Immune-mediated red cell aplasia after anti-CTLA-4 immunotherapy for metastatic melanoma

Rare Immune-Related Adverse Events (irAEs): Approach to Diagnosis and Management

Immune checkpoint inhibitors (ICIs) have revolutionised the treatment landscape across many solid organ malignancies and form part of routine clinical practice in many tumours. As indications for monotherapy, doublet therapy and combination approaches with chemotherapy and targeted agents expand, clinicians must be aware of the wide range of possible immune-related adverse events (irAEs). Common toxicities, including rash, colitis, hepatitis and pneumonitis are well described in the literature, and have established diagnostic and management algorithms. Rarer toxicities, often with an incidence of less than 1%, are less defined. These syndromes can be poorly recognised, may take on a fulminant course and do not have established or evidence-based diagnostic and management strategies. As such, patients may experience increased morbidity, mortality and poorer outcomes, related both to these irAEs as well as how the treatment of these may affect the management of their underlying malignancy. In this review, we aim to explore the incidence, potential biomarkers, pathogenesis, diagnostic work-up and clinical sequelae of a selection of uncommon irAEs, with a focus on myocarditis, neurological and haematologic syndromes. Further prospective research is required to accurately define the incidence and pathogenesis of these conditions, with the aim of increasing clinician awareness of rare irAEs and to assist with a more personalised and mechanism-based approach to these syndromes.

Hematological toxicities of immune checkpoint inhibitors and the impact of blood transfusion and its microbiome on therapeutic efficacy and recipient's safety and survival outcome:A systematic narrative appraisal of where we are now!

Classically, patients with solid and hematologic malignancies have been treated with a combination of chemotherapy with or without a holistic targeted strategy using approved conventional therapy. While the evidence-based use of Immunomodulatory drugs and Immune checkpoint inhibitors (ICIs), including those targeting the PD-1, PD-L1 and CTLA-4, have reshaped the treatment paradigm for many malignant tumors and significantly stretched the life expectancy of patients, as for any interventional therapy, the rise in ICI applications, was associated with the observation of more immune-related hematological adverse events. Many of these patients require transfusion support during their treatment in line with precision transfusion. It has been presumed that transfusion-related immunomodulation (TRIM) and the microbiome can pose immunosuppressive effects on the recipients. Looking to the past and beyond and translating available data into practice in the evolving role of pharmaceutical therapy to ICI-receiving patients, we performed a narrative review of the literature on the immune-related hematological adverse events of ICIs, immunosuppressive mechanisms linked to blood product transfusions, as well as the detrimental impact of transfusions and its related microbiome on the sustained efficacy of ICIs and the patients' survival outcomes. Recent reports are pointing to the negative impact of transfusion on ICI response. Studies have concluded that packed RBC [PRBC] transfusions lead to an inferior progression-free and overall survival in patients with advanced cancer receiving ICIs, even after adjustments for other prognostic variables. The attenuation of the effectiveness of immunotherapy likely results from the immunosuppressive effects of PRBC transfusions. It is, therefore, wise to look retrospectively and prospectively at the impact of transfusion on ICI effects and adopt, in the interim, a restrictive transfusion strategy, if applicable, for those patients.

Immune checkpoint inhibitor-induced pure red cell aplasia: Case series and large-scale pharmacovigilance analysis

INTRODUCTION

Impressive advances in immunotherapy, especially immune checkpoint inhibitors (ICIs), have made great progress in treating multiple cancers. However, ICIs can also cause serious, even incurable, immune-related adverse events (irAEs), most often in patients with colitis, dermatitis, hepatitis, and thyroiditis. Rare autoimmune hematologic toxicities have been reported in the literature but are poorly described. Pure red cell aplasia (PRCA) induced by ICIs is a life-threatening autoimmune disease; however, only a few cases have been reported in the literature.

OBJECTIVE

To characterize and evaluate PRCA associated with different ICI regimens in a public database and to review the relevant literature.

METHODS

We described a case series of patients experiencing PRCA while on ICIs. We also mined the Food and Drug Administration's Adverse Event Reporting System (FAERS) and used reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms to analyze the data of the suspected adverse events of PRCA induced by ICIs between January 2011 and June 2022.

RESULTS

Fifteen patients with PRCA events while on ICIs were included in our case series. In FAERS, a total of 41 individual case safety reports (ICSRs) with different ICI regimens were retrieved, among which 28 (68.3%) were related to monotherapy and three (7.3%) involved a fatal outcome. Signals of PRCA for all four ICI monotherapies (nivolumab, pembrolizumab, durvalumab, and atezolizumab) and ICI combination therapy (ipilimumab/nivolumab) were detected. Ipilimumab/nivolumab presented a higher reporting signal than nivolumab.

CONCLUSIONS

There is a significant reporting signal of PRCA with several ICI agents. Clinicians should be aware of and monitor this potentially fatal adverse event.

Immune-Related Uncommon Adverse Events in Patients with Cancer Treated with Immunotherapy

Immunotherapy has dramatically changed the therapeutic landscape of oncology, and has become standard of care in multiple cancer types in front or late lines of therapy, with some longstanding responses and outstanding results. Notwithstanding, its use has brought a totally unique spectrum of adverse events, characterized by a myriad of diverse manifestations affecting nearly every organ and system of the body, including the endocrine, nervous, cardiac, respiratory and gastrointestinal systems. Uncommon adverse events, defined as those occurring in less than 1% of patients, comprise an even more heterogeneous group of diseases that are being seen more recurrently as the use of immune check-point inhibitors increases and indications spread in different tumor types and stages. Here, we comprehensively review some uncommon, but exceedingly important, immune-related adverse events, with special emphasis in the clinical approach and diagnostic workup, aiming to reunite the evidence published previously, allowing an increase in awareness and knowledge from all specialists implicated in the diagnosis, treatment, and care of cancer patients treated with immunotherapy.

