Vascular events with immune checkpoint inhibitors in melanoma or non-small cell lung cancer: A systematic review and meta-analysis

Thrombotic events associated with immune checkpoint inhibitors and novel antithrombotic strategies to mitigate bleeding risk

Although immunotherapy is expanding treatment options for cancer patients, the prognosis of advanced cancer remains poor, and these patients must contend with both cancers and cancer-related thrombotic events. In particular, immune checkpoint inhibitors are associated with an increased risk of atherosclerotic thrombotic events. Given the fundamental role of platelets in atherothrombosis, co-administration of antiplatelet agents is always indicated. Platelets are also involved in all steps of cancer progression. Classical antithrombotic drugs can cause inevitable hemorrhagic side effects due to blocking integrin β3 bidirectional signaling, which regulates simultaneously thrombosis and hemostasis. Meanwhile, many promising new targets are emerging with minimal bleeding risk and desirable anti-tumor effects. This review will focus on the issue of thrombosis during immune checkpoint inhibitor treatment and the role of platelet activation in cancer progression as well as explore the mechanisms by which novel antiplatelet therapies may exert both antithrombotic and antitumor effects without excessive bleeding risk.

Immune checkpoint inhibitor-associated cardiovascular toxicities: A review

Immune checkpoint inhibitors (ICIs) have revolutionary effects on therapeutic strategies for multiple malignancies. Their efficacy depends on their ability to reactivate the host immune system to fight cancer cells. However, adverse reactions to ICIs are common and involve several organs, limiting their use in clinical practice. Although the incidence of cardiovascular toxicity is relatively low, it is associated with serious consequences and high mortality rates. The primary cardiovascular toxicities include myocarditis, pericarditis, Takotsubo syndrome, arrhythmia, vasculitis, acute coronary syndrome, and venous thromboembolism. Currently, the mechanism underlying ICI-associated cardiovascular toxicity remains unclear and underexplored. The diagnosis and monitoring of ICI-associated cardiovascular toxicities mainly include the following indicators: symptoms, signs, laboratory examination, electrocardiography, imaging, and pathology. Treatments are based on the grade of cardiovascular toxicity and mainly include drug withdrawal, corticosteroid therapy, immunosuppressants, and conventional cardiac treatment. This review focuses on the incidence, underlying mechanisms, clinical manifestations, diagnoses, and treatment strategies.

Thrombotic risk of platinum combination chemotherapy with and without immune checkpoint inhibitors for advanced non-small cell lung cancer: a nationwide inpatient database study

OBJECTIVES

To determine the associated thromboembolism risk with adding immune checkpoint inhibitors (ICI) to platinum combination chemotherapy compared with platinum combination chemotherapy alone in patients with advanced non-small cell lung cancer.

MATERIALS AND METHODS

This study identified 75,807 patients with advanced non-small cell lung cancer from the Japanese Diagnosis Procedure Combination database who started platinum combination chemotherapy between July 2010 and March 2021. The incidence of venous thromboembolism (VTE), arterial thromboembolism (ATE), and all-cause mortality within 6 months after commencing platinum combination chemotherapy was compared between patients receiving chemotherapy with ICI (ICI group, n = 7,177) and without ICI (non-ICI group, n = 37,903). Survival time analysis was performed using the overlap weighting method with propensity scores to adjust for background factors. The subdistribution hazard ratio for developing thromboembolism was calculated using the Fine-Gray model with death as a competing risk. The hazard ratio for all-cause mortality was also calculated using the Cox proportional hazards model.

RESULTS

Overall, VTE and ATE occurred in 761 (1.0%) and 389 (0.51%) patients, respectively; mortality was 11.7%. Propensity score overlap weighting demonstrated that the subdistribution hazard ratio (95% confidence interval) for VTE and ATE in the ICI group was 1.27 (1.01-1.60) and 0.96 (0.67-1.36), respectively, compared with the non-ICI group. The mortality hazard ratio in the ICI group was 0.68 (0.62-0.74).

CONCLUSION

The addition of ICI to platinum combination therapy was associated with a higher risk of VTE compared with platinum combination therapy alone, while the risk of ATE might be comparable.

