Use of Immune Checkpoint Inhibitors in End Stage Kidney Disease Patients, Single Center Experience and Review of the Literature

Diagnosis and management of immune checkpoint inhibitor-associated nephrotoxicity: a position statement from the American Society of Onco-nephrology

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer and are now the backbone of therapy for several malignancies. However, ICIs can cause a spectrum of kidney immune-related adverse events including acute kidney injury (AKI), most commonly manifesting as acute interstitial nephritis (AIN), although glomerular disease and electrolyte disturbances have also been reported. In this position statement by the American Society of Onco-nephrology (ASON), we summarize the incidence and risk factors for ICI-AKI, pathophysiological mechanisms, and clinicopathologic features of ICI-AKI. We also discuss novel diagnostic approaches and promising biomarkers for ICI-AKI. From expert panel consensus, we provide clinical practice points for the initial assessment and diagnosis of ICI-AKI, management and immunosuppressive therapy, and consideration for rechallenge with ICI following AKI episodes. In addition, we explore ICI use in special populations, such as kidney transplant recipients, and propose key areas of focus for future research and clinical investigation.

Sex differences in cancer outcomes across the range of eGFR

BACKGROUND

People with chronic kidney disease (CKD) have increased incidence and mortality of most cancer types. We hypothesized that the odds of presenting with advanced cancer may vary according to differences in estimated glomerular filtration rate (eGFR), that this could contribute to increased all-cause mortality and that sex differences may exist.

METHODS

Data were from Secure Anonymised Information Linkage Databank, including people with de novo cancer diagnosis (2011-17) and two kidney function tests within 2 years prior to diagnosis to determine baseline eGFR (mL/min/1.73 m2). Logistic regression models determined the odds of presenting with advanced cancer by baseline eGFR. Cox proportional hazards models tested associations between baseline eGFRCr and all-cause mortality.

RESULTS

eGFR <30 was associated with higher odds of presenting with advanced cancer of prostate, breast and female genital organs, but not other cancer sites. Compared with eGFR >75-90, eGFR <30 was associated with greater hazards of all-cause mortality in both sexes, but the association was stronger in females [female: hazard ratio (HR) 1.71, 95% confidence interval (CI) 1.56-1.88; male versus female comparison: HR 0.88, 95% CI 0.78-0.99].

CONCLUSIONS

Lower or higher eGFR was not associated with substantially higher odds of presenting with advanced cancer across most cancer sites, but was associated with reduced survival. A stronger association with all-cause mortality in females compared with males with eGFR <30 is concerning and warrants further scrutiny.

Metastatic Melanoma Treatment in Special Populations

ABSTRACT

This review outlines the most up-to-date metastatic melanoma treatment recommendations and relevant risks for patients with solid organ transplants, patients with renal dysfunction, and patients with preexisting autoimmune conditions. These specific treatment populations were excluded from the original clinical trials, which studied immune checkpoint inhibitors and BRAF/MEK inhibitors in the advanced melanoma setting. We have synthesized the current body of literature, mainly case series and retrospective analyses, to reflect the evidence for the treatment of these special patient populations at present.

Case report: Successful treatment of a patient undergoing haemodialysis with multifocal hepatocellular carcinoma using atezolizumab and bevacizumab

In the last five years, the advent of combination immune checkpoint inhibitor atezolizumab and anti-angiogenic agent bevacizumab has transformed treatment of unresectable hepatocellular carcinoma. As patient outcomes improve, healthcare professionals will more frequently encounter patients with concomitant hepatocellular cancer and end stage kidney disease on haemodialysis. We present the first case in the literature of a 58-year-old male with multifocal hepatocellular carcinoma undertaking regular haemodialysis who was successfully treated with atezolizumab and bevacizumab with a partial response and stable disease for two years, who suffered grade 1 fatigue, grade 2 hypertension and eventually grade 3 wound infection leading to cessation of bevacizumab. After disease progression on atezolizumab monotherapy, all chemotherapy was stopped. We embed this case in a review of the current literature of atezolizumab and bevacizumab use in patients undertaking haemodialysis and conclude that both targeted therapies may be safely used in these patients. We recommend joint close management of these patients between oncology and nephrology teams, with initial cardiovascular risk stratification before commencing atezolizumab and bevacizumab therapy. During therapy, there should be regular monitoring of blood pressure, or proteinuria if the patient is oliguric under guidance of the dialysis team if preservation of residual renal function is required.