Management and Outcomes of Hematological Immune-related Adverse Events: Systematic Review and Meta-analysis

Data regarding clinical outcomes and management of hematological manifestations of immune checkpoint inhibition (ICI) is limited to case reports, series, and a few retrospective reviews. We aimed to determine the rate of response of hematological immune-related adverse events (irAEs) to immunosuppressive therapy. MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from inception to the present day. Retrospective reports were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. The primary outcome of this study was the rate of response to immunosuppression. Eighty studies (14 case series and 66 individual case reports) were analyzed with a total of 135 patients with ICI-related hematological irAEs. Data analysis showed an average proportional response rate to immunosuppression among hematological irAE entities of 50% (range: 25%-70%). The heterogeneity index (I2) was 0% among reports within each entity. There is a wide spectrum of hematological manifestations to ICI therapy, and to date there is no large randomized-controlled trial data to evaluate the efficacy of treatment strategies for hematological irAEs. We found a variable overall response rate to immunosuppression therapy of around 50%, without statistically significant heterogeneity among different irAE types but significant differences among the different countries of publication. Future studies evaluating the optimal dose and duration of immunosuppressive agents for patients with hematological irAEs should be undertaken.

Current challenges of hematologic complications due to immune checkpoint blockade: a comprehensive review

Immune checkpoint blockade has demonstrated durable clinical benefits in a variety of malignancies. These immune checkpoint inhibitors (ICIs) produce unwanted autoimmune reactions due to an impaired self-tolerance. Hematologic immune-related adverse events (heme-irAEs) have been increasingly reported in the literature with a reported fatality rate of 12%. In this review, we illustrate 3 cases treated at Johns Hopkins Hospital for ICI-induced agranulocytosis, aplastic anemia, and thrombocytopenia. We then summarize the available evidence regarding the incidence and prevalence of heme-irAEs. We identified immune thrombocytopenia and hemolytic anemia as the most commonly reported heme-irAEs which are more commonly observed with nivolumab therapy. Median time to onset of heme-irAEs varies between patients but occurs earlier with CTLA-4 inhibitors than with anti-PD-L1/PD-1 agents. We also describe the current challenges regarding the recurrence of heme-irAEs despite immune checkpoint blockade termination. We provide the available evidence supporting a mixed T-cell and B-cell immune-mediated response. Finally, we review the treatment algorithm of these complications and provide treatment alternatives to steroid-refractory cases.

Management of Hematologic Adverse Events Associated With Immune Checkpoint Inhibitors

Immune checkpoint inhibitors target suppressor receptors, including cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death ligand 1 (PD-L1). The activated T cells are not antigen specific; therefore, the blockade of the immune checkpoint may result in the development of autoimmune adverse events. The most common immune-related adverse events (irAEs) are rash, colitis, and endocrinopathies. However, irAEs that affect the hematologic system are rare and can affect red blood cells (e.g., autoimmune hemolytic anemia), white blood cells, and platelets (e.g., immune thrombocytopenia). Usually one cell line is affected; however, in some cases, multiple cell lines can be affected. Other changes in the hematologic system can also be affected (e.g., cryoglobulinemia, cytokine release syndrome). Due to the rarity and lack of recognition of these AEs, the timing, spectrum of events, and clinical presentation are poorly understood. Management of hematologic irAEs usually involves the use of steroids; however, other agents (e.g., IVIG, cyclosporine, rituximab) or procedures (e.g., plasma exchange, transfusions) can also be used.

Transcriptional Regulation of Cancer Immune Checkpoints: Emerging Strategies for Immunotherapy

The study of immune evasion has gained a well-deserved eminence in cancer research by successfully developing a new class of therapeutics, immune checkpoint inhibitors, such as pembrolizumab and nivolumab, anti-PD-1 antibodies. By aiming at the immune checkpoint blockade (ICB), these new therapeutics have advanced cancer treatment with notable increases in overall survival and tumor remission. However, recent reports reveal that 40-60% of patients fail to benefit from ICB therapy due to acquired resistance or tumor relapse. This resistance may stem from increased expression of co-inhibitory immune checkpoints or alterations in the tumor microenvironment that promotes immune suppression. Because these mechanisms are poorly elucidated, the transcription factors that regulate immune checkpoints, known as "master regulators", have garnered interest. These include AP-1, IRF-1, MYC, and STAT3, which are known to regulate PD/PD-L1 and CTLA-4. Identifying these and other potential master regulators as putative therapeutic targets or biomarkers can be facilitated by mining cancer literature, public datasets, and cancer genomics resources. In this review, we describe recent advances in master regulator identification and characterization of the mechanisms underlying immune checkpoints regulation, and discuss how these master regulators of immune checkpoint molecular expression can be targeted as a form of auxiliary therapeutic strategy to complement traditional immunotherapy.

Refractory thrombotic thrombocytopenic purpura related to checkpoint inhibitor immunotherapy

BACKGROUND

Checkpoint inhibitors enhance T-lymphocyte-mediated antitumor responses, resulting in increased survival for patients with neoplastic disease. However, a subset of patients receiving checkpoint inhibitor therapy may experience adverse complications that include the development of autoimmune conditions, such as thrombotic thrombocytopenic purpura (TTP). Given the potential etiologic differences of checkpoint inhibitor-related autoimmunity, TTP that develops in the presence of checkpoint inhibitors may be refractory to current treatment methods and therefore may require additional treatment and prognostic consideration.

CASE REPORT

Herein, we describe the unique clinical course of a patient who was treated with the combined checkpoint inhibitors nivolumab and ipilimumab for Stage IV malignant melanoma, who subsequently developed TTP. Unlike many patients with TTP, this patient failed to develop a sustained response to therapeutic plasma exchange. Additional use of steroids, anti-CD20, and plasma cell-targeting therapy (bortezomib) also failed to substantially reverse thrombocytopenia in a sustainable fashion. During this time, her melanoma progressed, and she ultimately succumbed.

CONCLUSION

This case illustrates not only that TTP may be a potential complication of checkpoint inhibitor therapy, but also that TTP developing in this setting may result in an unpredictable response to commonly employed TTP treatment modalities. Ultimately, checkpoint inhibitor-related TTP may require distinct management approaches and prognostic considerations.