Adjuvant therapy for stage II melanoma: the need for further studies

Immunotherapy with checkpoint inhibitors has revolutionised the outcomes for melanoma patients. In the metastatic setting, patients treated with nivolumab and ipilimumab have an expected 5-year survival of> 50%. For patients with resected high-risk stage III disease, adjuvant pembrolizumab, nivolumab or dabrafenib and trametinib are associated with a significant improvement in both relapse-free survival (RFS) and distant metastasis-free survival (DMFS). More recently neoadjuvant immunotherapy has shown very promising outcomes in patients with clinically detectable nodal disease and is likely to become a new standard of care. For stage IIB/C disease, two pivotal adjuvant trials of pembrolizumab and nivolumab have also reported a significant improvement in both RFS and DMFS. However, the absolute benefit is low and there are concerns about the risk of severe toxicities as well as long-term morbidity from endocrine toxicity. Ongoing registration phase III trials are currently evaluating newer immunotherapy combinations and the role of BRAF/MEK-directed targeted therapy for stage II melanoma. However, our ability to personalise therapy based on molecular risk stratification has lagged behind the development of novel immune therapies. There is a critical need to evaluate the use of tissue and blood-based biomarkers, to better select patients that will recur and avoid unnecessary treatment for the majority of patients cured by surgery alone.

Causes of death among patients with cutaneous melanoma: a US population-based study

Research on mortality outcomes and non-cancer-related causes of death in patients with cutaneous melanoma (CM) remains limited. This study aimed to identify the prevalence of non-cancer-related deaths following CM diagnosis. The data of 224,624 patients diagnosed with malignant CM in the United States between 2000 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. We stratified our cohort based on their melanoma stage at diagnosis and further calculated standardized mortality ratios (SMRs) for each cause of death, comparing their relative risk to that of the general US population. The total number of fatalities among melanoma patients was 60,110, representing 26.8% of the total cases. The percentage of deaths is directly proportional to the disease stage, reaching 80% in distant melanoma. The highest fatalities among the localized melanoma group (25,332; 60.5%) occurred from non-cancer causes, followed by melanoma-attributable deaths (10,817; 25.8%). Conversely, melanoma is the leading cause of death in regional and distant melanoma cohorts. Cardiovascular and cerebrovascular diseases were the most prevalent non-cancer causes of death among the three disease-stage cohorts. Compared to the general population, we did not observe an increased risk of death due to non-cancer causes in the localized CM cohort, while patients diagnosed with regional and distant CMs had a statistically significant higher risk of death from all the reported major causes of death.

Immune Checkpoint Inhibitors-Associated Thrombosis: Incidence, Risk Factors and Management

Immune checkpoint inhibitors (ICIs) target programmed cell death (PD) 1 receptor and its ligand PD-L1, and have become an integral part of treatment regimens in many cancers including lung cancer, renal cell carcinoma, melanoma, and more. Cancer is associated with a significantly increased risk of venous thromboembolism compared to non-cancer patients, and the risks increase further with anticancer therapies including ICIs. Cancer-associated thrombosis can lead to hospitalizations, delayed cancer treatment, and mortality. While thrombosis was not reported as a major complication in initial clinical trials leading to the approval of ICIs, emerging evidence from post-marketing studies revealed concerning risks of thrombosis in patients receiving ICIs. However, results remained heterogenous given differences in study designs and populations. Recent studies also showed that C-reactive protein dynamics might be an easily accessible biomarker for thrombosis and disease response in this population. In addition, early findings indicated that a commonly used anticoagulant for cancer-associated thrombosis, factor Xa inhibitors, might have potential synergistic antitumor effects when combined with ICIs. Herein we will review the current literature on the incidence, risk factors, and management of thrombosis in patients with cancer receiving ICIs. We aim to provide valuable information for clinicians in managing these patients.

Clinical impact of venous thromboembolism in non-small cell lung cancer patients receiving immunotherapy

BACKGROUND

Prospective investigation on cancer-associated venous thromboembolism (VTE) in non-small cell lung cancer (NSCLC) during treatment with immune checkpoint inhibitors (ICIs) is lacking.

PATIENTS AND METHODS

A prospective real-world study using combined computed tomography venography and pulmonary angiography (CTVPA) to screen patients with NSCLC for VTE (cohort A). A retrospective multicenter cohort without additional screening with CTVPA was included as control (cohort B). A model with VTE as a time-dependent event using competing risk analysis model with death as a competing event was used to evaluate outcomes and differences in cumulative VTE incidences.

