A Real-World Disproportionality Analysis of Drug-Induced Immune Hemolytic Anemia in the FDA Adverse Event Reporting System

BACKGROUND

Drug-induced immune hemolytic anemia (DIIHA) is a rare but potentially life-threatening pharmacogenic hematological adverse effect. Updating the risk of DIIHA among the currently available drugs based on spontaneously reported adverse event data is of great significance.

OBJECTIVE

This study aimed to identify the top 50 drugs associated with immune hemolytic anemia in adults as well as common drugs that could cause immune hemolytic anemia in children based on the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database.

METHODS

We extracted adverse events (AE) in the FAERS database from Q1 2004 to Q3 2022 using Open vigil2.1. We use the high-level term "anaemias haemolytic immune" according to the Medical Dictionary for Regulatory Activities (MedDRA) Dictionary (version 24.0). The reported correlation between drugs and DIIHA risk was identified by reported odds ratio (ROR) and proportional reporting ratio (PRR).

RESULTS

There were 10500309 AEs in FAERS from 2004Q1 to 2022Q3, of which 2326 (0.02%) were DIIHA cases. The incidence of DIIHA is comparable between males and females. The most common drugs associated with DIIHA in adults and children are summarized according to the number of AE reports. The top 3 categories in terms of quantity of drugs are antineoplastic agents, immunosuppressants, and antibiotics for systemic use. The top 5 drugs in terms of ROR and PRR are alemtuzumab, daclizumab, fludarabine, busulfan, and bendamustine in adults, with entecavir, treosulfan, vinorelbine, pegademase, and alemtuzumab for children.

CONCLUSIONS

Our study identified the most common drugs that could induce DIIHA in adults and children, as well as the respective ROR and PRR value to discover new drug signals. This study provides references to clinicians for the management of rare DIIHA.

Severe autoimmune hemolytic anemia following immunotherapy with checkpoint inhibitors in two patients with metastatic melanoma: a case report

Introduction

Over the past decade, immune checkpoint inhibitors such as antibodies against cytotoxicity T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have become an important armamentarium against a broad spectrum of malignancies. However, these specific inhibitors can cause adverse autoimmune reactions by impairing self-tolerance. Hematologic side effects of immune checkpoint inhibitors, including autoimmune hemolytic anemia (AIHA), are rare but can be life-threatening.

Case report

Herein, we report two patients on immune checkpoint inhibitors for metastatic melanoma who developed AIHA with symptoms of dyspnea and fatigue. In the first patient, symptoms alleviated after discontinuation of combined anti CTLA-4 and anti-PD-1 therapy, initiation of corticosteroids and application of a single red blood cell transfusion. Due to subsequent progress of melanoma, combinational anti-PD-1 and tyrosine kinase inhibitor therapy was initiated based on multidisciplinary tumor board decision. After two months, she again developed the described hematological and clinical signs of AIHA leading to cessation of anti-PD-1 therapy and initiation of corticosteroids, which again resulted in an alleviation of her symptoms. Due to further progression, the patient received dacarbazine for several months before she decided to stop any therapy other than palliative supportive care. In the second patient, discontinuation of anti-PD-1 therapy and initiation of corticosteroids entailed a complete alleviation of his symptoms. After refusing chemotherapy due to subsequent melanoma progression, he received radiotherapy of bone metastases and is currently enrolled in a clinical trial. The patient did not develop AIHA ever since.

Conclusion

Hematologic immune-related adverse events due to treatment with immune checkpoint inhibitors are rare but can have life-threatening consequences. If dyspnea and other clinical symptoms are present, AIHA should be considered as a potential cause and treated promptly in a multidisciplinary setting. An expanded comprehension of risk factors and pathogenesis of AIHA is needed to identify high-risk patients beforehand, leading to more effective predictive and reactive treatment approaches.