Nivolumab-Induced Thrombotic Thrombocytopenic Purpura in a Patient with Anal Squamous Cell Carcinoma: A Lesson on Hematologic Toxicity from Immunotherapy

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening microangiopathic hemolytic anemia characterized by thrombocytopenia, hemolytic anemia, and ischemic organ damage. It is mainly caused by an autoreactive antibody directed at ADAMTS13. Immunotherapy is frequently associated with autoimmune complications in patients with cancer, but only three cases of TTP have been reported, none implicating single treatment with the anti-programmed cell death receptor 1 ligand antibody nivolumab. We present the first identified and reported case of nivolumab-associated TTP in a 51-year-old woman with stage IIIc anal carcinoma who achieved complete response following chemoradiation and received adjuvant nivolumab as part of a randomized clinical trial. Twelve weeks into treatment, she presented with dark urine, progressive fatigue, and headache. TTP diagnosis was based on laboratory evidence of hemolytic anemia, thrombocytopenia, and ADAMTS13 activity of 9% associated with an inhibitor. She was treated with daily plasma exchange and oral prednisone and responded well to treatment, with platelet counts over 100 K/cmm within 4 days. We reviewed and summarized data from all reported cases of TTP associated with cancer immunotherapy. We provide guidance on identification and management of this devastating hematologic complication, focusing on the importance of early recognition, as most patients achieve complete recovery with appropriate treatment. KEY POINTS: Thrombotic thrombocytopenic purpura (TTP) was originally excluded from previous reviews of hematologic immune-related adverse events; however, several cases have been reported in the past 2 years in patients treated with either single agent or combination of cytotoxic T-lymphocyte-associated antigen 4 and the programmed cell death receptor 1 (PD-1) or the PD-1 ligand inhibitors. Although rare, TTP is a life-threatening condition that could be challenging to diagnose, and early recognition is key as delayed treatment is associated with significant increase in mortality. The pathophysiology of immunotherapy-induced TTP is likely related to autoimmune inhibition of ADAMTS13; the addition of prednisone and rituximab to urgent plasmapheresis appears to be effective and should be part of the up-front management for these patients.

Diagnosis and Management of Hematological Adverse Events Induced by Immune Checkpoint Inhibitors: A Systematic Review

There has been less volume of literature focusing on the Immune-related Hematological Adverse Drug Events (Hem-irAEs) of Immune Checkpoint Inhibitors (ICPis) in cancer patients. Furthermore, there has been no consensus about the management of hematological toxicity from immunotherapy in the recently published practice guidelines by the European Society for Medical Oncology (ESMO). We conducted a systematic review of case reports/series to describe the diagnosis and management of potentially rare and unrecognized Hem-irAEs. We searched Medline, OVID, Web of Science for eligible articles. Data were extracted on patient characteristics, Hem-irAEs, and management strategies. We performed quality assessment using the Pierson-5 evaluation scheme and causality assessment using the Naranjo scale. Our search retrieved 49 articles that described 118 cases. The majority of patients had melanoma (57.6%) and lung cancer (26.3%). The most common Hem-irAEs reported with ICPis (such as nivolumab, ipilimumab, and pembrolizumab) were thrombocytopenia, hemolytic and aplastic anemias. Less reported adverse events included agranulocytosis and neutropenia. Steroids were commonly used to treat these adverse events with frequent success. Other used strategies included intravenous immunoglobulins (IVIG), rituximab, and transfusion of blood components. The findings of this review provide more insights into the diagnosis and management of the rarely reported Hem-irAEs of ICPis.

Case Report: Successful Treatment of Steroid-Refractory Immune Checkpoint Inhibitor-Related Pure Red Cell Aplasia With Cyclosporin

Anemia associated with Immune checkpoint inhibitor (ICI) is usually hemolytic and regenerative. Cases of non-regenerative pure red cell aplasia are rare, and typically improve upon drug discontinuation and after corticotherapy. We herein report a case of nivolumab-related erythroblastopenia refractory to steroids in a melanoma patient that improved only after treatment with cyclosporin. Nivolumab had been well tolerated for 2 months after being introduced as an adjuvant treatment. Hemoglobin level then progressively decreased from 12.7 g/dl as baseline value to a nadir of 4.3 g/dL despite transfusion with a total of 29 packed red blood cells in 3 months. Extensive workup including repeated bone marrow examinations led to the diagnosis of pure red cell aplasia. Anemia persisted despite nivolumab discontinuation and over a month of corticotherapy, but improved dramatically 3 days after cyclosporin initiation and did not recur upon cyclosporin tapering. The patient remains cancer-free 9 months after nivolumab withdrawal. This case highlights the under-recognized risk of erythroblastopenia in patients treated with ICI and proves cyclosporin is a valid alternative for the treatment of steroid-refractory cases.

Pembrolizumab-induced Pure Red Cell Aplasia Successfully Treated with Intravenous Immunoglobulin

We herein report a 64-year-old man who was treated with pembrolizumab for relapsed Hodgkin lymphoma. After the third administration of pembrolizumab, he showed acute anemia with a positive direct anti-globulin test. Because of the markedly erythroid hypoplasia, he was diagnosed with pure red cell aplasia (PRCA) caused by pembrolizumab. He was initially treated with prednisolone, but the reticulocytes decreased after tapering prednisolone. He then received high-dose intravenous immunoglobulin (IVIG) with prednisolone, and PRCA was successfully treated. Although the pathogenesis of PRCA caused by immune checkpoint inhibitors (CPIs) remains unclear, IVIG treatment may be effective for some steroid-refractory CPI-induced PRCA cases.

Haematological immune-related adverse events with immune checkpoint inhibitors, how to manage?

