due to BRAF and MEKis. Its association with ocular toxicity suggests a close ophthalmological monitoring when LVEF‐D occurs.

Proceedings From the Global Cardio-Oncology Summit: The Top 10 Priorities to Actualize for CardioOncology

The discipline of cardio-oncology has expanded at a remarkable pace. Recent developments and challenges to clinicians who practice cardio-oncology were presented at the Global Cardio-Oncology Summit on October 3 to 4, 2019, in São Paulo, Brazil. Here, we present the top 10 priorities for our field that were discussed at the meeting, and also detail a potential path forward to address these challenges. Defining robust predictors of cardiotoxicity, clarifying the role of cardioprotection, managing and preventing thromboembolism, improving hematopoietic stem cell transplant outcomes, personalizing cardiac interventions, building the cardio-oncology community, detecting and treating cardiovascular events associated with immunotherapy, understanding tyrosine kinase inhibitor cardiotoxicity, and enhancing survivorship care are all priorities for the field. The path forward requires a commitment to research, education, and excellence in clinical care to improve our patients' lives.

[Supportive therapy and management of side effects in dermato-oncology]

In the context of supportive therapy, possible complaints which may be caused by the cancer itself, by the antitumoral therapy or by psychosocial concerns are considered. Due to the introduction of new anticancer drugs in dermato-oncology, clinicians are confronted with a novel spectrum of adverse events. There are a number of inflammatory, immune-mediated side effects caused by immunotherapies, which can affect virtually any organ. Targeted therapies also have specific side effects. Basically, the management of adverse events depends on their severity. Besides treatment breaks and dosage modifications, immunotherapy-related adverse events are treated with systemic immunosuppressants. Supportive symptomatic therapy is offered. The additional consideration of psychosocial problems can improve quality of life of cancer patients.

Cardiomyocyte Homeodomain-Interacting Protein Kinase 2 Maintains Basal Cardiac Function via Extracellular Signal-Regulated Kinase Signaling

BACKGROUND

Cardiac kinases play a critical role in the development of heart failure, and represent potential tractable therapeutic targets. However, only a very small fraction of the cardiac kinome has been investigated. To identify novel cardiac kinases involved in heart failure, we used an integrated transcriptomics and bioinformatics analysis and identified Homeodomain-Interacting Protein Kinase 2 (HIPK2) as a novel candidate kinase. The role of HIPK2 in cardiac biology is unknown.

METHODS

We used the Expression2Kinase algorithm for the screening of kinase targets. To determine the role of HIPK2 in the heart, we generated cardiomyocyte (CM)-specific HIPK2 knockout and heterozygous mice. Heart function was examined by echocardiography, and related cellular and molecular mechanisms were examined. Adeno-associated virus serotype 9 carrying cardiac-specific constitutively active MEK1 (TnT-MEK1-CA) was administrated to rescue cardiac dysfunction in CM-HIPK2 knockout mice.

RESULTS

To our knowledge, this is the first study to define the role of HIPK2 in cardiac biology. Using multiple HIPK2 loss-of-function mouse models, we demonstrated that reduction of HIPK2 in CMs leads to cardiac dysfunction, suggesting a causal role in heart failure. It is important to note that cardiac dysfunction in HIPK2 knockout mice developed with advancing age, but not during development. In addition, CM-HIPK2 knockout mice and CM-HIPK2 heterozygous mice exhibited a gene dose-response relationship of CM-HIPK2 on heart function. HIPK2 expression in the heart was significantly reduced in human end-stage ischemic cardiomyopathy in comparison to nonfailing myocardium, suggesting a clinical relevance of HIPK2 in cardiac biology. In vitro studies with neonatal rat ventricular CMscorroborated the in vivo findings. Specifically, adenovirus-mediated overexpression of HIPK2 suppressed the expression of heart failure markers, NPPA and NPPB, at basal condition and abolished phenylephrine-induced pathological gene expression. An array of mechanistic studies revealed impaired extracellular signal-regulated kinase 1/2 signaling in HIPK2-deficient hearts. An in vivo rescue experiment with adeno-associated virus serotype 9 TnT-MEK1-CA nearly abolished the detrimental phenotype of knockout mice, suggesting that impaired extracellular signal-regulated kinase signaling mediated apoptosis as the key factor driving the detrimental phenotype in CM-HIPK2 knockout mice hearts.

CONCLUSIONS

Taken together, these findings suggest that CM-HIPK2 is required to maintain normal cardiac function via extracellular signal-regulated kinase signaling.