Drug-induced immune hemolytic anemia: detection of new signals and risk assessment in a nationwide cohort study

ABSTRACT

More than 130 drugs have been suspected to induce immune hemolytic anemia. Comparative studies measuring the risk of drug-induced immune hemolytic anemia (DIIHA) are lacking. We aimed (1) to detect new signals of DIIHA, excluding vaccines, and (2) to assess the association between all suspected drugs and the occurrence of immune hemolytic anemia in a nationwide comparative study. The new signals were identified using a disproportionality study (case/noncase design) in the World Pharmacovigilance Database, Vigibase, among the cases of adverse drug reactions reported up to February 2020 (>20 million). We then conducted a comparative study in the French National health database that links sociodemographic, out-of-hospital, and hospital data for the entire population (67 million individuals). Associations between exposure to drugs (those already reported as DIIHA, plus new signals identified in Vigibase) and incident cases of immune hemolytic anemia (D59.0 and D59.1 diagnosis codes of the International Classification of Diseases, version 10) from 2012 to 2018 were assessed with case-control and case-crossover designs. In Vigibase, 3371 cases of DIIHA were recorded. Fifty-nine new signals were identified resulting in a final list of 112 drugs marketed in France and measurable in the nationwide cohort (n = 4746 patients with incident immune hemolytic anemia included in the case-control analysis matched with 22 447 controls from the general population). We identified an association between immune hemolytic anemia occurrence and some antibiotics, antifungal drugs, ibuprofen, acetaminophen, furosemide, azathioprine, and iomeprol.

Tyrosine kinase inhibitor-induced immune hemolytic anemia; three different drugs in three separate cases

INTRODUCTION

Molecular multitargeted small tyrosine kinase inhibitory (TKI) agents such as axitinib, sunitinib and pazopanib are commonly used in several types of solid tumors. Anemia is not a rare effect of these drugs which may occur at all grades. However, drug-induced immune hemolytic anemia (IHA), a very rare condition is distinctive from other types of anemia with its specific mechanism and management strategy.

CASE REPORTS

We reported three different TKI-induced IHA cases that occurred due to axitinib, sunitinib, and pazopanib, respectively. The first two cases were diagnosed with renal cell carcinoma and the last one was diagnosed with soft tissue sarcoma. They all presented with the characteristic symptoms of anemia and hemolysis. All the cases were detected positive for the complement C3d direct antiglobulin (direct coombs) test.

MANAGEMENT AND OUTCOMES

Discontinuation of the causative drug and 1 mg/kg/day dose of corticosteroid treatment were able to control IHA in all three cases. Excluding the other factors of IHA and an evident laboratory and clinical benefit after withholding the TKI led to the diagnosis of TKI-related IHA in each case.

DISCUSSION

TKIs are relatively new in clinical practice and are being used for more indications and in more patients. To our knowledge#these three cases are unique in terms of axitinib#sunitinib#and pazopanib-related IHA.

Checkpoint inhibitors

Immune checkpoint inhibitors are a class of antineoplastic therapies that unleash immune cells to kill malignant cells. These medications commonly cause immune-related adverse effects due to activated adaptive and innate immune cells, autoantibody production, and/or cytokine dysregulation. Hematologic toxicities are rare and of uncertain mechanism, and therefore management is often based on experiences with familiar conditions involving these perturbed immune responses. Management is challenging because one must attend to the hematologic toxicity while simultaneously attending to the malignancy, with the imperative that therapeutic effects be maintained or minimally interrupted when possible.

[In macrohematuria, medication history also needs to be considered : Penicillin-induced immune hemolysis: a case report and review of literature]

BACKGROUND

Drug-mediated immune hemolysis is a rare but potentially life-threatening condition. Based on a case of penicillin-induced immune hemolysis, a structured literature review of case reports and studies on penicillin-mediated Drug-Induced Immune Hemolytic Anemia (DIIHA) was carried out.

CASE REPORT

A 28-year-old male patient presented to the emergency department with gross hematuria and non-specific abdominal complaints. The patient had a 10-day history of respiratory infection with bacterial tonsillitis, treated orally with penicillin V on an outpatient basis. Laboratory diagnostics detected pathologically altered direct and indirect hemolysis parameters. After stopping the medication, the patient's condition could be stabilized.

CONCLUSION

Diagnosis of penicillin-mediated immune hemolysis requires structured cooperation between clinic and laboratory, as clinical and serological findings may be highly variable with the risk of misdiagnosis. Due to the rarity of the disease, this case report is intended to raise awareness with respect to the triad of abrupt drop in hemoglobin levels in connection with drug therapy and in combination with a strongly positive direct Coombs test.