Immune checkpoint inhibitors (ICIs) are changing the treatments of many patients with cancer. These immunotherapies are generally better tolerated than chemotherapy, and their adverse events are immune-related mimicking autoimmune or inflammatory conditions. Although these immune-related adverse events mainly affect the skin, endocrine glands, digestive tract, joints, liver or lungs, all the organs can be theoretically affected, and the haematopoietic system is not spared. This review of the literature will focus on the haematological immune-related adverse events (Haem-irAEs). By reviewing the largest clinical trials of ICIs, we estimate the frequency of Haem-irAEs at 3.6% for all grades and 0.7% for grades III-IV. Frequency of Haem-irAEs of all grades was found to be higher with anti-programmed cell death 1 (4.1%) or anti-programmed cell death ligand 1 (4.7%) than with anti-cytotoxic T-lymphocyte-associated protein 4 (0.5%) (p < 0.0001). From the 63 cases with Haem-irAEs reported in the literature, the mean time to the onset was found to be 10 weeks after ICI initiation, and the large range for occurrence (1-84 weeks) and the regular incidence suggest that Haem-irAEs could occur at any time after ICI therapy. Among the 63 reported cases with Haem-irAEs, the distribution was immune thrombocytopenia (n = 18, 29%), pancytopenia or immune aplastic anaemia (n = 12, 19%), neutropenia (n = 11, 17%), haemolytic anaemia (n = 10, 16%), cytokine release syndrome with haemophagocytic syndrome (n = 7, 11%) and other Haem-irAEs including bicytopenia or pure red cell aplasia (n = 5, 8%). Haem-irAEs are generally highly severe adverse reactions with a mortality rate of Haem-irAEs reported to be 14% (9 deaths among the 63 cases reported). The more severe and life-threatening Haem-irAEs were both cytokine release syndrome with haemophagocytic syndrome and pancytopenia or aplastic anaemia. Haem-irAEs induced by ICIs are potentially life-threatening. By discussing their pathophysiological aspects and clinical picture, we propose in this review clinical guidelines for management.

Susceptible loci associated with autoimmune disease as potential biomarkers for checkpoint inhibitor-induced immune-related adverse events

Unprecedented successes regarding cancer immunotherapy have been achieved, in which therapeutic agents are used to target immune cells rather than cancer cells. The most effective immunotherapy to date is the group of immune checkpoint inhibitors (CPI), targeting, for example, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) or programmed cell death protein (PD-1). TThe combination of these therapies (anti-PD-1 with anti-CTLA-4) induces high response rates, and seem to be increased further when applied in early-stage disease. However, combined CTLA-4 plus PD-1 blockade causes frequent high-grade immune-related adverse events (irAE). To date, research on biological mechanism of irAEs is scarce and no widely accepted biomarkers predicting onset of severe irAEs have been identified. The similarity of irAEs to autoimmune disorders fuels the hypothesis that irAEs may be linked to susceptible genetic loci related to various autoimmune diseases. In this review, we extensively searched for susceptible loci associated with various autoimmune diseases, and pooled them in groups most likely to be associated with CPI-induced irAEs. These sets could be used in future research on predicting irAEs and guide physicians in a more refined and personal manner.

Bone Marrow Findings of Immune-Mediated Pure Red Cell Aplasia Following Anti-Programmed Cell Death Receptor-1 Therapy: A Report of Two Cases and Review of Literature

Immune checkpoint inhibitors have recently emerged as important and effective advanced cancer treatment options. Programmed cell death receptor-1 (PD-1) antagonists such as pembrolizumab and nivolumab have been approved by the US Food and Drug Administration for treatment of many advanced cancers. As anti-PD-1 checkpoint inhibitor use has been increasing, previously unreported rare side effects emerge. These checkpoint inhibitors upregulate humoral and cellular immune responses to tumor antigens. Consequently, they can be associated with immune-related adverse events including hematological-related reactions such as autoimmune hemolytic anemia, immune thrombocytopenia, neutropenia and pancytopenia. However, pure red cell aplasia (PRCA) induced by anti-PD-1 checkpoint inhibitors is rarely reported in the literature. We herein report cases of two patients who developed PRCA during treatment with anti-PD-1 checkpoint inhibitors. In both cases, a peripheral blood smear examination demonstrated reticulocytopenia. Bone marrow biopsies revealed severe erythroid hypoplasia with maturation arrest at the proerythroblast stage, relative granulocytic hyperplasia and lymphocytosis. Flow cytometry and immunohistochemistry revealed that the lymphocytes were predominantly CD8⁺ T cells. T lymphocytosis, especially in one of the two patients, mimicked a T-cell lymphoproliferative disorder; lack of clonality indicated a reactive process. Our findings, in addition to data presented in the literature, suggest that T cells play a critical role in the pathogenesis of immune-related PRCA. PRCA is an under-recognized immune-mediated adverse event that does not manifest during the clinical trial phase. It is a potentially life-threatening complication, which should be considered in the differential diagnosis of anemia in patients treated with anti-PD-1 checkpoint inhibitors.

Hematological Side Effects of Immune Checkpoint Inhibitors: The Example of Immune-Related Thrombocytopenia

Immune-related hematological adverse events are amongst the rare but potentially life-threatening complications of immune checkpoint inhibitors. The spectrum of these toxicities is broadening as the number of patients exposed to these agents is increasing. Yet, they are still relatively unknown to many clinicians, possibly due to a lack of specific diagnostic criteria, which poses a challenge for their recognition and proper reporting, and partly due to their low incidence, often too low to be noted in most clinical trial publications. Since early detection and prompt intervention are crucial to prevent fatal consequences, it is of outmost importance that medical staff and patients be aware of these potential toxicities and learn to recognize and treat them adequately. This publication outlines strategies and offers guidance on the detection, diagnosis, risk assessment, monitoring and management of immune-related thrombocytopenia, a relatively common example of immune-related hematological toxicity of immune checkpoint inhibitors.

Aplastic anemia secondary to propylthiouracil: A rare and life-threatening adverse effect

Background

Propylthiouracil has been in use for more than half a century for the treatment of hyperthyroidism. While it is largely known to cause agranulocytosis, its association with aplastic anemia is rarely heard of. Our case will be the third in literature to suggest aplastic anemia as a manifestation of propylthiouracil, which unfortunately culminated in the death of the patient.

