Cardiovascular toxicity of PI3Kα inhibitors

Systematical Evaluation of the Structure-Cardiotoxicity Relationship of 7-Azaindazole-based PI3K Inhibitors Designed by Bioisosteric Approach

A growing concern of cardiotoxicity induced by PI3K inhibitors has raised the requirements to evaluate the structure-cardiotoxicity relationship (SCR) in the development process of novel inhibitors. Based on three bioisosteric 7-azaindazole-based candidate inhibitors namely FD269, FD268 and FD274 that give same order of inhibitory concentration 50% (IC50) magnitude against PI3Ks, in this work, we proposed to systematically evaluate the SCR of 7-azaindazole-based PI3K inhibitors designed by bioisosteric approach. The 24-h lethal concentrations 50% (LC50) of FD269, FD268 and FD274 against zebrafish embryos were 0.35, 4.82 and above 50 μM (not detected), respectively. Determination of the heart rate, pericardial and yolk-sac areas and vascular malformation confirmed the remarkable reduction in the cardiotoxicity of from FD269 to FD268 and to FD274. The IC50s of all three compounds against the hERG channel were tested on the CHO cell line that constitutively expressing hERG channel, which were all higher than 20 μM. The transcriptomic analysis revealed that FD269 and FD268 induced the up-regulation of noxo1b, which encodes a subunit of an NADPH oxidase evoking the oxidative stress. Furthermore, immunohistochemistry tests confirmed the structure-dependent attenuation of the overproduction of ROS and cardiac apoptosis. Our results verified the feasibility of bioisosteric replacement to attenuate the cardiotoxicity of 7-azaindazole-based PI3K inhibitors, suggesting that the screening for PI3K inhibitors with both high potency and low cardiotoxicity from bioisosteres would be a beneficial trial.

Ibrutinib impairs IGF-1-dependent activation of intracellular Ca handling in isolated mouse ventricular myocytes

Background

The Bruton tyrosine kinase (BTK) inhibitor Ibrutinib is associated with a higher incidence of cardiotoxic side effects including heart failure (HF).

Objectives

Ibrutinib is capable of inhibiting PI3K/Akt signaling in neonatal rat ventricular cardiomyocytes when stimulated with insulin-like growth factor 1 (IGF-1). We therefore hypothesized that Ibrutinib might disrupt IGF-1-mediated activation of intracellular Ca handling in adult mouse cardiomyocytes by inhibiting PI3K/Akt signaling.

Methods

Isolated ventricular myocytes (C57BL6/J) were exposed to IGF-1 at 10 nmol/L in the presence or absence of Ibrutinib (1 µmol/L) or Acalabrutinib (10 µmol/L; cell culture for 24 ± 2 h). Intracellular Ca handling was measured by epifluorescence (Fura-2 AM) and confocal microscopy (Fluo-4 AM). Ruptured-patch whole-cell voltage-clamp was used to measure ICa. Levels of key cardiac Ca handling proteins were investigated by immunoblots.

Results

IGF-1 significantly increased Ca transient amplitudes by ∼83% as compared to vehicle treated control cells. This was associated with unaffected diastolic Ca, enhanced SR Ca loading and increased ICa. Co-treatment with Ibrutinib attenuated both the IGF-1-mediated increase in SR Ca content and in ICa. IGF-1 treated cardiomyocytes had significantly increased levels of pS473Akt/Akt and SERCA2a expression as compared to cells concomitantly treated with IGF-1 and Ibrutinib. SR Ca release (as assessed by Ca spark frequency) was unaffected by either treatment. In order to test for potential off-target effects, second generation BTK inhibitor Acalabrutinib with greater BTK selectivity and lower cardiovascular toxicity was tested for IGF1-mediated activation of intracellular Ca handling. Acalabrutinib induced similar effects on Ca handling in IGF-1 treated cultured myocytes as Ibrutinib in regard to decreased Ca transient amplitude and slowed Ca transient decay, hence implying a functional class effect of BTK inhibitors in cardiac myocytes.

Conclusions

Inhibition of BTK by Ibrutinib impairs IGF-1-dependent activation of intracellular Ca handling in adult ventricular mouse myocytes in the face of disrupted Akt signaling and absent SERCA2a upregulation.

A real-world pharmacovigilance study of FDA Adverse Event Reporting System (FAERS) events for osimertinib

Osimertinib was a third-generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which approved by the US Food and Drug Administration (FDA) in 2015 for treatment of non-small cell lung cancer (NSCLC). Our study was to explore the adverse events (AEs) caused by osimertinib through data mining of the US FDA Adverse Event Reporting System (FAERS), and provide reference for clinical safety. Data of osimertinib were collected from the FAERS database covering the period from first quarter of 2016 to the fourth quarter of 2021. Disproportionality analyses was employed to quantify the associated AE signals of osimertinib and detect the risk signals from the data in the FAERS database. Reporting odds ratio (ROR) was used to detect the risk signals from the data in the FAERS database. The definition relied on system organ class (SOCs) and preferred terms (PTs) by the Medical Dictionary for Regulatory Activities (MedDRA). Totally, 9,704,33 reports were collected from the FAERS database, 10,804 reports of osimertinib were identified as the 'primary suspected (PS)' AEs. Osimertinib induced AEs occurred in 27 organ systems. 68 significant disproportionality PTs satisfying with the four algorithms were retained at the same time. Unexpected significant AEs such as scrotal volvulus, hepatic function abnormal, venous thromboembolisms might also occur. The median onset time of osimertinib-associated AEs was 58 days (interquartile range [IQR] 14-212 days), and the majority of the AEs occurred within the first 30 days after osimertinib initiation. Our study found significant new AEs signals of osimertinib and might provide support for clinical monitoring and risk identification of osimertinib.