Abatacept as salvage therapy for life-threatening refractory autoimmune hemolytic anemia: a case report

Autoimmune hemolytic anemia (AIHA) can be life-threatening, if hemoglobin (Hb) levels continue to decline after established treatments with glucocorticoids, rituximab, intravenous immunoglobulins, and plasmapheresis. Impaired regulatory T cells (Treg) are proposed to alleviate AIHA development through decreased binding of CTLA-4 to antigen-presenting cells. Abatacept is a fusion protein with a CTLA-4 domain and is approved for use in rheumatoid arthritis. It mimics the immunosuppressive CTLA-4 effect of Treg. Thus, application of abatacept in refractory AIHA might be reasonable. A 54-year-old woman with known AIHA was admitted to our clinic due to therapy-refractory hemoglobin decrease to 4.0 g/dl. Previously, multiple courses of glucocorticoids, rituximab, azathioprine, mycophenolate mofetil, cyclophosphamide, bortezomib, and a splenectomy failed to stop or stabilize hemoglobin levels and hemolysis. A new immunosuppressive therapy with cyclosporine was initiated and erythropoiesis was stimulated with darbepoetin alfa. Again, therapy failed even though we tried to support immunosuppressive therapy by reducing the amount of pathogenic antibody through plasmapheresis. We stopped the treatment with cyclosporine and applied abatacept instead. After seven days hemoglobin stabilized at 4.3 g/dl and no further red blood cells transfusions were necessary. About one month later hemolysis aggravated again and azathioprine was added to the ongoing abatacept treatment. Finally, the combination of abatacept and azathioprine led to a long-lasting increase of the Hb level above 11 g/dl six months later. Abatacept can be applied to overcome therapy refractory autoimmune hemolytic anemia but should be combined with an additional immunosuppressive medication such as azathioprine.

Warm autoimmune hemolytic anemia: new insights and hypotheses

PURPOSE OF REVIEW

Warm autoimmune hemolytic anemia (wAIHA) is the most common of the immune hemolytic anemias. Although there are numerous case reports and reviews regarding this condition, some of the unusual and more recent findings have not been fully defined and may be contentious. This review will provide insight into the common specificity of the warm autoantibodies and hypothesize a novel mechanism of wAIHA, that is proposed to be linked to the controversial subject of red blood cell senescence.

RECENT FINDINGS AND HYPOTHESES

It is now well established that band 3 on the red blood cell is the main target of autoantibodies in wAIHA. wAIHA targets the older red blood cells (RBCs) in about 80% of cases and, recently, it has been shown that the RBCs in these patients are aging faster than normal. It has been proposed that in these 80% of patients, that the autoantibody recognizes the senescent red blood cell antigen on band 3. It is further hypothesized that this autoantibody's production and potency has been exacerbated by hypersensitization to the RBC senescent antigen, which is processed through the adaptive immune system to create the pathogenic autoantibody. Recent publications have supported previous data that the senescent RBC antigen is exposed via a dynamic process, wherein oscillation of a band 3 internal loop flipping to the cell surface, creates a conformational neoantigen that is the RBC senescent antigen. It has also recently been shown that the cytokine profile in patients with wAIHA favors production of inflammatory cytokines/chemokines that includes interleukin-8 which can activate neutrophils to increase the oxidative stress on circulating RBCs to induce novel antigens, as has been postulated to favour exposure of the senescent RBC antigen.

SUMMARY

This manuscript reviews new findings and hypotheses regarding wAIHA and proposes a novel mechanism active in most wAIHA patients that is due to an exacerbation of normal RBC senescence.

Evans syndrome during pembrolizumab therapy for upper urinary tract cancer

Introduction

Immune checkpoint inhibitors are available for the treatment of advanced urothelial carcinoma; however, serious adverse events occasionally occur. Here, we report a rare case of Evans syndrome attributed to the use of an immune checkpoint inhibitor.

Case presentation

A 56-year-old man was diagnosed with left renal pelvic cancer and underwent left laparoscopic radical nephroureterectomy. Eight months postoperatively, computed tomography revealed para-aortic lymph node metastasis. Despite receiving chemotherapy, the disease progressed, and pembrolizumab was initiated. After 26 months of pembrolizumab treatment, the patient developed fever and anemia. Hematologic examination confirmed the diagnosis of Evans syndrome. He was treated with blood transfusions and corticosteroids, and gradual symptom improvement was observed.