Case

A 67-year-old female, with recently diagnosed metastatic adenocarcinoma of the lung, developed hyperthyroidism after being started on Nivolumab and Iplimumab. After she developed atrial fibrillation, she was started on propylthiouracil to control the thyroid activity. Soon after that, she was admitted with severe neutropenia, which progressed to pancytopenia confirmed as aplastic anemia on a bone marrow biopsy. Despite discontinuation of propylthiouracil and aggressive treatment, she developed septic shock and multi-organ failure, leading to her death.

Conclusion

Aplastic anemia has been sparingly reported as an extremely rare complication of propylthiouracil. Further adding to the ambiguity is the unknown etiology and lack of specific therapy for the complication when attributed to propylthiouracil. The disease can carry an extremely poor prognosis if untreated, as proven by our case. Due to the same reasons, we recommend that further investigations be done to elucidate the pathogenesis and assist with treatment of the disease when caused by propylthiouracil.

Bicytopenia in Primary Lung Melanoma Treated with Nivolumab

A 73-year-old man who was a current smoker complained of weakness in his limbs and slow movement and was diagnosed with primary lung melanoma with brain metastases. Following stereotactic brain radiotherapy, nivolumab was administrated. After the first cycle of nivolumab, his blood neutrophil count and hemoglobin levels started to decline. Excluding other possible causes, nivolumab was considered the most probable cause of bicytopenia. Nivolumab was not restarted, and the bicytopenia gradually recovered with no corticosteroid administration for this event. While serious hematological adverse events regarding immune checkpoint inhibitors have been assumed to be rare, severe neutropenia and anemia should be considered in patients receiving immune checkpoint therapy.

Recent advances in nanomaterial-based synergistic combination cancer immunotherapy

This review aims to summarize various synergistic combination cancer immunotherapy strategies based on nanomaterials.

Severe hemophagocytic lymphohistiocytosis in a melanoma patient treated with ipilimumab + nivolumab

BACKGROUND

Treatment of metastatic melanoma patients with immune checkpoint inhibitors is an important standard of care. Side effects are due to immune activation, can affect virtually all organ systems, and are occasionally severe. Although hematologic toxicity has been reported, we present a case of hemophagocytic lymphohistiocytosis (HLH) due to immune checkpoint inhibitor therapy.

CASE PRESENTATION

A patient with metastatic melanoma was treated with one course of ipilimumab + nivolumab and presented 3 weeks later with severe anemia and hyperferritinemia. A bone marrow biopsy revealed necrotic tumor cells, infiltrating T cells, and hemophagocytosis. The patient was treated with high-dose steroids; 12 months later, the patient remains off all therapy and in complete remission of both HLH and metastatic melanoma.

CONCLUSIONS

The hemophagocytic syndromes are attributable to dysregulated immune activation and share pathophysiologic mechanisms with immune activation from checkpoint inhibitors. Increasing use of regimens that include immune checkpoint inhibition require vigilant monitoring for immune-activating side effects as they can occasionally be life threatening, as in this case of HLH.

A case of pure red cell aplasia during nivolumab therapy for cardiac metastatic melanoma

Nivolumab is an antibody against programmed cell death 1 and functions as an immune checkpoint inhibitor for various malignancies, including unresectable melanomas. Nivolumab causes several immune-related adverse events, which typically include skin rash, pneumonitis, thyroid dysfunction, hepatitis, and colitis; in rare cases, anemia may be present. There are several reports of autoimmune hemolytic anemia that has developed in response to nivolumab; however, there are few reports of pure red cell aplasia (PRCA). We describe a patient who developed PRCA during nivolumab administration. A 70-year-old Japanese woman received nivolumab for cardiac metastasis from malignant melanoma from an unknown site. Twenty-one months after nivolumab administration (31 courses), treatment was discontinued because she developed severe anemia. Blood test results indicated normocytic, normochromic anemia, and reticulocytopenia, but all other components were normal. Bone marrow aspiration showed increased megakaryocytes and decreased erythroblasts; these findings were consistent with PRCA. Anemia improved without recurrence after treatment with corticosteroids and blood transfusions. The steroid dosage was reduced gradually, and to date, the patient has not experienced recurrence of anemia. The tumor decreased in size and the patient has shown a continued response to treatment with decrease in disease for 3 years. Although it is unclear how nivolumab causes PRCA, hematological toxicities have been reported in patients treated with immunotherapy drugs. PRCA might be an unrecognized immune-mediated adverse event that did not manifest during the clinical trial phase.

Uncoupling therapeutic from immunotherapy-related adverse effects for safer and effective anti-CTLA-4 antibodies in CTLA4 humanized mice

Anti-CTLA-4 monoclonal antibodies (mAbs) confer a cancer immunotherapeutic effect (CITE) but cause severe immunotherapy-related adverse events (irAE). Targeting CTLA-4 has shown remarkable long-term benefit and thus remains a valuable tool for cancer immunotherapy if the irAE can be brought under control. An animal model, which recapitulates clinical irAE and CITE, would be valuable for developing safer CTLA-4-targeting reagents. Here, we report such a model using mice harboring the humanized Ctla4 gene. In this model, the clinically used drug, Ipilimumab, induced severe irAE especially when combined with an anti-PD-1 antibody; whereas another mAb, L3D10, induced comparable CITE with very mild irAE under the same conditions. The irAE corresponded to systemic T cell activation and resulted in reduced ratios of regulatory to effector T cells (Treg/Teff) among autoreactive T cells. Using mice that were either homozygous or heterozygous for the human allele, we found that the irAE required bi-allelic engagement, while CITE only required monoallelic engagement. As with the immunological distinction for monoallelic vs bi-allelic engagement, we found that bi-allelic engagement of the Ctla4 gene was necessary for preventing conversion of autoreactive T cells into Treg cells. Humanization of L3D10, which led to loss of blocking activity, further increased safety without affecting the therapeutic effect. Taken together, our data demonstrate that complete CTLA-4 occupation, systemic T cell activation and preferential expansion of self-reactive T cells are dispensable for tumor rejection but correlate with irAE, while blocking B7-CTLA-4 interaction impacts neither safety nor efficacy of anti-CTLA-4 antibodies. These data provide important insights for the clinical development of safer and potentially more effective CTLA-4-targeting immunotherapy.