Maintenance avelumab therapy for urothelial carcinoma in a hemodialysis patient: a case report

In recent years, immune checkpoint inhibitors have attracted attention in treatment for urothelial carcinoma. However, many clinical trials included only patients who had adequate renal function. The efficacy of immune checkpoint inhibitors for hemodialysis patients had not been well-documented. Herein, we report a case of a 73-years-old male with metastatic urothelial carcinoma. He was on maintenance hemodialysis, because he underwent total urinary tract resection for treatment of the urothelial carcinoma in his sixties. He was introduced to our hospital with metastases of lung and pubic bone, and was treated with chemotherapy including gemcitabine and paclitaxel. After two cycles, although his metastases decreased in size, he experienced severe anemia, diarrhea, and duodenitis. Therefore, he transitioned to maintenance therapy with avelumab earlier than initially planned. The treatment achieved 10 months disease control, without significant adverse events. To our best knowledge, this is the first case in which avelumab maintenance therapy achieved disease control of metastatic urothelial carcinoma in a hemodialysis patient.

Onconephrology 2022: An Update

Onconephrology is an upcoming and expanding subspecialty that deals with the intersections between hematology/oncology and nephrology. With the paradigm shift in the understanding of cancer immunobiology and mechanisms of oncotherapeutic drug toxicities, it is important for a nephrologist to have a sound understanding of this field. Over the last 5 years, there have been immense developments in our understanding of kidney-related adverse events from various targeted, immuno- and cellular-based therapies. Pathogenic mechanisms of electrolyte imbalance, hypertension (oncohypertension), and AKI from multiple forms of cancer therapies have been explored. Significant research has also been conducted in the field of transplant onconephrology. In this review, we have tried to assimilate the most recent updates in the last 2 years in this ever-growing and fascinating field.

Two cases of nivolumab plus ipilimumab therapy for dialysis patients with advanced bone metastasis from renal cell carcinoma

Nivolumab and ipilimumab are immune checkpoint inhibitors. Combination therapy with these two drugs has been shown to improve the outcome of advanced renal cell carcinoma. However, data about the safety and the efficacy of combination therapy with these two drugs in hemodialysis patients are small. A 59-year-old male hemodialysis patient presented with bone metastasis from renal cell carcinoma, which was located at the right femur. He received nivolumab plus ipilimumab therapy. At 7 months after treatment, he was diagnosed with diabetes as an immune-related adverse event. He was managed with insulin therapy. At 11 months after treatment, CT revealed cytoreduction of metastasis. A 74-year-old male hemodialysis patient presented with bone metastasis of renal cell carcinoma located at the sacrum and left scapula. He received nivolumab plus ipilimumab therapy. At 6 months after treatment, CT showed no progression of metastasis. Nivolumab and ipilimumab therapy might be a viable treatment for hemodialysis patients with bone metastasis from renal cell carcinoma. However, close attention should be paid immune-related adverse events in such patients.

Hodgkin Lymphoma on Hemodialysis: A Review of Treatment and Recommendations

Chemotherapy for classic Hodgkin lymphoma (cHL) patients on hemodialysis (HD) is an extremely challenging situation because pharmacokinetic and pharmacodynamic studies of most chemotherapeutics are lacking for the HD patient, and the small amount of evidence available comes mostly from case reports and small case series. In this review, we provide recommendations based on treatment experience of cHL patients on HD in the literature. HD patients undergoing chemotherapy are at risk of overdose and toxicities because many drugs are significantly eliminated by the kidneys, and at the same time, are at risk of undertreatment because many drugs are removed by HD. Therefore, dose modifications and timing of drug administration in relation to HD sessions must be carefully planned according to the distinct traits of each chemotherapeutic. We carried out an exhaustive literature review of reports of actual administrations of chemotherapeutics to cHL on HD, and also extrapolated data from reports of the same chemotherapeutics that were administered to HD patients with malignancies other than cHL. We summarized the information found in the literature, and provide practical and balanced recommendations concerning dose modifications and optimal timing of drug administration in relation to HD sessions for each chemotherapeutic. Chemotherapy regimens and individual chemotherapeutics studied in this review include ABVD (doxorubicin + bleomycin + vinblastine + dacarbazine), BEACOPP (bleomycin + etoposide + doxorubicin + cyclophosphamide + vincristine + procarbazine + prednisolone), MOPP (mechlorethamine + vincristine + procarbazine + prednisolone), gemcitabine, vinorelbine, brentuximab vedotin, and PD-1 inhibitors (nivolumab and pembrolizumab).

