Immune checkpoint blockade for organ transplant patients with advanced cancer: how far can we go?

Inhibition of interferon regulatory factor 4 orchestrates T cell dysfunction, extending mouse cardiac allograft survival

BACKGROUND

T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction.

METHODS

A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of MAPK and mammalian target of Rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models.

RESULTS

In vitro, blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg-1·day-1) and Rapamycin (0.1 mg·kg-1·day-1) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression.

CONCLUSIONS

Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.

Primary prophylaxis with mTOR inhibitor enhances T cell effector function and prevents heart transplant rejection during talimogene laherparepvec therapy of squamous cell carcinoma

The application of mammalian target of rapamycin inhibition (mTORi) as primary prophylactic therapy to optimize T cell effector function while preserving allograft tolerance remains challenging. Here, we present a comprehensive two-step therapeutic approach in a male patient with metastatic cutaneous squamous cell carcinoma and heart transplantation followed with concomitant longitudinal analysis of systemic immunologic changes. In the first step, calcineurin inhibitor/ mycophenolic acid is replaced by the mTORi everolimus to achieve an improved effector T cell status with increased cytotoxic activity (perforin, granzyme), enhanced proliferation (Ki67) and upregulated activation markers (CD38, CD69). In the second step, talimogene laherparepvec (T-VEC) injection further enhances effector function by switching CD4 and CD8 cells from central memory to effector memory profiles, enhancing Th1 responses, and boosting cytotoxic and proliferative activities. In addition, cytokine release (IL-6, IL-18, sCD25, CCL-2, CCL-4) is enhanced and the frequency of circulating regulatory T cells is increased. Notably, no histologic signs of allograft rejection are observed in consecutive end-myocardial biopsies. These findings provide valuable insights into the dynamics of T cell activation and differentiation and suggest that timely initiation of mTORi-based primary prophylaxis may provide a dual benefit of revitalizing T cell function while maintaining allograft tolerance.

Research progress on CD8+ T cell immune regulation in allogenic transplantation

With advances in tissue typing, organ preservation techniques, and clinical surgery, organ transplantation has gained popularity as a treatment option for various end-stage diseases. Allogeneic transplantation has been widely adopted and extensively researched in clinical practice. Despite significant breakthroughs and progress in immunosuppression, this procedure is still associated with several adverse reactions and complications. Therefore, there is a continuing need to explore new immunological approaches to provide fresh insights and guidance for clinical transplantation. CD8+ T cells, traditionally known for their cytotoxic function and their ability to recognize transplanted organs as "non-self" entities, display cytotoxicity. However, recent studies have unveiled that CD8+ T cells have various subtypes and functions that extend beyond conventional cytotoxicity. These CD8+ T cell subtypes include Effector CD8+ T cells, Memory CD8+ T cells, and CD8Treg cells. This review examines the immune regulatory mechanisms of CD8+ T cells in allogeneic transplantation and discusses the potential applications of CD8+ T cells in treating tumors in transplant recipients who are receiving immunosuppressive therapy. These findings offer theoretical guidance for reducing post-transplant rejection reactions and improving adverse prognoses, offering new hope for improved clinical survival rate.

Transplant Oncology: An Emerging Discipline of Cancer Treatment

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients' survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Immunotherapy and Liver Transplantation: A Narrative Review of Basic and Clinical Data

Immune checkpoint inhibitors (ICIs) have improved the management of patients with intermediate- and advanced-stage HCC, even making some of them potential candidates for liver transplantation. However, acute rejection has been observed after ICI therapy, challenging its safety in transplant settings. We summarize the key basic impact of immune checkpoints on HCC and liver transplantation. We analyze the available case reports and case series on the use of ICI therapy prior to and after liver transplantation. A three-month washout period is desirable between ICI therapy and liver transplantation to reduce the risk of acute rejection. Whenever possible, ICIs should be avoided after liver transplantation, and especially so early after a transplant. Globally, more robust prospective data in the field are required.

Surgery in the Era of Immunotherapy for Advanced Head and Neck Non-melanoma Skin Cancer

PURPOSE OF REVIEW

Surgery remains the mainstay of treatment for non-melanoma skin cancer (NMSC). Immunotherapy (IO) has emerged as an alternative option. This review provides a contemporary summary of how to incorporate IO into the management of advanced NMSC. Evidence-based outcomes and recent clinical trials are provided with emphasis on the three most common NMSC diagnoses: cutaneous squamous cell carcinoma (cSCC), basal cell carcinoma (BCC), and merkel cell carcinoma (MCC).

RECENT FINDINGS

Surgical resection while preserving form and function remains the standard of care for the majority of NMSCs. In recalcitrant cases failing traditional surgery and/or primary radiation, patient ineligible for such treatments, or unresectable disease, IO has emerged as a promising alternative. In the majority of cases, it is a supplanting primary chemotherapy. Surgery remains the standard of care for NMSC. Immunotherapy has emerged as an alternative option for non-surgical candidates and as a neoadjuvant means to minimize morbidity.

Spontaneous regression of a metastatic carcinoma transmitted by a kidney graft

Transmission of a malignancy from a donor's organ to the recipient of the graft is a rare event, though it is a severe complication that can result in a poor outcome. Usually, immunosuppressive therapy is discontinued and the allograft is removed. However, treatment of patients with the disseminated cancers implies that after the graft removal and cessation of the immunosuppression, radiotherapy, chemotherapy, or immunotherapy with alpha-interferon (INF-α) or interleukin-2 (IL-2) are required. The case report presents a clinical case of a transmitted kidney graft with multiple metastases (MTS) in a 31-year-old woman with the spontaneous regression of the metastatic cancer after transplantectomy and cancellation of the immunosuppressive therapy. Obviously, the determining factor is the recognition of the tumor by the effectors of the antitumor immunity due to the human leukocyte antigen (HLA) mismatch between the donor and the recipient. Therefore, cancellation of the immunosuppressive therapy in cases of transferal of a malignancy with a transplanted organ allows the effectors of the immune system to distinguish the tumor as a foreign tissue and effectively eliminate this neoplasm.