Incidence and Management of Immune-Related Adverse Events in Patients Undergoing Treatment with Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

The unleashing of the immune system in an effort to fight cancer has proven to be an incredible advance in the war on cancer. However that breakthrough has come with a price in the form of serious and potentially fatal immune-related adverse events (irAEs).

RECENT FINDINGS

Rapid recognition and early intervention is imperative to avoid significant morbidity and mortality. Additionally, providers need to be aware that there are still new, rare, and long-term emerging irAEs that were not previously reported in clinical trials. Because of the significant difference between irAEs and those caused by chemotherapy and/or targeted therapy, providers must have a thorough understanding of which events would be considered immune related and require treatment. This review will cover descriptions of the most common and uncommon but serious irAEs experienced by patients on immunotherapy, as well as management of these irAEs.

A multidisciplinary approach to toxicity management of modern immune checkpoint inhibitors in cancer therapy

Immune-related Adverse Events (irAEs) are the most significant toxicities associated with the use of checkpoint inhibitors, and result from disinhibition of the host's immune homeostasis. The adverse effects experienced from immunotherapy are significantly different from those of chemotherapy and, to a lesser extent, targeted therapy. Early recognition and diagnosis of these toxicities is often challenging, but is critically important because of the potentially life-threatening nature and associated morbidity. Gastrointestinal, dermatologic, endocrine, and liver toxicities are the most commonly observed. Less commonly, the eyes, pancreas, kidneys, lungs, bone marrow, or nervous system may be affected. Although most irAEs may resolve with supportive care or discontinuation of drug, in severe cases, they may require hospitalization and immune suppressants, such as steroids, and/or may even cause death. The management of immune-related side effects requires a multidisciplinary approach.

Activity of pembrolizumab in relapsed/refractory NK/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTCL) is a rare subtype of non-Hodgkin lymphoma that is associated with a poor outcome. Currently, the treatment needs of NKTCL remain unmet, and efforts to further improve treatment are urgently needed. Herein, seven patients with NKTCL who failed to respond to various types of chemotherapies were treated with the anti-programmed death 1 (anti-PD-1) antibody pembrolizumab at 100 mg every 3 weeks. After a median of four cycles of treatment (range 2-18), four out of seven patients responded (two complete response, two partial response, overall response rate 57%). Expression of PD1-ligand available was 50, 20, 30, 70, and 30% of five patients respectively. It is negative in one patient and not tested in one patient. Adverse events, which mostly ranged from grade I to grade III, were tolerable and could be safely handled, although immune-related pneumonitis was notable. Overall, PD-1 blockade with pembrolizumab represents a favorable strategy for the treatment of refractory/relapsed NKTCL.

Immune-related adverse events during anticancer immunotherapy: Pathogenesis and management

Immunotherapy is one of the most recent systemic treatments to emerge for use in oncology, and is based on the blocking of inhibitory immune checkpoints to potentiate the immune response to cancer. The anti-cytotoxic T lymphocyte-associated antigen-4 antibody ipilimumab and anti-programmed cell death protein 1 antibodies, including nivolumab and pembrolizumab, are currently available and widely used, and other immune-inhibiting antibodies are now under intensive investigation. These antibodies have shown efficacy in a growing number of tumor types, following initial observations of their notable effects in melanoma treatment. Despite the efficacy of these antibodies, their novel mechanisms of action are also associated with a new class of side effects called immune-related adverse events (IRAEs). These side effects do not share a common pathophysiology with other anticancer treatments and, therefore, they often require specific therapies. When detected early and correctly treated, IRAEs are reversible; however, they can become severe and life-threatening if underestimated or inappropriately treated. This review aims to revisit the pathogenesis of IRAEs, with attention to gastrointestinal manifestations, since these are common and potentially dangerous complications of immunotherapy and represent a major cause of treatment discontinuation. Recommendations and guidelines for the management of IRAEs are also presented, in order to provide a clear and applicable algorithm for use by clinicians.

Rare side-effects of checkpoint inhibitors

PURPOSE OF REVIEW

The aim of this review is to draw the attention of the physicians and oncologists on the rare side-effects of checkpoint inhibitors not usually reported in clinical trials to treat them quickly and render their prognosis better.

RECENT FINDINGS

Rare side-effects of checkpoint inhibitors are mainly neurologic, haematologic, rheumatologic, renal, and cardiac. The majority of reported side-effects are consequent of the treatment by ipilimumab in patients diagnosed with melanomas. Neurologic side-effects have poorer prognosis compared with other rare side-effects. There is no relationship between developing rare side-effects and the outcome of the disease.

SUMMARY

It is important to be aware, when treating patients with checkpoint inhibitors, to detect as early as possible the unpredictable and uncontrollable rare side-effects of these agents. The large spectrum of these rare side-effects should be well documented and reported to assure to the physicians a road map for the diagnosis and the management of these toxicities.

Regression of multifocoal in transit melanoma metastases after palliative resection of dominant masses and 2 years after treatment with ipilimumab

BACKGROUND

Spontaneous regression of metastatic melanoma and delayed responses more than one year after treatment with ipilimumab are rarely seen.

CASE PRESENTATION

Here, we present the case of a patient with in transit metastases from cutaneous melanoma on his right lower extremity who achieved complete regression of all metastatic lesions 13 months after the first of two consecutive palliative resections of dominant masses and more than two years after treatment with ipilimumab.

CONCLUSION

The exact cause of our patient's sudden onset of tumor regression remains speculative. We hypothesize that the operative trauma followed by the postoperative infections augmented an innate immune response.