Use of Immune Checkpoint Inhibitors in Elderly Patients With Chronic Kidney Disease and Renal Cell Carcinoma Metastasis of the Parotid Gland: Case Report and Review of the Literature

Renal cell carcinoma metastasis of the parotid gland is extremely rare, and the present literature review found only 23 cases reported in the last two decades. We present a case of a 75-year-old woman with a colon cancer history who had parotid gland metastasis as the first manifestation of second primary kidney cancer. The presence of multiple comorbidities affected medical decision-making. Therefore the patient was treated primarily with immunotherapy. After four cycles of dual immune checkpoint blockade, this advanced patient still benefited and was changed to nivolumab monotherapy as maintenance therapy.

Case Report: Safety and Efficacy of Enfortumab Vedotin in a Patient With Metastatic Urothelial Carcinoma Undergoing Peritoneal Dialysis

The clinical management of metastatic urothelial carcinoma has significantly evolved with the emergence of monoclonal antibodies and antibody-drug conjugates (ADCs). Enfortumab vedotin (EV) was granted approval by the FDA in 2021 for patients with locally advanced or metastatic urothelial carcinoma who have received prior immunotherapy and platinum-containing chemotherapy. Little to no data exist for the use of EV in patients with concurrent end-stage renal disease (ESRD) using either hemodialysis or peritoneal dialysis (PD). Here, we present the case of a patient with metastatic urothelial carcinoma on PD who failed multiple lines of treatment but demonstrated an impressive response to EV without significant toxicity. We discuss the possible impact of peritoneal dialysis on the pharmacokinetics of ADCs and the potential for safe administration based on known pharmacokinetic data.

Immunotherapy and the Spectrum of Kidney Disease: Should We Individualize the Treatment?

The new targeted cancer therapies including immune checkpoint inhibitors (ICIs) have been demonstrated to improve the survival of oncological patients, even in cases of metastatic cancer. In the past 5 years, several studies have revealed that ICI can produce several immune-mediated toxicities involving different organs, such as the skin, the gastrointestinal tract, the liver, and, of course, the kidney. The most frequent lesion of immunotoxicity in the kidney is acute interstitial nephritis (AIN), although other nephropathies have also been described as a consequence of the use of ICI, such as glomerulonephritis and acute thrombotic microangiopathy, among others. In addition, kidney rejection has also been reported in kidney transplant patients treated with ICI. Normally randomized clinical trials with ICI exclude patients with end-stage kidney disease, namely, patients undergoing dialysis and kidney transplant patients. Several important questions need to be addressed in relation to immunotherapy and patients with kidney disease: (a) when to start corticosteroid therapy in a patient with suspected acute kidney injury (AKI) related to ICI, (b) the moment of nephrologist referral and kidney biopsy indication, (c) management of ICI in patients undergoing dialysis, and (d) the effect of ICI in kidney transplantation, immunosuppressive personalized treatment, and risk of allograft rejection in kidney transplant patients. The objective of this review was to summarize the recently published literature on a wide spectrum of kidney disease patients with cancer and ICI. This review will address three main important groups of individuals with kidney disease and cancer immunotherapy, AKI associated with ICI, patients undergoing dialysis, and kidney transplant recipients. We believe that the information provided in this review will enlighten the personalized ICI treatment in individuals with a broader spectrum of kidney diseases.