Challenges and knowledge gaps with immune checkpoint inhibitors monotherapy in the management of patients with non-small-cell lung cancer: a survey of oncologist perceptions

BACKGROUND

Immune checkpoint-inhibitors (ICIs) are changing outcomes in different cancer settings, notably for patients with non-small-cell lung cancer (NSCLC). There are, however, still important gaps of evidence for clinical practice when using these novel treatments. In this study, we assessed physicians' opinion and experience on challenges for clinical practice with ICIs monotherapy in NSCLC.

METHODS

A survey was conducted on experienced physicians treating patients with NSCLC with ICIs. Two rounds of pilot tests were carried out for validation among a group of experts. Topics under analysis were in relation to treatment of elderly populations, performance status, brain metastases, use of steroids or antibiotics, the effects of gut microbiome, autoimmune diseases, human immunodeficiency virus infection, solid organ transplants, use of anti-programmed cell death protein 1 versus anti-programmed death-ligand 1 drugs, atypical tumour responses, predictors of response, duration of treatment and a final open question on additional relevant challenges.

RESULTS

Two hundred and twenty-one answers were collected, including 106 (48%) valid answers from experts for final analysis (physicians who have treated at least 20 patients with NSCLC with ICIs). The vast majority agreed that the selected topics in this study are important challenges ahead and more evidence is needed. Moreover, predictors of response, treating brain metastasis, shorter duration of treatment, the effects of gut microbiome and concomitant use of steroids were voted the most important topics to be further addressed in prospective clinical research.

CONCLUSIONS

This survey contributed to understanding which are the main challenges for clinical practice with ICIs monotherapy in NSCLC. It can also contribute to guide further clinical research, considering the opinions and experience of those who regularly treat NSCLC patients with ICIs.

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.

American Head and Neck Society position statement on the use of PD-1 inhibitors for treatment of advanced cutaneous squamous cell carcinoma

BACKGROUND

A position statement put forth by the American Head and Neck Society (AHNS) was constructed to provide evidence-based treatment recommendations for PD-1 inhibitor use in advanced cutaneous squamous cell carcinoma (cSCC). Secondarily, we sought to identify knowledge gaps warranting further investigation.

METHODS

A literature search utilizing key terms: cutaneous squamous cell carcinoma, cutaneous cancer, checkpoint inhibitors, systemic therapy, Program Cell Death, PD-1 (PubMed, Cochrane, and Google Scholar) was carried out to generate evidence-based statements. The statements were distributed among the AHNS membership. Delphi methodology was applied to identify statements achieving 70% or greater consensus among the leadership team.

RESULTS

Twenty-six position statements achieved consensus. Knowledge gaps for future research included: impact of immunosuppression on cSCC staging and associated treatment; role of PD-1 inhibitors in immunosuppressed patients.

CONCLUSION

This comprehensive position statement put forth by the AHNS represents majority consensus by practicing head and neck surgeons throughout the country.

Immune microenvironment and therapeutic progress of recurrent hepatocellular carcinoma after liver transplantation

HCC is a highly lethal tumor, and orthotopic liver transplantation, as one of the radical treatment methods for HCC, has opened-up a new therapeutic approach for the treatment of primary liver cancer. However, tumor recurrence after liver transplantation is the main reason that affects the long-term survival of recipients. At present, the application of ICIs has brought dawn to patients with refractory HCC. However, because of the special immune tolerance state created by long-term oral immunosuppressants in patients with HCC after liver transplantation, the current focus is how to regulate the immune balance of such patients and simultaneously maximize the anti-tumor effect. This article reviews the relationship between liver cancer and immunity, immune tolerance of liver transplantation, immune microenvironment after liver transplantation for HCC, and the application of immunotherapy in the recurrence of liver transplantation for HCC.

Malignancies in adult kidney transplant candidates and recipients: current status

Posttransplant malignancies, particularly recurrent and de novo, in solid organs including kidney transplant recipients (KTRs) are a significant complication associated with substantial mortality, largely attributed to long-term immunosuppression necessary to maintain allograft tolerance. Older age at transplantation and oncogenic virus infection along with pretransplant malignancies are among the main factors contributing to the risk of cancer in this population. As the mean age of transplant candidates rises, the rate of transplant recipients with pretransplant malignancies also increases. The eligibility criteria for transplantation in patients with prior cancer have recently changed. The overall risk of posttransplant malignancies is at least double after transplantation including KTRs relative to the general population, most pronounced for skin cancers associated with UV radiation and virally-mediated tumors. The risk of renal cell carcinoma is specifically increased in the kidney transplant population. The therapy of cancer in transplant patients is associated with risk of higher toxicity, and graft rejection and/or impairment, which poses a unique challenge in the management. Reduction of immunosuppression and the use of mTOR inhibitors are common after cancer diagnosis, although optimal immunosuppression for transplant recipients with cancer remains undefined. Suboptimal cancer treatment contributing to a worse prognosis has been reported for malignancies in this population. In this article, we focus on the prevalence and outcomes of posttransplant malignancies, cancer therapy including a short overview of immunotherapy, cancer screening and prevention strategies, and immunosuppression as a cancer risk factor. The 2020/2021 recommendations of the Kidney Diseases Improving Global Outcome (KDIGO) and American Society of Transplantation (AST) for transplant candidates with a history of cancer are presented.

Novel immunosuppressive effect of FK506 by upregulation of PD-L1 via FKBP51 in heart transplantation

The calcineurin inhibitor-FK506-is a first-line immunosuppressant that regulates T-cell secretion of IL-2 and other cytokines. However, the mechanism of its protective effect on target cells and its role on tumor recurrence and interaction with anti-tumor immune checkpoint inhibitors, such as PD-L1 blocking, are still unclear. Here, in a murine heart transplantation model, we observed the upregulation of programmed death-ligand 1 (PD-L1) expression by FK506 in both dendritic cells (DCs) and allografts. Blocking PD-L1 during FK506 treatment increased IFN-γ and TNF-α expression, enhanced CD4⁺ and CD8⁺ T-cell proliferation, and suppressed Treg differentiation. Moreover, PD-L1 decreased T-cell infiltration and induced T cell apoptosis in both the spleen and graft. PD-L1 was not only required in FK506-mediated immunosuppression but also upregulated by FK506. Treatment with SAFit2, a FKBP51 selective inhibitor, reduced the expression of PD-L1 on DCs and the grafts and interfered with the immunosuppressive effect of FK506, suggesting that the mechanism depends on FK506-binding protein (FKBP) 51 expression. Overall, our results add new insights into the role of FK506, not only on T-cell cytokine secretion but also on co-inhibitory molecular regulation and target cell immune privilege.