Toxicity profiles of immunotherapy

Immunotherapies are changing the landscape of advanced solid tumor treatment. These therapies have different mechanisms of action and include oncolytic viruses, checkpoint inhibitors, such as CTLA-4 or PD1/PD-L1 monoclonal antibodies, and CSF-1R antibodies. Given the growing therapeutic impact of these agents in oncology, it is important to better understand their properties. Immunotherapies generate new toxicity profiles that are called immune-related adverse events and require specific management. This review focuses on the mechanisms of action of such side effects, as well as their description and their general management.

Pathogenesis, clinical manifestations and management of immune checkpoint inhibitors toxicity

Immune checkpoint inhibitors have emerged as an effective treatment for several tumor types and their use in clinical practice is expected to further increase in the immediate future. Although these agents are well tolerated, they are associated with a peculiar spectrum of toxicity, which is immune mediated and may potentially affect every organ. However, immune-related adverse events are mostly reversible if promptly diagnosed and adequately treated. Therefore, it is crucial that medical oncologists know how to diagnose and treat immune-related adverse events. This review focuses on the pathogenesis, clinical manifestations and management of immune-related toxicity of anti-CTLA-4 and anti-PD-1 antibodies.

Autoimmune hemolytic anemia induced by anti-PD-1 therapy in metastatic melanoma

We report the occurrence of autoimmune hemolytic anemia in a patient receiving the anti-PD-1 monoclonal antibody, nivolumab, for metastatic melanoma in the presence of known red cell alloantibodies, despite having received prior ipilimumab without evidence of hemolysis. The patient had a history of multiple red cell alloantibodies and a positive direct antiglobulin test, identified at the time of a prior transfusion, which occurred before treatment with ipilimumab. The patient developed symptomatic warm autoimmune hemolytic anemia after four cycles of treatment with nivolumab. Clinical improvement was noted following cessation of the drug and treatment with corticosteroids. Given that there was no prior history of hemolysis, even during treatment with ipilimumab, we hypothesize that anti-PD-1 therapy disrupted peripheral tolerance, unmasking an underlying autoimmune predisposition.

Challenges in the use of immunotherapy in metastatic melanoma

A 65-year-old man with metastatic melanoma was started on immunotherapy, switched to alternative targeted therapy and developed disseminated intravascular coagulation. This case underscores the complexity of interpreting and managing side effects of novel therapies in cancer care, identification of progression versus pseudoprogression and challenges in sequencing treatments in metastatic melanoma.

Overview and management of toxicities of immune checkpoint-blocking drugs

Immunotherapy is considered to be the most important breakthrough in cancer management in the past few years. This success was based on the scientific understanding of immune mechanisms due to improvement in preclinical science and the introduction of new methods of investigation. Immune checkpoint inhibitors (ICIs) are among the most promising drugs in the field of immune-oncology; they represent monoclonal antibodies that modulate the effects of immune checkpoints, such as cytotoxic T lymphocyte Antigen 4 (CTLA-4) and Programmed Cell Death protein 1 (PD-1), which are co-inhibitory signals responsible for immune suppression. Despite clinical benefits, ICIs are immune activating agents that are associated with a number of important side effects (immune-related adverse events-irAEs), attributed to organ-specific inflammation. Herein, we review the toxicities of ICIs, highlighting the importance of early identification and management.

The European Organization for Research and Treatment of Cancer perspective on designing clinical trials with immune therapeutics

Cancer immunotherapy has had a major impact on the established paradigms of drug development and clinical trial research. The innovative mechanism of action of these compounds has resulted in new patterns of response and safety profiles, which pose challenges for the classical trial methodology. In this review we report on the search for the maximum tolerated dose, the recommended phase II dose and the appropriate target population in phase I trials. We provide some statistical considerations on the choice of endpoints for phase II and III trials and the limitations of frequently used trial designs in the presence of a delayed treatment effect, which may be induced by the immune modulating effect of the checkpoint inhibitors. We summarize the currently available data on the safety profile of these new compounds, which can guide protocol safety recommendations. Finally, we report on the current evidence of biomarker development.

Ipilimumab in melanoma

INTRODUCTION

The treatment of melanoma is evolving rapidly over the past few years. Patients with BRAFv600 mutations can be treated with a combination of a BRAF-inhibitor and an MEK-inhibitor. Patients with BRAF wild-type tumors and BRAFv600 mutated tumors can be treated with immunotherapy i.e. check point inhibitors.

AREAS COVERED

We conducted a comprehensive review of the literature on the efficacy and predictive markers, safety, and pharmacoeconomics of ipilimumab in melanoma Expert commentary: Ipilimumab was the first check point inhibitor reaching the clinic, gaining FDA and EMA approval for metastatic melanoma in 2011. Ipilimumab was also approved by FDA in the adjuvant setting for patients with high risk, stage III melanoma. The anti-PD1 directed antibodies pembrolizumab and nivolumab are superior to single agent ipilimumab, which is no longer considered the standard first line treatment in metastatic melanoma. The addition ipilimumab to nivolumab is associated with a higher response rate and a better PFS, particularly in patients with PD-L1 negative tumors, albeit at the cost of a steep increase in grade 3-4 adverse event rate. Definitive survival data on this combination are pending and the selection of patients potentially requiring the combination and its pharmacoeconomic implications are to be elucidated.

Bi-cytopenia possibly induced by anti-PD-1 antibody for primary malignant melanoma of the esophagus: A case report

BACKGROUND

Anti-programmed cell death 1 antibody nivolumab is a promising agent for various cancers. Immune-related adverse events are recognized; however, bi-cytopenia with nivolumab has not been reported.

CASE PRESENTATION

A 73-year-old man was diagnosed with advanced primary malignant melanoma of the esophagus with liver, lung, and lymph node metastases. Previous therapies including dacarbazine and radiation of 39 Gy to the esophageal region were performed, but the liver metastases deteriorated. The patient was then administered nivolumab (2 mg/kg, every 3 weeks). After 3 cycles, the esophageal tumor and lymph nodes showed marked reductions in size, the lung metastases disappeared, and the liver metastases shrank partially. The treatment continued with 7 cycles for 4 months. However, severe anemia and thrombocytopenia appeared in the 6th cycle, and intermittent blood transfusions were required. The patient received high-dose intravenous methylprednisolone therapy for bi-cytopenia, but it was ineffective. Seven months after the initiation of nivolumab, the patient died of tumor. Although the mechanisms of bi-cytopenia were unclear, it could have been induced by nivolumab.