Conclusion

This report highlights the potential risk of Evans syndrome associated with immune checkpoint inhibitor treatment. Clinicians should be aware of this possibility and consider early intervention with corticosteroids.

A 71-year-old male with a life-threatening recurrence of hemolytic anemia, thrombocytopenia, and acute kidney injury after pembrolizumab therapy: a case report

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, their use has been restricted in patients with preexisting autoimmune diseases due to concerns about increased risk of immune-related adverse events (irAEs).

CASE PRESENTATION

We present a case of a patient with stage IV lung adenocarcinoma and a history of complement-mediated autoimmune hemolytic anemia in remission. After receiving a single dose of pembrolizumab, the patient experienced life-threatening recurrent hemolytic anemia, de novo thrombocytopenia, diarrhea, myocarditis, and acute kidney injury. Laboratory tests confirmed the diagnosis of Evan's syndrome, with positive PAIgG and direct antiglobulin test. Treatment with intravenous methylprednisolone at a dose of 2 mg/kg resulted in a favorable response, with resolution of symptoms and rapid recovery of kidney function. The probable cause of pre-renal hypoperfusion (evidenced by a BUN-to-creatinine ratio of 48.1) leading to acute tubular injury was attributed to pembrolizumab-induced diarrhea.

CONCLUSIONS

This case illustrates a life-threatening recurrence of complement-mediated autoimmune hemolytic anemia induced by ICIs. Clinicians should carefully consider the expected efficacy and potential toxicity before initiating ICIs therapy in patients with preexisting autoimmune diseases. Additionally, the occurrence of acute kidney injury during ICIs therapy adds complexity and requires careful differential diagnosis.

Auto-immune hemolytic anemia and hemophagocytic lymphohistiocytosis as immune-related adverse event in patients with metastatic melanoma and concurrent chronic lymphocytic leukemia: a case series and literature review

Auto-immune hemolytic anemia (AIHA) and hemophagocytic lymphohistiocytosis (HLH) are both rare immune-related adverse events (irAEs) following treatment with immune checkpoint inhibitors. Consensus treatment guidelines are currently lacking. Patients with a solid malignancy and a concurrent lymphoproliferative disorder, such as chronic lymphocytic leukemia (CLL), might be more prone to develop hematological irAEs. We report the case history of two patients, diagnosed with CLL, who during treatment for metastatic melanoma with nivolumab, a PD-1 immune checkpoint blocking mAb, developed AIHA and HLH in combination with AIHA. Furthermore, we provide a review of the literature on published cases of immune-related AIHA and HLH and their correlation with CLL.

Case Report: Life-threatening pancytopenia with tislelizumab followed by cerebral infarction in a patient with lung adenocarcinoma

Immune checkpoint inhibitors (ICIs) are an integral antitumor therapy for many malignancies. Most patients show very good tolerability to ICIs; however, serious immune-related adverse events (irAEs) with ICIs have been well documented and prevent some patients from continuing ICIs or even become the direct cause of patient death. Cytopenia is a rare irAE but can be life-threatening. Here, we present the case of a 66-year-old male patient with metastatic lung adenocarcinoma who received two doses of chemotherapy + PD-1 antibody tislelizumab and developed pancytopenia after each dose. Although the first episode of pancytopenia resolved with a treatment regimen of granulocyte colony-stimulating factor (G-CSF), thrombopoietin (TPO), and red blood cell and platelet transfusion, the second episode showed extreme resistance to these treatments and improved only after the administration of steroids. His second pancytopenia episode resolved after a long course of treatment with methylprednisolone, G-CSF, TPO, hetrombopag and multiple red blood cell and platelet transfusions. However, he suffered a cerebral infarction when his platelet count was in the normal range and gradually recovered 1 week later. This case highlights the importance of the early recognition and management of hematological irAEs.

Synergistic immunotherapy targeting cancer-associated anemia: prospects of a combination strategy

Cancer-associated anemia promotes tumor progression, leads to poor quality of life in patients with cancer, and even obstructs the efficacy of immune checkpoint inhibitors therapy. However, the precise mechanism for cancer-associated anemia remains unknown and the feasible strategy to target cancer-associated anemia synergizing immunotherapy needs to be clarified. Here, we review the possible mechanisms of cancer-induced anemia regarding decreased erythropoiesis and increased erythrocyte destruction, and cancer treatment-induced anemia. Moreover, we summarize the current paradigm for cancer-associated anemia treatment. Finally, we propose some prospective paradigms to slow down cancer-associated anemia and synergistic the efficacy of immunotherapy. Video Abstract.