Cancer Drug Dosing in Chronic Kidney Disease and Dialysis

Patients with malignancies have a high prevalence of kidney disease and are often treated with antineoplastic agents that undergo kidney metabolism or excretion or clearance via renal replacement therapies. Thus, the dosing of these agents, including classic chemotherapeutic drugs, targeted therapies, and immunotherapy, must take into account patients' kidney function. In this review, we will discuss the pitfalls of accurate measurement of kidney function and how kidney disease affects both pharmacodynamic and pharmacokinetic properties of drugs. Lastly, we will discuss specific agents and summarize current dosing strategies for use in patients with chronic kidney disease and end-stage kidney disease.

Use of Pembrolizumab in End-Stage Renal Disease: A Case Report with Complete Response

Second-line treatment in urothelial carcinoma is not well defined. Immunotherapy has shown good outcomes in this setting, but it has not been tested in patients with end-stage renal disease (ESRD). We present a clinical case describing the use of pembrolizumab in a patient under hemodialysis (HD) that achieved a complete response. A 72-year-old man was diagnosed with urothelial carcinoma in 2001. Following transurethral resection of the bladder tumor, bacillus Calmette-Guérin, and mitomycin treatment, he underwent surgery in 2018. The patient required HD since surgery. A few months after surgery, there was disease progression with lung metastasis. A first-line treatment with carboplatin and gemcitabine was started, but after 5 cycles, disease progression was confirmed. It was decided to initiate second-line treatment with pembrolizumab. After 13 months of immunotherapy, a CT scan showed a complete response with total involution of lung metastasis. Immune checkpoint inhibitors are an option to second-line treatment in urothelial carcinoma. Further studies are needed to clarify the efficacy and tolerance of this therapy in ESRD patients.

Cemiplimab for Locally Advanced Cutaneous Squamous Cell Carcinoma: A Case Series of 3 Unique Scenarios

Cemiplimab, a monoclonal antibody directed against programmed death receptor 1 (PD-1), has shown promising results in cutaneous squamous cell carcinoma (cSCC). In a nonrandomized trial where cemiplimab 3 mg/kg was given every 2 weeks for up to 96 weeks, a 44% response rate was noted. This case series discusses 3 unique scenarios of patients with advanced cSCC treated with cemiplimab. The first case is of an end stage kidney disease (ESKD) patient with failed living donor kidney transplant who had developed recurrent cSCC despite several excisions and topical 5-flurouracil and acitretin therapy. He received 8 cycles of cemiplimab leading to resolution. This case serves as an example of the safety and efficacy of cemiplimab in a complex patient who is a kidney transplant recipient on hemodialysis. The second case describes an elderly gentleman with inoperable cSCC initially treated with radiotherapy who later received 9 cycles of cemiplimab for recurrent metastatic disease with excellent response. This case supports the safe and effective use of cemiplimab in an elderly patient. In the third case, cSCC presented itself as a large fungating mass that would have otherwise necessitated limb amputation and was successfully treated with 18 cycles of cemiplimab. This case highlights the dramatic response to cemiplimab obviating the need for surgical intervention and resulting in limb salvage.

Preoperative renal dysfunction and long-term survival after surgery for non-small cell lung cancer

OBJECTIVE

To investigate the association of preoperative renal dysfunction and long-term outcomes following lung cancer surgery.

METHODS

Using the Japanese Lung Cancer Registry data, we retrospectively examined 16,377 patients who underwent surgery for non-small cell lung cancer during 2010. Patients' renal function status was categorized as follows: serum creatinine <1.5 mg/dL (control, n = 16,169), serum creatinine ≥1.5 mg/dL with no dialysis (nondialysis-dependent chronic kidney disease, n = 113), and dialysis-dependent end-stage renal disease (n = 95). The association of patients' characteristics with overall survival was evaluated using multivariate Cox proportional hazard model.

RESULTS

The 5-year overall survival rates in patients with dialysis-dependent end-stage renal disease and with nondialysis-dependent chronic kidney disease were significantly worse than that in the control group (52.9% and 57.5% vs 78.0%; P < .001 for both comparisons), but were comparable to the reported 5-year overall survival rates in the natural history of end-stage renal disease (∼60%) and moderate to severe chronic kidney disease (∼50%). Cancer causes not related to lung cancer accounted for 62.2% of deaths in dialysis-dependent end-stage renal disease, which was more frequent than that in the control group (P = .002). Dialysis-dependent end-stage renal disease and nondialysis-dependent chronic kidney disease were independent risk factors for overall survival after lung cancer surgery (hazard ratio, 2.05 [P < .001] and hazard ratio, 2.04 [P = .001], respectively).