Diagnosis and treatment of Merkel cell carcinoma: European consensus-based interdisciplinary guideline - Update 2022

Merkel cell carcinoma (MCC) is a rare skin cancer, accounting for less than 1% of all cutaneous malignancies. It is found predominantly in white populations and risk factors include advanced age, ultraviolet exposure, male sex, immunosuppression, such as AIDS/HIV infection, haematological malignancies or solid organ transplantation, and Merkel cell polyomavirus infection. MCC is an aggressive tumour with 26% of cases presenting lymph node involvement at diagnosis and 8% with distant metastases. Five-year overall survival rates range between 48% and 63%. Two subsets of MCC have been characterised with distinct molecular pathogenetic pathways: ultraviolet-induced MCC versus virus-positive MCC, which carries a better prognosis. In both subtypes, there are alterations in the retinoblastoma protein and p53 gene structure and function. MCC typically manifests as a red nodule or plaque with fast growth, most commonly on sun exposed areas. Histopathology (small-cell neuroendocrine appearance) and immunohistochemistry (CK20 positivity and TTF-1 negativity) confirm the diagnosis. The current staging systems are the American Joint Committee on Cancer/Union for international Cancer control 8th edition. Baseline whole body imaging is encouraged to rule out regional and distant metastasis. For localised MCC, first-line treatment is surgical excision with postoperative margin assessment followed by adjuvant radiation therapy (RT). Sentinel lymph node biopsy is recommended in all patients with MCC without clinically detectable lymph nodes or distant metastasis. Adjuvant RT alone, eventually combined with complete lymph nodes dissection is proposed in case of micrometastatic nodal involvement. In case of macroscopic nodal involvement, the standard of care is complete lymph nodes dissection potentially followed by post-operative RT. Immunotherapy with anti-PD-(L)1 antibodies should be offered as first-line systemic treatment in advanced MCC. Chemotherapy can be used when patients fail to respond or are intolerant for anti-PD-(L)1 immunotherapy or clinical trials.

Challenging Dermatologic Considerations Associated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have emerged as a new paradigm in oncologic care for many malignancies. However, nonspecific immune activation has led to "collateral damage" in the form of immune-related adverse events, with skin being a commonly affected organ. Cutaneous immune-related adverse events include a wide spectrum of clinical presentations and challenging considerations, often necessitating dermatology referral to support diagnosis and management, particularly for atypical presentations or more severe, cutaneous immune-related adverse events that may require specialized dermatologic evaluations including biopsy and histopathology. Close collaborations between oncologists and dermatologists may optimize clinical decision making in the following challenging management settings: non-steroidal therapies for corticosteroid-refractory, cutaneous immune-related adverse events, immune checkpoint inhibitor rechallenge, balancing cutaneous immune-related adverse events and treatments, and immune checkpoint inhibitors in patients with pre-existing autoimmune disease, skin conditions, and organ transplants. These complex clinical decisions that often lack rigorous data should be made in close collaboration with dermatologists to minimize unnecessary morbidity and mortality. This article provides a review of approaches to challenging dermatologic considerations associated with immune checkpoint inhibitor therapies.

Immune checkpoint inhibitors for solid organ transplant recipients: clinical updates

Transplant care continues to advance with increasing clinical experience and improvements in immunosuppressive therapy. As the population ages and long-term survival improves, transplant patient care has become more complex due to comorbidities, frailty, and the increased prevalence of cancer posttransplantation. Immune checkpoint inhibitors (ICIs) have become a standard treatment option for many cancers in non-transplant patients, but the use of ICIs in transplant patients is challenging due to the possibility of disrupting immune tolerance. However, over the past few years, ICIs have gradually started to be used in transplant patients as well. In this study, we review the current use of ICIs after all solid organ transplantation procedures (kidney, liver, heart, and lung). Increasing data suggest that the type and number of immunosuppressants may affect the risk of rejection after immunotherapy. Immunotherapy for cancer in transplant patients may be a feasible option for selected patients; however, prospective trials in specific organ transplant recipients are needed.

Utilization of Immunotherapy for the Treatment of Hepatocellular Carcinoma in the Peri-Transplant Setting: Transplant Oncology View

Simple Summary

Hepatocellular carcinoma is the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Regarding the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC, however, the main concerns about organ rejection in liver transplant patients who will be treated with ICPIs are still the same in both pre-and post-transplant setting. To alleviate those concerns, more global collaborations to explore the safety and efficacy of ICPIs in both the pre-and post-organ transplantation settings are required. The decision to administer ICPI treatment in liver transplant patients should be made on a case-by-case basis according to the goal of care and the availability and efficacy of other treatment options.

Abstract

Hepatocellular carcinoma (HCC) represents the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Surgical resection and radiofrequency ablation in small tumors are included in the treatment options for HCC patients with good liver function profiles. According to the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC. Immune checkpoint inhibitors have resulted in good clinical outcomes in pre-and post-transplant HCC patients, although, some reports showed that certain recipients may face rejection and graft loss. In this review, we aim to illustrate and summarize the utilization of immune checkpoint inhibitor therapies in pre-and post-liver transplants for HCC patients and discuss the assessment of immune checkpoint inhibitor regulators that might determine liver transplant outcomes.

T-cell Exhaustion in Organ Transplantation

Exhaustion of T cells occurs in response to long-term exposure to self and foreign antigens. It limits T cell capacity to proliferate and produce cytokines, leading to an impaired ability to clear chronic infections or eradicate tumors. T-cell exhaustion is associated with a specific transcriptional, epigenetic, and metabolic program and characteristic cell surface markers' expression. Recent studies have begun to elucidate the role of T-cell exhaustion in transplant. Higher levels of exhausted T cells have been associated with better graft function in kidney transplant recipients. In contrast, reinvigorating exhausted T cells by immune checkpoint blockade therapies, while promoting tumor clearance, increases the risk of acute rejection. Lymphocyte depletion and high alloantigen load have been identified as major drivers of T-cell exhaustion. This could account, at least in part, for the reduced rates of acute rejection in organ transplant recipients induced with thymoglobulin and for the pro-tolerogenic effects of a large organ such as the liver. Among the drugs that are widely used for maintenance immunosuppression, calcineurin inhibitors have a contrasting inhibitory effect on exhaustion of T cells, while the influence of mTOR inhibitors is still unclear. Harnessing or encouraging the natural processes of exhaustion may provide a novel strategy to promote graft survival and transplantation tolerance.