Adverse events associated with encorafenib plus binimetinib in the COLUMBUS study: incidence, course and management

BACKGROUND

Dual inhibition of the mitogen-activated protein kinase pathway with BRAF/MEK inhibitor (BRAFi/MEKi) therapy is a standard treatment for BRAFV600-mutant metastatic melanoma and has historically been associated with grade III pyrexia or photosensitivity depending on the combination used. The objective of this study was to fully describe adverse events from the COLUMBUS study evaluating the most recent BRAF/MEK inhibitor combination encorafenib+binimetinib.

PATIENTS AND METHODS

Patients with locally advanced, unresectable or metastatic BRAFV600-mutant melanoma were randomised to receive encorafenib 450 mg once daily plus binimetinib 45 mg twice daily, encorafenib 300 mg once daily or vemurafenib 960 mg twice daily. Adverse events that represent known effects of available BRAFi and/or MEKi were evaluated.

RESULTS

The safety population included a total of 570 patients (encorafenib+binimetinib = 192; encorafenib = 192; vemurafenib = 186). Median duration of exposure was longer with encorafenib+binimetinib (51 weeks) than with encorafenib (31 weeks) or vemurafenib (27 weeks). Common BRAFi/MEKi toxicities with encorafenib+binimetinib were generally manageable, reversible and infrequently associated with discontinuation. Pyrexia was less frequent with encorafenib+binimetinib (18%) and encorafenib (16%) than with vemurafenib (30%) and occurred later in the course of therapy with encorafenib+binimetinib (median time to first onset: 85 days versus 2.5 days and 19 days, respectively). The incidence of photosensitivity was lower with encorafenib+binimetinib (5%) and encorafenib (4%) than with vemurafenib (30%). The incidence of serous retinopathy was higher with encorafenib+binimetinib (20%) than with encorafenib (2%) or vemurafenib (2%), but no patients discontinued encorafenib+binimetinib because of this event.

CONCLUSION

Encorafenib+binimetinib is generally well tolerated and has a low discontinuation rate in patients with BRAFV600-mutant melanoma, with a distinct safety profile as compared with other anti-BRAF/MEK targeted therapies.

TRIAL REGISTRATION

ClinicalTrials.gov (Identifier: NCT01909453) and with EudraCT (number 2013-001176-38).

Temporal trends, ethnic determinants, and short-term and long-term risk of cardiac death in cancer patients: a cohort study

BACKGROUND

We evaluated the risk of cardiac death in patients with prior cancer diagnoses and compared risk by cancer type and ethnicity in a large US population.

METHOD

Utilizing the Surveillance, Epidemiology, and End Results database, data on patients with a cancer diagnosis between 2000 and 2014 were obtained. We calculated the standardized mortality ratio (SMR) of cardiac death after a cancer diagnosis and the excess risk per 10,000 person-years. We stratified the analysis according to the time interval between cancer and cardiac events, cancer site, cancer stage, and race.

RESULTS

A total of 4,671,989 patients with a cancer diagnosis were included, of which 163,255 died due to cardiac causes within 10 years of diagnosis. We found a significantly higher rate of cardiac death for cancer patients [SMR=1.16, 95% confidence interval (CI) 1.15-1.16] compared to the general population. When observed for each cancer site, the highest SMR was after a diagnosis of hepatocellular carcinoma (SMR=2.58, 95% CI 2.45-2.72), pancreatic cancer (SMR=2.36, 95% CI 2.25-2.47), and lung cancer (SMR=2.30, 95% CI 2.27-2.34). Patients with metastatic disease had a higher rate of cardiac death (SMR=2.16, 95% CI 2.13-2.19). When stratified by ethnicity, SMR for cardiac death was 1.76, 2.28, 3.68, 2.65, and 1.84 for whites, blacks, American Indians/Alaska Natives, Asians/Pacific Islanders, and Hispanics, respectively.

CONCLUSIONS

Cancer patients are more vulnerable to cardiac death than the general population, especially those with nonwhite ethnicity; liver, lung, and pancreatic cancers; and history of metastasis. Healthcare providers should be aware of this risk and pay particular attention to the highest-risk groups.

Cardiovascular Adverse Events Associated With BRAF and MEK Inhibitors: A Systematic Review and Meta-analysis

IMPORTANCE

Cardiovascular adverse events (CVAEs) after treatment with BRAF and MEK inhibitors in patients with melanoma remain incompletely characterized.

OBJECTIVE

To determine the association of BRAF and MEK inhibitor treatment with CVAEs in patients with melanoma compared with BRAF inhibitor monotherapy.

DATA SOURCES

PubMed, Cochrane, and Web of Science were systematically searched for keywords vemurafenib, dabrafenib, encorafenib, trametinib, binimetinib, and cobinimetinib from database inception through November 30, 2018.

STUDY SELECTION

Randomized clinical trials reporting on CVAEs in patients with melanoma being treated with BRAF and MEK inhibitors compared with patients with melanoma being treated with BRAF inhibitor monotherapy were selected.