Review of Hydroxychloroquine Cardiotoxicity: Lessons From the COVID-19 Pandemic

Purpose of Review

The coronavirus disease 2019 (COVID-19) pandemic has popularized the usage of hydroxychloroquine and chloroquine (HCQ/CQ) as treatments for COVID-19. Previously used as anti-malarial and now commonly used in rheumatologic conditions, preliminary in vitro studies have demonstrated these medications also have anti-viral properties. Retinopathy and neuromyopathy are well recognized complications of using these treatments; however, cardiotoxicity is under-recognized. This review will discuss the implications and cardiotoxicity of HCQ/CQ, their mechanisms of action, and their utility in COVID-19.

Recent Findings

Early clinical trials demonstrated a modest benefit of HCQ in COVID-19, causing a push for the usage of it. However, further large multi-center randomized control centers, demonstrated no benefit, and even a trend towards worse outcomes. The predominant cardiac complication observed with HCQ in COVID-19 was cardiac arrhythmias and prolonging of the QT interval. However, with chronic usage of HCQ/CQ, the development of heart failure (HF) and cardiomyopathy (CM) can occur.

Summary

Although, most adverse cardiac events related to HCQ/CQ usage in COVID-19 were secondary to conduction disorders given the short duration of treatment, HCQ/CQ can cause CM and HF, with chronic usage. Given the insufficient evidence, HCQ/CQ usage in COVID-19 is not routinely recommended, especially with novel therapies now being developed and used. Additionally, usage of HCQ/CQ should prompt initial cardiac evaluation with ECG, and yearly monitoring, with consideration for advanced imaging if clinically warranted. The diagnosis of HCQ/CQ cardiomyopathy is important, as prompt cessation can allow for recovery when these changes are still reversible.

Development of New Thiophene-Containing Triaryl Pyrazoline Derivatives as PI3Kγ Inhibitors

A series of new thiophene-containing triaryl pyrazoline derivatives, 3a–3t, were synthesized and evaluated regarding PI3K inhibition activity and anti-tumor potency based on a trial of introducing significant moieties, including pyrazoline and thiophene, and simplifying the parallel ring structures. Most of the tested compounds indicated potent PI3K inhibitory potency, with this series of compounds showing more potency for PI3Kγ than PI3Kα. The top hit 3s seemed more potent than the positive control LY294002 on inhibiting PI3Kγ (IC₅₀ values: 0.066 μM versus 0.777 μM) and more selective from PI3Kα (Index values: 645 versus 1.74). It could be inferred that the combination of para- and meta-, as well as the modification of the electron-donating moieties, led to the improvement in potency. The anti-proliferation inhibitory activity and the enzymatic inhibition potency indicated consistent tendencies. The top hit 3s could inhibit the phosphorylation of Akt by inhibiting PI3K through the PI3K-Akt-mTOR pathway. The molecular docking simulation indicated that the binding pattern of 3s into PI3Kγ was preferable than that of PI3Kα, with more hydrogen bond, more π-involved interactions, and fewer π-sulfur interactions. The information in this work is referable for the further development of selective inhibitors for specific isoforms of PI3K.

Osimertinib induced cardiac failure and QT-prolongation in a patient with advanced pulmonary adenocarcinoma

INTRODUCTION

Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR) used for the treatment of non-small cell lung cancer (NSCLC) presenting an EGFR mutation. Although Osimertinib has a better safety profile compared to older EGFR-TKIs and although adverse events (AEs) are described in literature, recently the relationship between Osimertinib therapy and cardiotoxicity is gaining attention.

CASE REPORT

A 79-years old woman, with a history of lung adenocarcinoma on treatment with Osimertinib since 2019, was recovered in our department because of acute respiratory failure and acute heart failure with QT prolongation. The patient's history included hypertension, type 2 diabetes, breast carcinoma, Tuberculosis.

MANAGEMENT AND OUTCOME

The patient discontinued Osimertinib therapy and we treated her with diuretics, ß-blocker, and oxygen. After an initial improvement, the heart failure worsened further, and the therapy had to be increased. We ruled out other respiratory causes of heart failure and cardiological causes of QT prolongation. After stable clinical improvement, the patient underwent coronary artery disease which was negative. Therefore, the most likely cause of acute heart disease was Osimertinib therapy.