Vancomycin-Induced Hemolytic Anemia

Drug-induced hemolytic anemia is rare and can occur either by an immune-mediated mechanism or a non-immune-mediated mechanism. The drugs most frequently associated with immune-mediated hemolysis are penicillins and cephalosporins. It is usually difficult to distinguish drug-induced hemolysis from other more common causes of hemolysis; therefore, a high index of clinical suspicion is required to make the diagnosis. In this case report, we present a case of vancomycin-induced immune hemolytic anemia in a 75-year-old patient who developed hemolytic anemia after starting vancomycin for joint infection. Hematological parameters improved after the discontinuation of vancomycin. Mechanism and management of drug-induced immune hemolytic anemia are also reviewed in this report.

Positive direct antiglobulin tests in cancer patients on immune checkpoint inhibitors: A case series from India

Tumour cells activate immune checkpoints such as programmed death receptor-1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) signalling pathways to inhibit T lymphocyte activation and thus escape from immune surveillance. Immune checkpoint inhibitors (ICPis) reactivate T lymphocytes to recognize cancer cells by blocking CTLA-4 or PD-1. Autoimmune haemolytic anaemia is a rare, but often severe, complication of ICPis. Therefore, we performed a retrospective clinical case review, including serologic, haematology, and biochemistry laboratory results, of three patients who developed autoantibodies to erythrocytes following treatment with pembrolizumab, an anti-PD-1 inhibitor. Serologic testing of blood samples from these patients showed their red cells were positive for direct antiglobulin test (DAT+ for IgG in two cases and IgG with C3d in one case). Antibody detection test was negative. No patient had clinical and laboratory features of haemolysis. There were no additional immune-related adverse events. IgG antibodies coating red cells were neither IgG1 nor IgG3 in class and elution was found negative in all. In conclusion, immunohaematology laboratories should be aware of the possibility of erythroid autoantibodies and their nature in cancer patients receiving ICPis. The result of a positive DAT should be interpreted carefully in these patients to exclude other possible causes of anaemia.

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-Related Cytopenias: About 68 Cases from the French Pharmacovigilance Database

Simple Summary

Data on immune checkpoint inhibitor (ICI)-related cytopenias are scarce. The aim of the study was to further characterize grade ≥ 2 ICI-related cytopenias using the French pharmacovigilance database. Immune thrombocytopenia and autoimmune hemolytic anemia were the most frequently reported ICI-related cytopenias (50.7% and 25.3%, respectively). Nearly half were grade ≥ 4, and 4.4% of patients died from cytopenia-related complications. Using the French pharmacovigilance database, this study provides a comprehensive analysis of ICI-related cytopenias that are rare but potentially life-threatening adverse drug reactions. Early recognition and timely initiation of appropriate treatment are key in their management in clinical practice.

Abstract

Immune checkpoint inhibitor (ICI)-related cytopenias have been poorly described. This study aimed to further characterize ICI-related cytopenias, using the French pharmacovigilance database. All grade ≥ 2 hematological adverse drug reactions involving at least one ICI coded as suspected or interacting drug according to the World Health Organization criteria and reported up to 31 March 2022, were extracted from the French pharmacovigilance database. Patients were included if they experienced ICI-related grade ≥ 2 cytopenia. We included 68 patients (75 ICI-related cytopenias). Sixty-three percent were male, and the median age was 63.0 years. Seven patients (10.3%) had a previous history of autoimmune disease. Immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA) were the most frequently reported (50.7% and 25.3%, respectively). The median time to onset of ICI-related cytopenias was 2 months. Nearly half were grade ≥ 4, and three patients died from bleeding complications of refractory ITP and from thromboembolic disease with active AIHA. Out of 61 evaluable responses, complete or partial remission was observed after conventional treatment in 72.1% of ICI-related cytopenias. Among the 10 patients with ICI resumption after grade ≥ 2 ICI-related cytopenia, three relapsed. ICI-related cytopenias are rare but potentially life-threatening. Further studies are needed to identify risk factors of ICI-related cytopenias.