Donor-Derived Urothelial Carcinoma in Renal Transplant Recipients

Cancer is a significant cause of morbidity and mortality in recipients of renal transplantation. The vast majority develop from recipient origins, whereas donor-derived malignancies are exceedingly rare. We report 2 cases of poorly differentiated donor-derived urothelial carcinoma (UC) in renal transplantation recipients. The first patient underwent a living-related-donor renal transplantation 24 years prior and presented with back pain, hematuria, and rising creatinine and was found to have a 14 cm mass in the renal allograft with regional lymphadenopathy and liver metastases. Pathology showed UC with small-cell differentiation. The second patient presented with hematuria and rising creatinine and was initially found to have muscle invasive bladder cancer seven years after a deceased donor renal transplantation. Nine months after radical cystectomy, a large 9 cm mass was found on his allograft, for which radical nephrectomy and excision of prior ileal conduit was performed. Pathology showed UC with sarcomatoid differentiation. Short tandem repeat (STR) genotyping confirmed donor-derived origins. Both patient tumors expressed PD-L1 suggesting an additional therapeutic avenue for these rare tumors.

Immunotherapy in liver transplantation for hepatocellular carcinoma: Pros and cons

Liver transplantation (LT) has emerged as a curative strategy for hepatocellular carcinoma (HCC), but contributes to a higher predisposition to HCC recurrence in the immunosuppression context, especially for tumors beyond the Milan criteria. Although immunotherapy has dramatically improved survival for immunocompetent patients and has become the standard of care for a variety of tumors, including HCC, it is mainly used outside the scope of organ transplantation owing to potentially fatal allograft rejection. Nevertheless, accumulative evidence has expanded the therapeutic paradigms of immunotherapy for HCC, from downstaging or bridging management in the pretransplant setting to the salvage or adjuvant strategy in the posttransplant setting. Generally, immunotherapy mainly includes immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and vaccine therapy. ICIs, followed by ACT, have been most investigated in LT, with some promising results. Because of the complex tumor microenvironment and immunoreactivity when immunosuppressants are combined with immunotherapy, it is difficult to reach formulations for immunosuppressant adjustment and the optimal selection of immunotherapy as well as patients. In addition, the absence of effective biomarkers for identifying rejection and tumor response is still an unresolved barrier to successful clinical immunotherapy applications for LT. In this review, we comprehensively summarize the available evidence of immunotherapy used in LT that is specific to HCC. Moreover, we discuss clinically concerning issues regarding the concurrent goals of graft protection and antitumor response.

Renal Cell Carcinoma and Kidney Transplantation: A Narrative Review

Kidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). The cancer can be encountered at different steps in the transplant process. RCC found during work-up of a transplant candidate needs treatment and to limit the risk of recurrence usually a mandatory observation period before transplantation is recommended. An observation period may be omitted for candidates with incidentally discovered and excised small RCCs (<3 cm). Likewise, RCC in the donor organ may not always preclude usage if tumor is small (<2 to 4 cm) and removed with clear margins before transplantation. After transplantation, 90% of RCCs are detected in the native kidneys, particularly if acquired cystic kidney disease has developed during prolonged dialysis. Screening for RCC after transplantation has not been found cost-effective. Treatment of RCC in KTRs poses challenges with adjustments of immunosuppression and oncologic treatments. For localized RCC, excision or nephrectomy is often curative. For metastatic RCC, recent landmark trials in the nontransplanted population demonstrate that immunotherapy combinations improve survival. Dedicated trials in KTRs are lacking. Case series on immune checkpoint inhibitors in solid organ recipients with a range of cancer types indicate partial or complete tumor response in approximately one-third of the patients at the cost of rejection developing in ~40%.

Treatment of Cutaneous Squamous Cell Carcinoma with Immune Checkpoint Inhibitors in Special Populations

Cutaneous squamous cell carcinoma (cSCC) may develop in patients with dysregulated immune activation (pre-existing autoimmune diseases or immunosuppression due to hematopoietic/solid organ transplant recipients), patients with a compromised immune function (long-term immunosuppression), and patients carrying chronic viral infections, or those affected by lymphoproliferative diseases. It should be also considered that patients presenting with immunosuppression have a high incidence of cSCC (65-250-times higher than general population), highlighting the central role played by the immune system in the development of cSCC. All these cases must be considered as "special populations" for treatment with immune checkpoint inhibitors (ICIs), as the safety and activity of these drugs have not been studied on these specific cases, since these patients were excluded from clinical trials leading to approval of ICIs. It is therefore important to gain as much information as possible from the analysis of real-life data, to derive an indication to be adopted in everyday clinical setting. Moreover, therapeutic alternatives other than ICIs are scarce, mainly consisting in chemotherapy and anti-EGFR agents, whose activity is lower than immunotherapy and whose toxicity (particularly with chemotherapy) are not sustainable by this frail population. Here, we describe the current evidence of treatment with ICIs in special populations and conclude that it is necessary to find a balance between treatment risks (toxicities) and benefits (efficacy), as well as engaging a multidisciplinary team of experts to thoroughly manage and treat these patients.

Natural killer cells in liver transplantation: Can we harness the power of the immune checkpoint to promote tolerance?

The roles that natural killer (NK) cells play in liver disease and transplantation remain ill‐defined. Reports on the matter are often contradictory, and the mechanisms elucidated are complex and dependent on the context of the model tested. Moreover, NK cell attributes, such as receptor protein expression and function differ among species, make study of primate or rodent transplant models challenging. Recent insights into NK function and NK‐mediated therapy in the context of cancer therapy may prove applicable to transplantation. Of specific interest are immune checkpoint molecules and the mechanisms by which they modulate NK cells in the tumor micro‐environment. In this review, we summarize NK cell populations in the peripheral blood and liver, and we explore the data regarding the expression and function of immune checkpoint molecules on NK cells. We also hypothesize about the roles they could play in liver transplantation and discuss how they might be harnessed therapeutically in transplant sciences.