DISCUSSION

This is a rare case of concomitant QT prolongation and congestive heart failure induced by Osimertinib therapy. The cause of cardiotoxicity probably depends on factors related to the action of the drug and patient specific factors. The cardiotoxic risk in these patients seems underestimated and cardiotoxicity induced by new anticancer treatments is increasing in importance. Cardiac monitoring is recommended in neoplastic patients receiving Osimertinib therapy with cardiological risk factors.

Pharmacological and cell-specific genetic PI3Kα inhibition worsens cardiac remodeling after myocardial infarction

BACKGROUND

PI3Kα (Phosphoinositide 3-kinase α) regulates multiple downstream signaling pathways controlling cell survival, growth, and proliferation and is an attractive therapeutic target in cancer and obesity. The clinically-approved PI3Kα inhibitor, BYL719, is in further clinical trials for cancer and overgrowth syndrome. However, the potential impact of PI3Kα inhibition on the heart and following myocardial infarction (MI) is unclear. We aim to determine whether PI3Kα inhibition affects cardiac physiology and post-MI remodeling and to elucidate the underlying molecular mechanisms.

METHODS AND RESULTS

Wildtype (WT) 12-wk old male mice receiving BYL719 (daily, p.o.) for 10 days showed reduction in left ventricular longitudinal strain with normal ejection fraction, weight loss, mild cardiac atrophy, body composition alteration, and prolonged QTC interval. RNASeq analysis showed gene expression changes in multiple pathways including extracellular matrix remodeling and signaling complexes. After MI, both p110α and phospho-Akt protein levels were increased in human and mouse hearts. Pharmacological PI3Kα inhibition aggravated cardiac dysfunction and resulted in adverse post-MI remodeling, with increased apoptosis, elevated inflammation, suppressed hypertrophy, decreased coronary blood vessel density, and inhibited Akt/GSK3β/eNOS signaling. Selective genetic ablation of PI3Kα in endothelial cells was associated with worsened post-MI cardiac function and reduced coronary blood vessel density. In vitro, BYL719 suppressed Akt/eNOS activation, cell viability, proliferation, and angiogenic sprouting in coronary and human umbilical vein endothelial cells. Cardiomyocyte-specific genetic PI3Kα ablation resulted in mild cardiac systolic dysfunction at baseline. After MI, cardiac function markedly deteriorated with increased mortality concordant with greater apoptosis and reduced hypertrophy. In isolated adult mouse cardiomyocytes, BYL719 decreased hypoxia-associated activation of Akt/GSK3β signaling and cell survival.

CONCLUSIONS

PI3Kα is required for cell survival (endothelial cells and cardiomyocytes) hypertrophic response, and angiogenesis to maintain cardiac function after MI. Therefore, PI3Kα inhibition that is used as anti-cancer treatment, can be cardiotoxic, especially after MI.

Cardiac Safety of Kinase Inhibitors - Improving Understanding and Prediction of Liabilities in Drug Discovery Using Human Stem Cell-Derived Models

Many small molecule kinase inhibitors (SMKIs) used to fight cancer have been associated with cardiotoxicity in the clinic. Therefore, preventing their failure in clinical development is a priority for preclinical discovery. Our study focused on the integration and concurrent measurement of ATP, apoptosis dynamics and functional cardiac indexes in human stem cell-derived cardiomyocytes (hSC-CMs) to provide further insights into molecular determinants of compromised cardiac function. Ten out of the fourteen tested SMKIs resulted in a biologically relevant decrease in either beating rate or base impedance (cell number index), illustrating cardiotoxicity as one of the major safety liabilities of SMKIs, in particular of those involved in the PI3K–AKT pathway. Pearson's correlation analysis indicated a good correlation between the different read-outs of functional importance. Therefore, measurement of ATP concentrations and apoptosis in vitro could provide important insight into mechanisms of cardiotoxicity. Detailed investigation of the cellular signals facilitated multi-parameter evaluation allowing integrative assessment of cardiomyocyte behavior. The resulting correlation can be used as a tool to highlight changes in cardiac function and potentially to categorize drugs based on their mechanisms of action.

Case Report: QT Prolongation and Abortive Sudden Death Observed in an 85-Year-Old Female Patient With Advanced Lung Cancer Treated With Tyrosine Kinase Inhibitor Osimertinib

Cardiac arrest occurred in an 85-year-old female administered osimertinib for advanced lung cancer expressing epidermal growth factor receptor (EGFR) mutations. Electrocardiogram (ECG) recorded at recurrence of spontaneous circulation showed sinus rhythm associated with mild QT prolongation (QTc = 455 ms) to which silent myocardial ischemia and coadministration of itraconazole and herbal drug causing hypokalemia (2.1 mEq/L) may have contributed. Discontinuation of osimertinib, itraconazole and herbal drug, potassium supplementation and percutaneous coronary intervention alleviated QT prolongation (QTc = 432 ms). Osimertinib is the third-generation tyrosine kinase inhibitor lengthening QT interval, and careful monitoring of ECG, serum potassium and drugs coadministered during chemotherapy including osimertinib are highly required.