Immune checkpoint inhibitors in the management of malignancies in transplant recipients

Frontiers and Controversies in De Novo Gastrointestinal Tumors After Organ Transplantation: Current Progress and Future Directions

The increasing success of organ transplantation has significantly improved survival for patients with end-stage diseases, yet it introduces a complex dilemma: the elevated risk for the development of de novo gastrointestinal (GI) tumors. The sustained immunosuppression required to maintain graft function paradoxically undermines the body's natural defenses against cancer, leading to a higher incidence, aggressive progression, and atypical presentations of GI tumors among transplant recipients compared with the general population. This presents a pressing challenge: balancing the dual imperatives of preventing graft rejection and effectively managing malignancies. Current treatment paradigms, including surgical approaches, chemotherapy, radiation therapy, and the emerging role of immunotherapy, are fraught with complexities due to the altered immune landscape in these patients. This review underscores the critical need to understand the multifaceted relationship between post-transplantation immunosuppression and tumorigenesis, providing a comprehensive exploration of epidemiologic shifts, pathophysiologic insights, and the intricacies of the tumor microenvironment in this unique patient population. Understanding and managing GI tumors in transplant recipients is not only a clinical challenge, but also a necessary frontier in transplant oncology, promising to refine therapeutic strategies and improve the longevity and quality of life for this growing patient cohort.

Anti-PD-1 immunotherapy for the treatment of metastatic urothelial carcinoma in a kidney transplant recipient: a case report

BACKGROUND

Immune checkpoint inhibitor (ICI) therapy has been widely investigated in urothelial carcinoma; however, the utility of ICI therapy in the treatment of organ transplant recipients with metastatic urothelial carcinoma (mUC) is unclear. We herein report the first case of a first-line anti-programmed cell death-1 (anti-PD-1) monotherapy for a kidney transplant patient with mUC.

CASE PRESENTATION

A 71-year-old woman who received a kidney transplant in 2003 was diagnosed with urothelial carcinoma in 2018. After operation of the tumor, the patient developed local recurrence at the site of the right kidney and bladder and multiple distant metastases in May 2020. Considering the intolerance of chemotherapy and high tumor mutation burden, we administered the anti-PD-1 agent tislelizumab (200 mg every three weeks). Partial response was achieved after two cycles of therapy and sustained until 18th cycles. There were no signs of kidney graft rejection. The immunotherapy was temporarily stopped after the 18th course because of a suspicious immune-related pneumonitis and was continued in December 2021.

CONCLUSIONS

This case demonstrates the feasibility of safely achieving stable cancer control in a kidney transplant patient with mUC without encountering graft rejection by using single-agent anti-PD-1 treatment.

Immune Checkpoint Inhibitors and Their Cardiovascular Adverse Effects

Immune checkpoint inhibitors (ICIs) have reshaped and have become a well-established treatment modality for multiple advanced-stage malignancies. ICIs block the immune system regulatory checkpoints, namely CTLA-4 and PD-1/PDL1, which provokes excess immune response against self-antigens. Immune modulation with ICIs can result in diverse immune-related adverse events targeting organ systems. Several cases of ICI-related cardiotoxicity were reported, while the actual incidence was likely underestimated due to heterogeneous clinical presentation. These include, but are not limited to, myocarditis, pericarditis, atherosclerosis, and arrhythmia. EKG, Troponin, Echocardiogram (TTE), and Cardiac MRI (CMRI) are indispensable diagnostic tools to aid in the management of cardiac adverse effects. Herein, we review the ICI-mediated cardiovascular adverse events, diagnosis, treatment strategies, and reintroduction of ICIs post-cardiotoxicity.

A Review of the Pharmacokinetic Characteristics of Immune Checkpoint Inhibitors and Their Clinical Impact Factors

Immune checkpoint inhibitors (ICIs) have been shown to be significant in improving the overall survival rate in certain malignancies with poor prognoses. However, only 20-40% of patients achieve long-term benefits, highlighting the relevance of the factors that influence the treatment, which can help clinicians improve their results and guide the development of new immune checkpoint therapies. In this study, the current pharmacokinetic aspects associated with the ICIs and the factors influencing clinical efficacy were characterised, including in terms of drug metabolism, drug clearance, hormonal effects and immunosuppressive effects.

Intratumoral immunotherapy with anti-PD-1 and TLR9 agonist induces systemic antitumor immunity without accelerating rejection of cardiac allografts

Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) blockades, have revolutionized the field of cancer immunotherapy. However, there is a growing concern whether PD-1 inhibitors can be administered safely to transplant recipients with advanced cancer, as the T cells activated by checkpoint inhibitors may become reactive not only toward tumor antigens but also toward donor alloantigen, thereby resulting in allograft rejection. Here, immunotherapy with anti-PD-1/toll like receptor 9 agonist was administered to C57BL/6 mice bearing a cardiac allograft that were receiving maintenance immunosuppression or a PI4KIIIβ inhibitor-based tolerogenic regimen. Intratumoral (i.t.), but not systemic, immunotherapy promoted potent anti-tumor responses, but did not accelerate allograft rejection. This effect was associated with a pro-immunogenic effect induced by i.t. immunotherapy resulting in systemic cellular and humoral immune anti-tumor responses. Furthermore, when the tumor and cardiac allograft shared major histocompatibility complex (MHC) antigens, i.t. immunotherapy promoted immune responses directed against tumor and the cardiac allograft resulting in allograft rejection. The anti-tumor effect was compromised by maintenance immunosuppression with cyclosporin A, indicating that an optimal balance between enhanced anti-tumor immunity and decreased transplant immunoreactivity is critical. A clinically relevant approach could be to temporarily withdraw maintenance immunosuppression and/or replace it with a PI4KIIIβ inhibitor-based tolerance-inducing regimen to allow for effective immunotherapy to take place.