Advanced cutaneous squamous cell carcinoma of the head in two renal transplanted patients treated with cemiplimab

It is well known that organ transplant recipients are prone to develop non-melanoma skin cancers, particularly cutaneous squamous cell carcinoma (cSCC). This is explained by the long-term use of immunosuppressants and thus the decrease of the immunosurveillance that protects from developing malignant tumours. Solid organ transplant recipients (SOTRs) are 65-250 times more likely to develop cSCC compared to the general population (Am J Transplant 2017; 17: 2509). Moreover, in these patients cSCCs follow a more aggressive course. Close follow-up and regular skin check-ups by a dermatologist are, therefore, crucial in the management of these patients. When detected early, cSCC can be easily and effectively treated by a simple excision. However, when advanced, outcomes are poor. Immune checkpoints inhibitors (ICIs) have been recently added to our arsenal and represent a breakthrough, having proved to be effective in achieving long-term responses. We, hereby, present two cases of difficult-to-treat cSCCs in renal transplanted patients.

Transplant Oncology: An Evolving Field in Cancer Care

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The application of oncology, transplant medicine, and surgery to improve patients' survival and quality of life is the core of transplant oncology. Hepatobiliary malignancies have been treated by liver transplantation (LT) with significant improved outcome. In addition, as the liver is the most common site of metastasis for colorectal cancer (CRC), patients with CRC who have stable unresectable liver metastases are good candidates for LT, and initial studies have shown improved survival compared to palliative systemic therapy. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years in a stepwise manner; however, they have only been shown to improve patient survival in the setting of limited systemic therapy options. This review illustrates the concept and history of transplant oncology as an evolving field for the management of hepatocellular carcinoma, intrahepatic biliary cancer, and liver-only metastasis of non-hepatobiliary carcinoma. The utility of immunotherapy in the transplant setting is discussed as well as the feasibility of using circulating tumor DNA for surveillance post-transplantation.

Immune checkpoint inhibitors and cardiotoxicity: possible mechanisms, manifestations, diagnosis and management

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are a new class of anticancer drugs that enhance the immune system function and activate T cells against cancerous cells. Although cardiac complications are not common, they could be accompanied with high morbidity and mortality.

AREAS COVERED

Regarding the importance of cardiac complications and their subsequent burden on individuals and the healthcare system, this review attempts to discuss the mechanism, diagnosis, and management of myocarditis, besides recapitulating the possible mechanism of other cardiac adverse events. Moreover, we briefly discuss the concurrent administration of other chemotherapeutic agents.

EXPERT OPINION

Due to insufficient knowledge concerning the physiopathology of immune-related adverse events (irAEs) and their potential further complications, cardiovascular complications in particular and in the context of this paper's focus, cooperation of oncologists, immunologists, and cardiologists is necessary for the management of patients. Experimental approaches such as using corticosteroids are becoming a part of guidelines for managing cardiac irAEs. However, a unique algorithm for diagnosis and management is necessary, especially in myocarditis cases. Furthermore, more studies are required to resolve current challenges, including prevention of myocarditis, concurrent administration of other chemotherapeutic agents, and re-introducing patients with ICIs.

Immune Checkpoint Inhibitors in Special Populations

Cancer is the second leading cause of death in the worldwide. With the growing burden of cancer, the studies on early diagnosis, treatment and prevention of cancer are rapidly increasing. Recently, many new therapeutic strategies have been discovered, among which immunotherapy has dramatically changed the outlook for cancer treatment. Several clinical trials are underway around the world to produce potential treatments. However, these trials set certain strict joining conditions, so that the clinical data cannot be fully applied in the real world. To help clinical oncologists with treatment decision-making, this review collected recent studies on special populations receiving immunotherapy, including organ transplant patients, pregnant women, pediatric patients, patients with pulmonary tuberculosis, patients with human immunodeficiency virus, and patients with autoimmune diseases and mental illness.

Malignancies after pediatric solid organ transplantation

As life expectancy among pediatric solid organ transplant recipients (SOTRs) improves, the risk of comorbid conditions such as malignancy post-transplantation has also increased. SOTRs are at elevated risks of post-transplantation lymphoproliferative disorders (PTLDs), and skin and solid cancers. PTLDs typically occur early following transplantation, while skin and solid cancers frequently arise in young adulthood (25-40 years). By 30 years following transplantation, 26-41% of pediatric SOTRs have developed cancer. Different risk factors exist for PTLD, and skin and solid cancers, which are modified by cumulative immunosuppression, infections, transplanted organ, and the underlying disease process associated with initial organ failure (e.g., kidney failure). Optimal cancer treatment strategies depend on the specific cancer type, stage, and patient comorbidities. Immunosuppression reduction may be beneficial for certain cancers but must be considered against the risks of acute and chronic rejection and allograft loss. Lifestyle counseling regarding smoking avoidance and sun protection, as well as human papillomavirus vaccination, is an important aspect of cancer prevention. Currently, no cancer screening guidelines exist specifically for pediatric SOTRs. Adult population screening guidelines have not been validated in transplant populations. Therefore, an individualized approach should be taken to cancer screening for pediatric SOTRs, accounting for other cancer risk factors.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immune checkpoint inhibitor-related adverse events

Immune checkpoint inhibitors (ICIs) are the standard of care for the treatment of several cancers. While these immunotherapies have improved patient outcomes in many clinical settings, they bring accompanying risks of toxicity, specifically immune-related adverse events (irAEs). There is a need for clear, effective guidelines for the management of irAEs during ICI treatment, motivating the Society for Immunotherapy of Cancer (SITC) to convene an expert panel to develop a clinical practice guideline. The panel discussed the recognition and management of single and combination ICI irAEs and ultimately developed evidence- and consensus-based recommendations to assist medical professionals in clinical decision-making and to improve outcomes for patients.