Hematologic cytopenia post CAR T cell therapy: Etiology, potential mechanisms and perspective

Chimeric Antigen-Receptor (CAR) T-cell therapies have shown dramatic efficacy in treating relapsed and refractory cancers, especially B cell malignancies. However, these innovative therapies cause adverse toxicities that limit the broad application in clinical settings. Hematologic cytopenias, one frequently reported adverse event following CAR T cell treatment, are manifested as a disorder of hematopoiesis with decreased number of mature blood cells and subdivided into anemia, thrombocytopenia, leukopenia, and neutropenia, which increase the risk of infections, fatigue, bleeding, fever, and even fatality. Herein, we initially summarized the symptoms, etiology, risk factors and management of cytopenias. Further, we elaborated the cellular and molecular mechanisms underlying the initiation and progression of cytopenias following CAR T cell therapy based on previous studies about acquired cytopenias. Overall, this review will facilitate our understanding of the etiology of cytopenias and shed lights into developing new therapies against CAR T cell-induced cytopenias.

Autoimmune hemolytic anemia: causes and consequences

INTRODUCTION

Autoimmune hemolytic anemia (AIHA) is classified according to the direct antiglobulin test (DAT) and thermal characteristics of the autoantibody into warm and cold forms, and in primary versus secondary depending on the presence of associated conditions.

AREAS COVERED

AIHA displays a multifactorial pathogenesis, including genetic (association with congenital conditions and certain mutations), environmental (drugs, infections, including SARS-CoV-2, pollution, etc.), and miscellaneous factors (solid/hematologic neoplasms, systemic autoimmune diseases, etc.) contributing to tolerance breakdown. Several mechanisms, such as autoantibody production, complement activation, monocyte/macrophage phagocytosis, and bone marrow compensation are implicated in extra-/intravascular hemolysis. Treatment should be differentiated and sequenced according to AIHA type (i.e. steroids followed by rituximab for warm, rituximab alone or in association with bendamustine or fludarabine for cold forms). Several new drugs targeting B-cells/plasma cells, complement, and phagocytosis are in clinical trials. Finally, thrombosis and infections may complicate disease course burdening quality of life and increasing mortality.

EXPERT OPINION

Beyond warm and cold AIHA, a gray-zone still exists including mixed and DAT negative forms representing an unmet need. AIHA management is rapidly changing through an increasing knowledge of the pathogenic mechanisms, the refinement of diagnostic tools, and the development of novel targeted and combination therapies.

Autoimmune hemolytic anemia in patients with relapsed Hodgkin's lymphoma after treatment with penpulimab, a monoclonal antibody against programmed death receptor-1

In August 2021, penpulimab, an anti-programmed cell death 1 (PD-1) monoclonal antibody, was approved in China for the treatment of adult patients with relapsed or refractory classic Hodgkin's lymphoma who completed at least second-line chemotherapy. Penpulimab is currently in clinical trials in China and Australia for the treatment of nasopharyngeal cancer and non-small cell lung cancer. Several clinical studies have shown that penpulimab is safe and effective, and no immune-related adverse events (irAEs) above grade 3 were observed. A 60-year-old woman with relapsed Hodgkin's lymphoma developed nausea and fatigue after receiving penpulimab monotherapy (200 mg every 2 weeks). Ten days after the second injection, the patient's condition worsened, and biochemical test results confirmed autoimmune hemolytic anemia (AIHA), with a hemoglobin level of 70 g/L (normal range, 115-150 g/L), an unconjugated bilirubin level of 19.08 µmol/L (normal range, 0-17 µmol/L), and positive direct antiglobulin test (DAT) results. On the same day, we treated her with prednisone (2 mg/kg), but her hemoglobin level continued to decline to 51 g/L one day after hormone therapy, so she received an intravenous infusion of washed red blood cells and underwent plasmapheresis, which eventually resolved the AIHA. Considering that the hemoglobin level was < 65 g/L and the irAE was grade 4, penpulimab was discontinued, and the symptoms of AIHA disappeared. From this event, we know that severe AIHA can occur after penpulimab use similar to other PD-1 antibodies. In this case, plasmapheresis showed a good therapeutic effect and should be used as a supplementary means when hormonal and immunosuppressive therapies cannot provide rapid symptom relief. In addition, we recommend regular direct antiglobulin testing, as well as haptoglobin, lactate dehydrogenase and other hemolysis-related laboratory tests, in patients prescribed penpulimab and similar drugs for the early diagnosis and treatment of AIHA.