CONCLUSIONS

Preoperative renal dysfunction may be adversely associated with overall survival after lung cancer surgery. Our findings could aid patients to set proper expectation of the risks and benefits about surgery for lung cancer.

Haemodialysed patient with lung cancer in the COVID-19 era: a clinical challenge

A 66-year-old man was referred to the oncological pneumology consultation due to a mass in the right upper lobe observed in a routine X-ray of the chest. The CT scan confirmed a mass in the same location. The biopsy revealed a lung adenocarcinoma. It was decided to start chemotherapy adapted to kidney function. In April 2020, the patient contracted SARS-CoV-2 infection and developed bilateral pneumonia with partial respiratory failure. He was transferred to the intensive care unit, where he had a positive evolution. In the next 5 months, there was a clinical improvement; however, the CT scan of the chest showed disease progression. After a new multidisciplinary approach, it was decided to start a second line with atezolizumab. After four cycles of atezolizumab, there was a clear clinical improvement, and a reduction by more than 50% in the tumour size, without significant adverse effects.

Kidney injury associated with antitumor therapy: focus on the adverse events of modern immuno-oncological drugs

Immune checkpoint inhibitors (ICIs), including cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and programmed death protein 1 (PD-1) or its ligand (PD-L1), are a new generation of immuno-oncological drugs that to date have demonstrated efficacy in a number of malignancies. The mechanism of ICT inhibitors action consist in the potentiation of the immune response by eliminating the tumor cells inhibitory effect on the T-lymphocytes activation. However, excessive immune system activation can cause the development of a special class of immune-related adverse events (irAEs) involved a wide variety of organs and systems, including the kidneys. Despite the fact that immuno-mediated kidney injury caused by ICI therapy develops quite rarely, it can be serious and determine the patient's prognosis, which necessitates early diagnosis and timely start of treatment. In this regard, awareness of the manifestations of ICI-associated renal irAEs is particularly relevant not only for oncologists and for nephrologists, but for doctors of other specialties. In this review, we elucidated the main variants of immuno-mediated kidney injury caused by ICI therapy, discussed possible predictors and mechanisms of their development, and considers the general principles of diagnosis and management of patients according to the severity of irAEs.

Safety of current immune checkpoint inhibitors in non-small cell lung cancer

Introduction: Immune checkpoint inhibitors (ICIs) achieved response rates around 20% in advanced non-small cell lung cancer (NSCLC) with 8% of patients becoming long-term survivors. Outcomes have improved with the addition of chemotherapy to immunotherapy or the combination of anti-PD(L)1 with anti-CTLA-4 agents.Areas covered: The incidence of immune-related adverse events (irAEs) in patients with NSCLC treated with ICIs varied across clinical trials and real-life studies. The onset of irAEs was 10 weeks. Toxic deaths from irAEs following anti-PD(L)1 administration resulted mainly from pneumonitis. Some irAEs such as rash and thyroiditis were probably associated with better clinical outcomes, though confounding biases exist. Investigations are on-going to determine ideal biomarkers to predict the occurrence, to screen for and to diagnose irAEs.Expert opinion: Prevention, anticipation, detection, treatment and careful monitoring are the five principles that characterize our management of irAEs. Distinguishing immune-induced pneumonitis from progression, pseudo progression, hyper progression, or other etiologies (COVID-19) can be particularly challenging in lung cancer due to the baseline vulnerable pulmonary function and thus requires caution and teamwork. We treat patients according to institutional and international guidelines and we only rechallenge them with ICIs after resolution of the AE and corticosteroid tapering.

[Adverse Drug Effects - how to detect, how to avoid?]