Immune checkpoint inhibitor therapy-associated graft intolerance syndrome in a failed kidney transplant recipient

Immune checkpoint inhibitors (ICPIs) are monoclonal antibodies against inhibitory receptors on T cells resulting in anticancer activity. In kidney transplant (KT) recipients, ICPI use has been associated with acute allograft rejection. In failed allografts, however, the effects of ICPIs are unknown. We present a case of a 66-year-old man with a history of diabetes, renal cell cancer, left native nephrectomy, and end-stage kidney disease. He received a deceased donor KT which failed after 6 years due to biopsy-proven recurrent diabetic nephrosclerosis. He was started on hemodialysis and his immunosuppression was gradually weaned off. A year later, he was diagnosed with renal cell cancer in his right native kidney requiring nephrectomy. He later developed metastasis and was started on combination ICPIs. He developed hematuria, allograft pain, and malaise consistent with graft intolerance syndrome 28 days after starting ICPIs. Urine culture and cystoscopy were normal. A computed tomography scan of his abdomen revealed an enlarged allograft with patchy enhancement. After a multidisciplinary discussion, he underwent transplant nephrectomy. Histopathology showed chronic active T cell-mediated rejection. As ICPI use becomes prevalent, practitioners need to be aware of its potential complications among KT recipients both with functioning and failed allografts.

Managing viral hepatitis in cancer patients under immune checkpoint inhibitors: should we take the risk?

More patients with chronic hepatitis B and C infection are being exposed to immune checkpoint inhibitors (ICIs), but the safety and efficacy of ICIs in patients with chronic viral hepatitis are still poorly described. To explore this interaction, we identified eight studies of cancer patients with viral hepatitis treated with one or more ICIs, formally assessed tumor responses and safety by grading liver dysfunction. ICIs appear to be relatively safe in HBV/HCV-infected patients, and hepatitis related to viral reactivation is rare. In some patients, viral load regressed during ICI treatment, so immune checkpoints may play a role in viral clearance. HBV/HCV do not appear to be a contraindication to ICIs, although careful clinical and biochemical follow-up is recommended and, whenever necessary, antiviral therapy commenced.

Safe Administration of Cemiplimab to a Kidney Transplant Patient with Locally Advanced Squamous Cell Carcinoma of the Scalp

Immunotherapies directed at T-cell activation through antibodies targeting checkpoint proteins, such as programmed cell death 1 (PD1), are rapidly becoming the new standard of care in the treatment of several malignancies. Cemiplimab is a monoclonal antibody targeting PD1 that has recently emerged as a highly active treatment for locally advanced and metastatic cutaneous squamous cell carcinoma (CSCC). Patients who have received an organ transplant (OTRs) have been traditionally excluded from clinical trials with checkpoint inhibitors (CIs), given concerns for organ rejection. Renal transplant recipients (RTRs) are more likely to develop cancers than the general population, and skin cancers are among the most frequent malignancies. We report the case of a 72-year-old man with a history of a kidney transplant who presented with a rapidly growing, locally advanced squamous cell carcinoma (SCC) of the scalp that recurred within four weeks from surgical resection. The patient was able to safely receive ten cycles of cemiplimab so far with significant clinical benefit, and no issues with his kidney function, while continuing immunosuppression with low dose prednisone alone. An ongoing clinical trial (NCT04339062) is further exploring the safety of CIs in patients with metastatic CSCC who have previously received allogeneic hematopoietic stem cell transplant or a kidney transplant.

Lung Cancer Immunotherapy in Transplant Patients and in Patients With Autoimmune Diseases

The use of immune checkpoint inhibitors (ICIs) delivered great and new possibilities in modern treatment of many types of cancers. This therapy based on blockade of such molecules as CTLA-4 (cytotoxic T lymphocyte-associated antigen), PD-1 (programmed cell death receptor type 1), or PD-1 ligand (PD-L1) brings a new hope for patients with non-small cell lung cancer (NSCLC), melanoma, or head and neck squamous carcinoma. Efficacy of immunotherapy was proven in many clinical trials. Unfortunately, ICIs treatment was not addressed to the patients with preexisting allogeneic transplants or autoimmune diseases mainly due to high risk of transplant rejection, exacerbation of autoimmune diseases, and risk of serious toxicity. However, it is possible to receive anti-tumor response to ICIs treatment avoiding graft rejection by adjusting the immunosuppression. Obviously, it depends on the type of transplants: the use of immunotherapy is usually possible in kidney or corneal recipients, but it could be difficult in patients with liver and heart transplant. Therefore, the development of biomarkers for tumor response and transplant rejection in ICIs treated patients is essential. Data coming from published literature support the possibilities of using ICIs in patients with preexisting autoimmune diseases who undergoing proper management of side effects of immunotherapy or when the potential benefits of such treatment outweigh the potential risks. This depends on the type of autoimmune disease and may be difficult or not feasible in patients with systemic lupus erythematosus or systemic sclerosis. Therefore, it may be appropriate to include cancer patients with preexisting autoimmune disease or with allogeneic transplants in clinical trials using immunotherapy when no other effective cancer treatment options exist.

Understanding, predicting and achieving liver transplant tolerance: from bench to bedside

In the past 40 years, liver transplantation has evolved from a high-risk procedure to one that offers high success rates for reversal of liver dysfunction and excellent patient and graft survival. The liver is the most tolerogenic of transplanted organs; indeed, immunosuppressive therapy can be completely withdrawn without rejection of the graft in carefully selected, stable long-term liver recipients. However, in other recipients, chronic allograft injury, late graft failure and the adverse effects of anti-rejection therapy remain important obstacles to improved success. The liver has a unique composition of parenchymal and immune cells that regulate innate and adaptive immunity and that can promote antigen-specific tolerance. Although the mechanisms underlying liver transplant tolerance are not well understood, important insights have been gained into how the local microenvironment, hepatic immune cells and specific molecular pathways can promote donor-specific tolerance. These insights provide a basis for the identification of potential clinical biomarkers that might correlate with tolerance or rejection and for the development of novel therapeutic targets. Innovative approaches aimed at promoting immunosuppressive drug minimization or withdrawal include the adoptive transfer of donor-derived or recipient-derived regulatory immune cells to promote liver transplant tolerance. In this Review, we summarize and discuss these developments and their implications for liver transplantation.