DATA EXTRACTION AND SYNTHESIS

Data assessment followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Pooled relative risks (RRs) and 95% CIs were determined using random-effects and fixed-effects analyses. Subgroup analyses were conducted to assess study-level characteristics associated with CVAEs.

MAIN OUTCOMES AND MEASURES

The selected end points were pulmonary embolism, a decrease in left ventricular ejection fraction, arterial hypertension, myocardial infarction, atrial fibrillation, and QTc interval prolongation. All-grade and high-grade (≥3) CVAEs were recorded.

RESULTS

Overall, 5 randomized clinical trials including 2317 patients with melanoma were selected. Treatment with BRAF and MEK inhibitors was associated with an increased risk of pulmonary embolism (RR, 4.36; 95% CI, 1.23-15.44; P = .02), a decrease in left ventricular ejection fraction (RR, 3.72; 95% CI, 1.74-7.94; P < .001), and arterial hypertension (RR, 1.49; 95% CI, 1.12-1.97; P = .005) compared with BRAF inhibitor monotherapy. The RRs for myocardial infarction, atrial fibrillation, and QTc prolongation were similar between the groups. These results were consistent when assessing high-grade CVAEs (left ventricular ejection fraction: RR, 2.79; 95% CI, 1.36-5.73; P = .005; I2 = 29%; high-grade arterial hypertension: RR, 1.54; 95% CI, 1.14-2.08; P = .005; I2 = 0%), but RRs for high-grade pulmonary embolism were similar between groups. A higher risk of a decrease in left ventricular ejection fraction was associated with patients with a mean age younger than 55 years (RR, 26.50; 95% CI, 3.58-196.10; P = .001), and the associated risk of pulmonary embolism was higher for patients with a mean follow-up time longer than 15 months (RR, 7.70; 95% CI, 1.40-42.12; P = .02).

CONCLUSIONS AND RELEVANCE

Therapy with BRAF and MEK inhibitors was associated with a higher risk of CVAEs compared with BRAF inhibitor monotherapy. The findings may help to balance between beneficial melanoma treatment and cardiovascular morbidity and mortality.

Endothelial ERK1/2 signaling maintains integrity of the quiescent endothelium

The endothelial ERK1/2 pathway plays a crucial role in the maintenance of endothelial homeostasis. Its suppression results in activation of TGFβ signaling, leading to hypertension, renal failure, fibrosis, and sudden death, findings similar to those observed in patients treated with anti-VEGF agents.

To define the role of ERK1/2 signaling in the quiescent endothelium, we induced endothelial Erk2 knockout in adult Erk1^−/− mice. This resulted in a rapid onset of hypertension, a decrease in eNOS expression, and an increase in endothelin-1 plasma levels, with all mice dying within 5 wk. Immunostaining and endothelial fate mapping showed a robust increase in TGFβ signaling leading to widespread endothelial-to-mesenchymal transition (EndMT). Fibrosis affecting the cardiac conduction system was responsible for the universal lethality in these mice. Other findings included renal endotheliosis, loss of fenestrated endothelia in endocrine organs, and hemorrhages. An ensemble computational intelligence strategy, comprising deep learning and probabilistic programing of RNA-seq data, causally linked the loss of ERK1/2 in HUVECs in vitro to activation of TGFβ signaling, EndMT, suppression of eNOS, and induction of endothelin-1 expression. All in silico predictions were verified in vitro and in vivo. In summary, these data establish the key role played by ERK1/2 signaling in the maintenance of vascular normalcy.

Tolerability of BRAF/MEK inhibitor combinations: adverse event evaluation and management

The inhibition of the mitogen-activated protein kinases signalling pathway through combined use of BRAF and MEK inhibitors (BRAFi+MEKi) represents an established therapeutic option in patients with BRAF-mutated, advanced melanoma. These efficient therapies are well tolerated with mostly moderate and reversible side effects and a discontinuation rate due to adverse events of 11.5%-15.7%. Median duration of therapy ranges between 8.8 and 11.7 months. Based on data from confirmatory trials, safety profiles of three BRAFi+MEKi combinations were reviewed, that is, dabrafenib plus trametinib, vemurafenib plus cobimetinib and encorafenib plus binimetinib. Many adverse events are class effects, such as cutaneous, gastrointestinal, ocular, cardiac and musculoskeletal events; some adverse events are substance associated. Fever (dabrafenib) and photosensitivity (vemurafenib) are the most common and clinically prominent examples. Other adverse events are less frequent and the association to one substance is less strong such as anaemia, facial paresis (encorafenib), neutropenia (dabrafenib), skin rash, QTc prolongation and increased liver function tests (vemurafenib). This narrative review provides recommendations for monitoring, adverse event evaluation and management focusing on the clinically relevant side effects of the three regimens.