RESULTS

Cohort A (n = 146) and cohort B (n = 426) had median follow-up for VTE of 16.5 months (IQR 6.7-35.6). Cumulative VTE events at 1, 3, 6, and 12 months were 7.5 %, 9.6 %, 13.0 %, 14.4 % for cohort A and 1.9 %, 3.8 %, 4.9 %, 5.6 % for cohort B with SHR 2.42 (CI 95 % 1.37-4.27) p = 0.0024. Recurrent VTE comprised 52 % and 37 %, respectively. In multivariate overall survival analysis, VTE was significantly associated with impaired OS (HR 2.12 CI 95 % [1.49-3.03], p < 0.0001). Risk factors for VTE comprised prior VTE and ICI administered in first line.

CONCLUSION

Cumulative VTE incidence in NSCLC patients following palliative ICI may be significantly higher than reported in randomised clinical trials and retrospective real-world reports. VTE development during ICI impair OS significantly. Thus, more focus on VTE during ICI is warranted to optimise both prevention and management of VTE. Whether there is a causal relationship between VTE and ICI remains to be explored.

Associations Between Immune-Related Venous Thromboembolism and Efficacy of Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

This study aims to summarize the available data and determine if the presence of venous thromboembolism (VTE) immune-related adverse event (irAE) in patients with immune checkpoint inhibitor (ICI) therapy is associated with improved treatment efficacy and clinical outcomes, which in turn was used to help optimize patient selection for anticoagulation therapy and inform rational treatment strategies for overcoming the mechanisms of ICI resistance. PubMed, Embase, Web of Science, and Cochrane Library were searched up to March 18, 2023, for studies assessing the relationship between VTE irAE development during ICI therapy and cancer outcomes. Seven primary articles with a total of 4437 patients were included in the overall survival (OS) meta-analysis. Patients with VTE had a significant increase in overall mortality compared to patients without VTE in adjusted hazard ratios (HRs 1.36, 95% confidence interval [CI] 1.06-1.75, P  =  .02). In the studies where immortal time bias (ITB) was accounted for, patients with VTE irAE also had poor OS than those without. HR and the corresponding 95% CI values in the non-ITB group were 2.53 (1.75-3.66, P < .00001) with low heterogeneity (P  =  .17, I2  =  48%) and 1.21 (1.06-1.37, P  =  .004) in the ITB group with no heterogeneity (P  =  .95, I2  =  0%), respectively. Despite the heterogeneity identified, the evidence does suggest that VTE irAE occurrence could be served as a prognostic indicator, with higher frequencies of occurrence associated with poorer OS. However, the fundamental role of this association with clinical consequences should be further investigated in large cohorts and clinical trials.

Risk of Thromboembolic Events in Cancer Patients Treated with Immune Checkpoint Inhibitors: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

 The association between immune checkpoint inhibitors (ICIs) and thromboembolic events (TEEs) remains controversial.

OBJECTIVE

 The goal of this study was to assess the risk of major TEEs associated with ICIs.

METHODS

 We explored ICI-related TEEs in randomized controlled trials available in ClinicalTrials.gov and electronic databases up to June 30, 2021. Meta-analysis was performed by using Peto odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

 A total of 61 studies were included. Patients treated with ICIs had a similar risk of venous thromboembolism (VTE) but a significantly increased risk of arterial thromboembolism (ATE) (Peto OR: 1.58 [95% CI: 1.21-2.06]) compared with non-ICI regimens. Stratified by different regimens, only PD-L1 (programmed cell death ligand 1) inhibitors showed a significant increase in ATE (Peto OR: 2.07 [95% CI: 1.26-3.38]). The incidence of VTE was higher in PD-1/PD-L1 inhibitor and CTLA-4 (cytotoxic T lymphocyte antigen 4) inhibitor combination therapies compared with monotherapies (Peto OR: 2.23 [95% CI: 1.47-3.37]). Stratified by tumor, for pulmonary embolism (PE) and cerebral ATE, the statistically significant results were only seen in lung cancer patients (Peto OR: 1.42 [95% CI: 1.02-1.97]; Peto OR: 2.10 [1.07-4.12]), and for myocardial infarction, the statistically significant result was only seen in other tumor types (Peto OR: 2.66 [95% CI: 1.68-4.20], p < 0.0001).

CONCLUSION

 There was no significant increase in the overall risk of VTE in patients treated with ICIs; however, special attention should be given to the risk of VTE in PD-1/PD-L1 inhibitor and CTLA-4 inhibitor combination therapy and PE in lung cancer patients. PD-L1 inhibitors were associated with a significant increase in ATE.