Poor Outcomes With the Use of Checkpoint Inhibitors in Kidney Transplant Recipients

BACKGROUND

Checkpoint inhibitors are now frequently used for oncologic conditions. The impact of these therapies in solid organ transplant recipients was not assessed in clinical trials. Subsequent case reports highlight the major detrimental interactions of checkpoint inhibitors and the high risk of allograft rejection with their use. Patient outcomes have not been assessed in long-term follow-up.

METHODS

We conducted a retrospective review of kidney transplant recipients with metastatic cancer who received checkpoint inhibitors at a single center between April 2015 and May 2018.

RESULTS

Six kidney transplant recipients with metastatic cancers that were not responding to first-line treatments met study criteria. These include 2 with squamous cell cancers, 2 with melanoma, 1 with renal cell cancer, and 1 with adenocarcinoma of the lung. Four patients received anti-programmed cell death protein-1 (PD-1) antibody and 2 received a combination of anticytotoxic T-lymphocyte-associated protein 4 and anti-PD-1 antibodies. Three out of 6 patients developed acute kidney injury. Two were biopsy-proven acute rejections with subsequent graft failures. The third was attributed to rejection, but improved after discontinuing the checkpoint inhibitor. Five out of 6 patients had cancer progression and only 1 patient had remission.

CONCLUSIONS

Providers and patients need to be aware of the high risk of rejection and the poor remission rate with the use of checkpoint inhibitors in kidney transplant patients. More research is warranted to assess the optimal maintenance immunosuppression during the use of checkpoint inhibitor therapy that would not diminish the chances of remission.

Modulating the wayward T cell: New horizons with immune checkpoint inhibitor treatments in autoimmunity, transplant, and cancer

The T-cell response is regulated by the balance between costimulatory and coinhibitory signals. Immune checkpoints are essential for efficient T-cell activation, but also for maintaining self-tolerance and protecting tissues from damage caused by the immune system, and for providing protective immunity. Modulating immune checkpoints can serve diametric goals, such that blocking a coinhibitory molecule can unleash anti-cancer immunity whereas stimulating the same molecule can reduce an over-reaction in autoimmune disease. The purpose of this review is to examine the regulation of T-cell costimulation and coinhibition, which is central to the processes underpinning autoimmunity, transplant rejection and immune evasion in cancer. We will focus on the immunomodulation agents that regulate these unwanted over- and under-reactions. The use of such agents has led to control of symptoms and slowing of progression in patients with rheumatoid arthritis, reduced rejection rates in transplant patients, and prolonged survival in patients with cancer. The management of immune checkpoint inhibitor treatment in certain challenging patient populations, including patients with pre-existing autoimmune conditions or transplant patients who develop cancer, as well as the management of immune-related adverse events in patients receiving antitumor therapy, is examined. Finally, the future of immune checkpoint inhibitors, including examples of emerging targets that are currently in development, as well as recent insights gained using new molecular techniques, is discussed. T-cell costimulation and coinhibition play vital roles in these diverse therapeutic areas. Targeting immune checkpoints continues to be a powerful avenue for the development of agents suitable for treating autoimmune diseases and cancers and for improving transplant outcomes. Enhanced collaboration between therapy area specialists to share learnings across disciplines will improve our understanding of the opposing effects of treatments for autoimmune disease/transplant rejection versus cancer on immune checkpoints, which has the potential to lead to improved patient outcomes.

Clinical outcomes of solid organ transplant recipients with metastatic cancers who are treated with immune checkpoint inhibitors: A single-center analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy, but to the authors' knowledge, limited data exist regarding the safety and efficacy of these agents in transplant recipients. Herein, the authors have reported their experience with 17 patients who were treated with ICIs for metastatic malignancies after undergoing solid organ transplantation.

METHODS

Data were abstracted for solid organ transplant recipients who received ICIs for the treatment of malignancy between January 1, 2016, and September 30, 2019. The authors identified 7 kidney, 8 liver, and 2 heart transplant recipients. Outcomes of interest were adverse drug reactions, cancer progression, and patient survival.

RESULTS

The most common malignancies treated with ICIs were metastatic squamous cell carcinoma (5 patients; 29%) and hepatocellular carcinoma (5 patients; 29%), which were noted exclusively among liver transplant recipients. The median duration on ICIs was 1.7 months (interquartile range, 0.4-7.6 months). Five patients (29%) developed adverse reactions, including 4 patients (24%) with immune-related adverse events(irAEs), 3 patients (18%) with acute allograft rejections, 1 patient (6%) with autoimmune colitis, and 1 patient (6%) with ICI-induced cardiotoxicity (the patient was a heart transplant recipient). The cumulative incidence of cancer progression was 50% and 69%, respectively, at 6 months and 12 months. Eleven patients (65%) died over the median follow-up period of 4.6 months (interquartile range, 1.5-13.2 months) from the time of ICI initiation, with cancer progression being the most common cause of death.

CONCLUSIONS

ICIs can be used as individualized therapy in selected patients who have undergone solid organ transplantation but more studies are needed to determine how best to use these agents to improve outcomes further.

Kidney retransplantation after anti-programmed cell death-1 (PD-1)-related allograft rejection

In this report, we describe the first kidney retransplantation performed after anti-programmed cell death-1 (PD-1)-related allograft rejection. In 2014, we administered pembrolizumab (anti-PD-1) for ~9 months to a 57-year-old kidney transplant recipient with metastatic cutaneous squamous cell carcinoma (CSCC). The patient experienced both a complete antitumor response and T cell-mediated allograft rejection requiring reinitiation of hemodialysis. Four-and-a-half years after initiating pembrolizumab, the patient remained without evidence of CSCC relapse and received a kidney transplant from a living-unrelated donor. Ten-and-a-half months after kidney retransplantation, the allograft is functioning well and the patient's CSCC remains in remission. This case illustrates the potential for PD-1 blockade to bring about durable immune-mediated tumor control in chronically immunosuppressed patients, and begins to address the feasibility of kidney retransplantation in patients who have previously received immune checkpoint inhibitor therapy for cancer. Results from this and future cases may help elucidate mechanisms of antitumor immunity and allograft tolerance, and inform updates to transplant decision models. Our report also underscores the need for clinical trials testing novel immunotherapy combinations in solid organ transplant recipients designed to uncouple antitumor and anti-allograft immunity.