CONCLUSION

The present case shows a rare but serious life-threatening bi-cytopenia possibly associated with nivolumab and suggests the importance of awareness of hematological adverse events during nivolumab therapy.

Pure Red Cell Aplasia Following Interleukin-2 Therapy

A 61-year-old woman with metastatic renal cell carcinoma underwent systemic treatment with high-dose interleukin-2 (IL-2). Anemia requiring transfusion of 1 unit of packed red blood cells (PRBCs) was required during the second week of IL-2 therapy. One month following completion of high-dose IL-2 treatment, she was hospitalized for severe, symptomatic anemia and received 5 units of PRBCs. She was referred back for evaluation. A complete hematologic evaluation was performed including antiviral serology, evaluation for hemolysis, complete iron studies, and finally bone marrow aspiration and biopsy. The diagnosis was pure red cell aplasia, and no inciting viral cause could be ascertained. She required PRBCs for 5 months following IL-2 therapy. It was concluded that IL-2 was the cause of her red cell aplasia. This subsequently resolved spontaneously, and she had normal hemoglobin and hematocrit, respectively, 1 and 2 years after treatment.

Managing immune checkpoint-blocking antibody side effects

Immune checkpoint-blocking antibodies that enhance the immune system's ability to fight cancer are becoming important components of treatment for patients with a variety of malignancies. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) was the first immune checkpoint to be clinically targeted, and ipilimumab, an inhibitor of CTLA-4, was approved by the U.S. Food and Drug Administration (FDA) for patients with advanced melanoma. The programmed cell death-1 (PD-1) receptor and one of its ligands, PD-L1, more recently have shown great promise as therapeutic targets in a variety of malignancies. Nivolumab and pembrolizumab recently have been FDA- approved for patients with melanoma and additional approvals within this therapeutic class are expected. The use of anti-CTLA-4 and anti-PD-1/PD-L1 antibodies is associated with side effects known as immune-related adverse events (irAEs). Immune-related adverse events affect the dermatologic, gastrointestinal, hepatic, endocrine, and other organ systems. Temporary immunosuppression with corticosteroids, tumor necrosis factor-alpha antagonists, mycophenolate mofetil, or other agents can be effective treatment. This article describes the side-effect profile of the checkpoint-blocking antibodies that target CTLA-4 and PD-1/PD-L1 and provides suggestions on how to manage specific irAEs.

Immune-related adverse events with immune checkpoint blockade: a comprehensive review

Cancer immunotherapy is coming of age; it has prompted a paradigm shift in oncology, in which therapeutic agents are used to target immune cells rather than cancer cells. The first generation of new immunotherapies corresponds to antagonistic antibodies that block specific immune checkpoint molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1) and its ligand PD-L1. Targeting these checkpoints in patients living with cancer had led to long-lasting tumour responses. By unbalancing the immune system, these new immunotherapies also generate dysimmune toxicities, called immune-related adverse events (IRAEs) that mainly involve the gut, skin, endocrine glands, liver, and lung but can potentially affect any tissue. In view of their undisputed clinical efficacy, anti-CTLA-4 and anti-PD-1 antibodies are entering in the routine oncological practice, and the number of patients exposed to these drugs will increase dramatically in the near future. Although steroids can be used to treat these IRAEs, the associated immunosuppression may compromise the antitumour response. Oncologists must be ready to detect and manage these new types of adverse events. This review focuses on the mechanisms of IRAE generation, putative relationship between dysimmune toxicity and antitumour efficacy, as a basis for management guidelines.

Management of immune checkpoint blockade dysimmune toxicities: a collaborative position paper

Monoclonal antibodies targeted against the immune checkpoint molecules CTLA-4 and PD-1 have recently obtained approval for the treatment of metastatic melanoma and advanced/refractory non small-cell lung cancers. Therefore, their use will not be limited anymore to selected hospitals involved in clinical trials. Indeed, they will be routinely prescribed in many cancer centers across the world. Besides their efficacy profile, these immune targeted agents also generate immune-related adverse events (irAEs). This new family of dysimmune toxicities remains largely unknown to the broad oncology community. Although severe irAEs remain rare (∼10% of cases under monotherapy), they can become life-threatening if not anticipated and managed appropriately. Over the last 5 years, Gustave Roussy has accumulated a significant experience in the prescription of immune checkpoint blockade (ICB) antibodies and the management of their toxicities. Together with the collaboration of Gustave Roussy's network of organ specialists with expertise in irAEs, we propose here some practical guidelines for the oncologist to help in the clinical care of patients under ICB immunotherapy.

Immune-mediated adverse events of anticytotoxic T lymphocyte-associated antigen 4 antibody therapy in metastatic melanoma

Ipilimumab, an antibody that blocks cytotoxic T lymphocyte-associated antigen 4 (CTLA-4; CD152), was approved by the Food and Drug Administration in 2011 for the treatment of unresectable stage III or IV malignant melanoma. Although the addition of this particular immunotherapy has broadened treatment options, immune-related adverse events (irAEs) are associated with ipilimumab therapy, including dermatologic effects, colitis and diarrhea, endocrine effects, hepatotoxicity, ocular effects, renal effects, neurologic effects, and others. In this article, a critical evaluation of the underlying mechanisms of irAEs associated with anti-CTLA-4 therapy is presented. Additionally, potentially beneficial effects of combinational therapies to alleviate ipilimumab-induced irAEs in malignant melanoma are discussed. Future research is warranted to elucidate the efficacy of such combination therapies and specific biomarkers that would help to predict a clinical response to ipilimumab in patients with malignant melanoma.