Management of de-novo urothelial carcinoma in transplanted patients

PURPOSE OF REVIEW

The aim of this article is to review incidence, risk factors, and optimal management of de-novo urothelial carcinoma in transplant recipients.

RECENT FINDINGS

There is a two to three-fold increased risk for de-novo malignant tumors after solid-organ transplantation, but there is currently no consensus regarding optimal management of de-novo urothelial carcinoma in transplanted patients. Known risk factors include polyomavirus BK, aristolochic acid, and smoking. Data suggest a higher rate of high-grade tumors, as well as predominantly higher stage at primary diagnosis, for both NMIBC and muscle-invasive bladder cancer (MIBC). Treatment for NMIBC includes TURB, mitomycin, and Bacille de Calmette-Guérin instillation with special concern to the immunosuppressive regime. Treatment of MIBC or advanced urothelial carcinoma includes radical cystectomy with chemotherapy if the patient is eligible. A screening should be performed in all transplant recipients, to allow early diagnosis.

SUMMARY

De-novo urothelial carcinoma in transplant recipients is more frequent than in the general population and these tumors were more likely to be high-grade tumors and diagnosed at an advanced stage. There is very little information available on the optimal treatment for these patients. However, aggressive treatment and a strict management according the given recommendations are of the utmost importance.

Cutaneous immune-related adverse events to checkpoint inhibitors

The development of immunotherapy has led to a paradigm shift in the treatment of both solid and hematologic malignancies. As immunomodulatory therapies are employed with increasing frequency, a greater number of immune-related adverse reactions are being reported, and the majority of these involve the skin. As a result, dermatologists are increasingly becoming involved in the management of these cutaneous adverse reactions-often providing critical recommendations regarding ongoing cancer treatment. Cutaneous immune-related adverse reactions can vary significantly from patient to patient, making early recognition and timely intervention imperative to mitigate associated morbidity and potential treatment interruption. Although there is considerable overlap in the cutaneous adverse events caused by these immune checkpoint inhibitors, specific eruptions are characteristically associated with particular checkpoint inhibitors. In addition, a patient's comorbidities or immune status can play a significant role in the presentation and management of such adverse reactions. This review characterizes and provides management guidelines for the various cutaneous toxicities associated with checkpoint inhibitor therapy, including CTLA-4 inhibitors, PD-1 inhibitors, and PD-L1 inhibitors. © 2020 Elsevier Inc. All rights reserved.

Programmed Cell Death 1 (PD-1) Inhibitors in Renal Transplant Patients with Advanced Cancer: A Double-Edged Sword?

Given advancements in cancer immunity, cancer treatment has gained breakthrough developments. Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) inhibitors, are the most promising drugs in the field and have been approved to treat various types of cancer, such as metastatic melanoma, head and neck squamous cell carcinoma, and urothelial carcinoma. However, whether PD-1 inhibitors should be administered to renal transplant patients with advanced cancer remains unclear because the T-cells produced after administration of these inhibitors act against not only tumor antigens but also donor alloantigens. Thus, the use of PD-1 inhibitors in kidney-transplanted patients with advanced cancer is limited on account of the high risk of graft failure due to acute rejection. Hence, finding optimal treatment regimens to enhance the tumor-specific T-cell response and decrease T-cell-mediated alloreactivity after administration of a PD-1 inhibitor is necessary. Thus far, no recommendations for the use of PD-1 inhibitors to treat cancer in renal transplant patients are yet available, and very few cases reporting kidney-transplanted patients treated with PD-1 inhibitors are available in the literature. Therefore, in this work, we review the published cases and suggest feasible approaches for renal transplant patients with advanced malignancy treated by a PD-1 inhibitor. Of the 22 cases we obtained, four patients maintained intact grafts without tumor progression after treatment with a PD-1 inhibitor. Among these patients, one maintained steroid dose before initiation of anti-PD1, two received immunosuppressive regimens with low-dose steroid and calcineurin inhibitor (CNI)-elimination with sirolimus before initiation of anti-PD-1 therapy, and one received combined anti-PD-1, anti-vascular endothelial growth factor (VEGF), and chemotherapy with unchanged immunosuppressive regimens. mammalian target of rapamycin (mTOR) inhibitors and anti-VEGF may act as regulators of tumor-specific and allogenic T-cells. However, more studies are necessary to explore the optimal therapy and ensure the safety and efficacy of PD-1 inhibitors in kidney-transplanted patients.