Immune Checkpoint Inhibitors and Immune-Related Adverse Renal Events

Renal toxicities have been increasingly recognized as complications of the immune checkpoint inhibitors (ICIs). Recent studies have outlined the incidence and potential risk factors for nephrotoxicity. For clinicians, the key question is how to manage patients who develop these adverse renal effects. This is of paramount importance to providers as ICI use for cancer therapy becomes more widespread and nephrotoxicity increasingly develops. As clinicians encounter ICI-associated nephrotoxicity, an appropriate approach to management is required to facilitate the best outcomes in patients with cancer. Importantly, ICI rechallenge in patients who developed ICI-related acute kidney injury (AKI) is unclear and represents a conundrum for providers. Clinicians struggle with the "if, when, and how to" questions related to ICI rechallenge in this subset of patients. In addition, ICI use in the transplant population raises concerns for promoting acute rejection when treating cancer in these patients. We herein review current information on these various topics.

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.

Side effect management during immune checkpoint blockade using CTLA-4 and PD-1 antibodies for metastatic melanoma - an update

CTLA-4 and PD-1 play a key role in tumor-induced downregulation of lymphocytic immune responses. Immune checkpoint inhibitors have been shown to alter the immune response to various cancer types. Anti-CTLA-4 and anti-PD-1 antibodies affect the interaction between tumor, antigen-presenting cells and T lymphocytes. Clinical studies of the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab have provided evidence of their positive effects on overall survival in melanoma patients. Combined treatment using ipilimumab and nivolumab has been shown to achieve five-year survival rates of 52 %. Such enhancement of the immune response is inevitably associated with adverse events. Knowledge of the spectrum of side effects is essential, both in terms of prevention and management. Adverse events include colitis, dermatitis, hypophysitis, thyroiditis, hepatitis and other, less common autoimmune phenomena. In recent years, considerable progress has been made in the detection and treatment of the aforementioned immune-related adverse events. However, early diagnosis of rare neurological or cardiac side effects, which may be associated with increased mortality, frequently pose a challenge. The present update highlights our current understanding as well as new insights into the spectrum of side effects associated with checkpoint inhibitors and their management.

Autoimmune diseases and immune-checkpoint inhibitors for cancer therapy: review of the literature and personalized risk-based prevention strategy

Patients with cancer and with preexisting active autoimmune diseases (ADs) have been excluded from immunotherapy clinical trials because of concerns for high susceptibility to the development of severe adverse events resulting from exacerbation of their preexisting ADs. However, a growing body of evidence indicates that immune-checkpoint inhibitors (ICIs) may be safe and effective in this patient population. However, baseline corticosteroids and other nonselective immunosuppressants appear to negatively impact drug efficacy, whereas retrospective and case report data suggest that use of specific immunosuppressants may not have the same consequences. Therefore, we propose here a two-step strategy. First, to lower the risk of compromising ICI efficacy before their initiation, nonselective immunosuppressants could be replaced by specific selective immunosuppressant drugs following a short rotation phase. Subsequently, combining ICI with the selective immunosuppressant could prevent exacerbation of the AD. For the most common active ADs encountered in the context of cancer, we propose specific algorithms to optimize ICI therapy. These preventive strategies go beyond current practices and recommendations, and should be practiced in ICI-specialized clinics, as these require multidisciplinary teams with extensive knowledge in the field of clinical immunology and oncology. In addition, we challenge the exclusion from ICI therapy for patients with cancer and active ADs and propose the implementation of an international registry to study such novel strategies in a prospective fashion.

Treatment selection for first-line metastatic renal cell carcinoma in Australia: Impact of new therapy options

Vascular endothelial growth factor receptor tyrosine kinase inhibitors have provided an effective standard of care for the treatment of metastatic clear cell renal cell carcinoma (mRCC). Survival is prolonged with emergence of modern immuno-oncology combination regimens. Prognostic risk assessment is essential for choosing between these therapies to determine the most appropriate first line treatment option, with selection based on International Metastatic RCC Database Consortium Risk Category. We review the current subsidized first line treatments for mRCC in Australia and consider the evidence for treatment selection and sequencing.

Systematic Review of the Safety of Immune Checkpoint Inhibitors Among Kidney Transplant Patients

INTRODUCTION

Kidney transplant (Ktx) recipients are excluded from clinical trials of immune checkpoint inhibitors. The aim of this systematic review was to assess the safety of immune checkpoint inhibitors among Ktx patients.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and Cochrane Database from inception through April 2019. We included studies that reported outcomes of Ktx recipients who received immune checkpoint inhibitors for cancer treatment. Outcomes of interest were allograft rejection and/or allograft failure.

RESULTS

Twenty-seven articles with a total of 44 Ktx patients treated with immune checkpoint inhibitor were identified. Of 44 Ktx patients, 18 were reported to have acute rejection. Median time from immune checkpoint inhibitors to acute rejection diagnosis was 24 (interquartile range, 10-60) days. Reported types of acute allograft rejection were cellular rejection (33%), mixed cellular and antibody-mediated rejection (17%), and unspecified type (50%). Fifteen (83%) had allograft failure and 8 (44%) died. Three patients had a partial remission (17%), 1 patient achieved cancer response (6%), and 5 patients had stable disease (28%).

CONCLUSION

The findings of our study raise awareness of the increased risk for acute allograft rejection/failure following immune checkpoint inhibitors for cancer treatment among Ktx patients, in particular with programmed cell death 1 (PD-1) inhibitors. Future large-scale clinical studies are required to appraise the pathogenesis and plan optimal balanced therapy that helps sustain graft tolerance.

Successful Treatment of Disseminated Hepatocellular Carcinoma After Liver Transplantation With Nivolumab

The use of immunotherapy in transplant recipients is considered a contraindication because of very high risks for graft loss. The graft loss is to be expected because cytotoxic T-lymphocyte-associated protein-4 and programmed death 1 pathways are implicated in graft tolerance. In this case report, we describe a woman with recurrent, disseminated hepatocellular carcinoma who was successfully treated with nivolumab, an immune checkpoint inhibitor.