There is no drug therapy without risk for toxicity. The patient must tolerate some toxic or idiosyncratic adverse events (e. g. hand foot syndrome). After life threatening adverse effects, one needs to screen (hyperkalemia). The sick-day-rule should be communicated with the informed patient as for example stopping SGLT2-inhibitors (loss of appetite, hypotension). The list of prescriptions should regularly criticized for dangerous or superfluous medicines (deprescribing).

Nephrotoxicity of Immune Checkpoint Inhibitors: Acute Kidney Injury and Beyond

Immune checkpoint inhibitors (ICIs) are novel humanized monoclonal antibodies that release the brakes on the immune system, resulting in the destruction of tumor cells. ICIs are approved for a variety of hematological and solid organ malignancies, and the list has been growing since the approval of ipilimumab in 2011. ICIs are associated with a variety of immune-related adverse events (irAEs). irAEs commonly affect the skin, the gastrointestinal (GI) tract, and the endocrine system. Acute kidney injury (AKI) due to ICIs (ICI-AKI) occurs in a minority of patients, and it is usually due to acute tubulointerstitial nephritis (ATIN). Treatment with corticosteroids is usually successful. There have been reports of electrolyte disorders due to ICIs, including hyponatremia, hypocalcemia, hypokalemia, and Fanconi syndrome. The diagnosis of electrolyte disorders requires vigilance and routine laboratory monitoring.

Safety and Efficacy of Immune Checkpoint Inhibitors for Patients With Metastatic Urothelial Carcinoma and End-Stage Renal Disease: Experiences From Real-World Practice

BACKGROUND

Immune checkpoint inhibitors (ICIs) are used widely for treating metastatic urothelial carcinoma (mUC). In practical settings, evidence is lacking on the efficacy of ICIs in some difficult-to-treat patients, such as those with end-stage renal disease (ESRD). Herein, we evaluate the safety and efficacy of ICIs for patients with mUC and ESRD.

METHODS

For this retrospective study, patients with mUC who were given ICIs at Kaohsiung Chang Gang Memorial Hospital and Linkou Chang Gung Memorial Hospital between April 2016 and November 2019 were consecutively enrolled. All clinicopathologic data, treatment responses, and adverse events were recorded. The immune-related adverse events (AEs), objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were compared between ESRD and non-ESRD groups.

RESULTS

In total, 129 patients with mUC were enrolled, with 11 patients categorized as the ESRD group. Among these patients with ESRD receiving ICIs, 7 of 11 (63.6%) had high-grade (grade ≥3) AEs, chiefly hematologic toxicity. Some rarely encountered AEs were noted, including toxic epidermal necrolysis, tuberculosis reactivation, ascites, and cytokine release syndrome. Patients in the ESRD group had numerically higher ORR (54.5% vs. 28.8%, p = 0.09), PFS (7.1 vs. 3.5 months, p = 0.42), and OS (not reached vs. 15.4 months) than the non-ESRD group. A multivariate Cox regression model demonstrated that leukocytosis (hazard ratio [HR]: 2.63; 95% confidence interval [CI]: 1.23-5.63; p = 0.01) and neutrophil-to-lymphocyte ratio (HR 2.91; 95% CI: 1.30-6.53; p = 0.01) were independent prognostic factors.

CONCLUSION

Administration of ICIs in patients with mUC and ESRD demonstrated a modest antitumor activity, and should be used with caution for increasing risk of hematologic toxicity.

Evaluation of Checkpoint Inhibitors in Cancer Patients With End-stage Renal Disease on Hemodialysis: Case Series and Review of the Literature

Checkpoint inhibitors (CPIs) have become standard of care for multiple types of malignancies and while end-stage renal disease is not a contraindication, these patients are frequently excluded from clinical trials. As a result, there is limited data regarding the safety and efficacy of CPI use in this patient population. In this case series, we report outcomes and adverse events in 8 patients on hemodialysis treated with CPIs. Treatment was overall well-tolerated with adverse events in 3 of 8 (37.5%) patients, with 1 (12.5%) having a grade 4 adverse event, which is comparable to the rate reported in literature for the overall population receiving CPI. No treatment related deaths were seen. Because of small sample size, efficacy data is limited. Further studies are needed in this patient population to elucidate the true incidence of adverse events and antitumor activity.

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.