Immunotherapy-associated Autoimmune Hemolytic Anemia

Over the past decade, the role of immunotherapy treatment in cancer has expanded; specifically, indications for immune checkpoint inhibitors (ICI) have multiplied and are used as first-line therapy. ICIs include cytotoxic T-lymphocyte-associated protein 4 and programmed cell death protein 1 inhibitors, as monotherapies or in combination. Autoimmune hemolytic anemia (AIHA) has emerged as a rare yet serious immune-related adverse event in ICI use. This review describes diagnosis and management of immunotherapy related AIHA (ir-AIHA) including an algorithmic approach based on severity of anemia. Suggested mechanisms are discussed, guidance on ICI resumption provided and prognosis reviewed including risk of recurrence.

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.

Nivolumab-Induced Autoimmune Haemolytic Anaemia and Safety of Subsequent Use of Ipilimumab: A Case Report

Autoimmune haemolytic anaemia (AIHA) is a rare immune-related adverse event and appears to be more common with anti-PD1/PDL1 than anti-CTLA4. Little is known about the safety of re-treating with anti-PD1/PDL1 or changing to anti-CTLA4. We present a case of grade 4 AIHA due to nivolumab (PD1-inhibitor) treatment in a patient with melanoma for adjuvant setting after surgery and the safeness of subsequent treatment with ipilimumab (anti-CTLA4). After the remission of AIHA with steroids, ipilimumab was started with the rationale of its different mechanism of action. Fortunately, AIHA did not recur. The mechanism by which checkpoint inhibitors cause AIHA is likely by augmenting or redirecting immune surveillance, especially by activating pre-existing red blood cell autoantibodies, but further studies must be done. To our knowledge, this is the first case published in the literature with the change of immunotherapy treatment to anti-CTLA4.

Hematologic complications of immune checkpoint inhibitors

Immune checkpoint inhibitors are a class of anti-neoplastic therapies that unleash immune cells to kill malignant cells. There are currently 7 medications FDA-approved for the treatment of 14 solid tumors and 2 hematological malignancies. These medications commonly cause immune-related adverse effects due to overactive T lymphocytes, autoantibody production, and/or cytokine dysregulation. Hematological toxicities are rare and of uncertain mechanism, and therefore management is often based on experiences with familiar conditions involving these perturbed immune responses, such as autoimmune hemolytic anemia, immune thrombocytopenia, and idiopathic aplastic anemia. Management is challenging because one must attend to the hematological toxicity while simultaneously attending to the malignancy, with the imperative that effective cancer therapy be maintained or minimally interrupted if possible. The purpose of this review is to assist clinicians by providing a clinical and pathophysiological framework in which to view these problems.

Pembrolizumab-induced autoimmune haemolytic anemia in a patient with chronic lymphocytic leukaemia successfully treated with ibrutinib

We present a unique case of a patient with a long-standing history of indolent chronic lymphocytic leukaemia (CLL) who suddenly developed autoimmune haemolytic anaemia after starting immune checkpoint inhibitor therapy for bladder cancer. He had no clear indication to start CLL-directed treatment based on current clinical practice guidelines; however, targeted treatment of CLL with ibrutinib proved to be effective in treating the haemolytic anaemia.

Diagnosis and management of cold agglutinin disease associated with low-grade B-cell lymphoma in a patient receiving pembrolizumab for lung cancer

A 65-year-old with non-small cell lung cancer developed autoimmune haemolytic anaemia while receiving pembrolizumab containing chemoimmunotherapy. Initially thought to be due to pembrolizumab induced haemolysis, he was treated with steroids, and pembrolizumab was held. Haemolysis was refractory to steroids and blood was observed to agglutinate in cold room temperatures. Cold agglutinins in high titre and monoclonal serum IgM kappa protein were detected. Bone marrow biopsy showed marginal zone lymphoma confirming low grade B-cell lymphoma causing cold agglutinin disease. B-cell depletion by rituximab stopped haemolysis, and pembrolizumab was safely continued for lung cancer.

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.

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.

Epigenomics and immunotherapeutic advances in pediatric brain tumors

Brain tumors are the leading cause of childhood cancer-related deaths. Similar to adult brain tumors, pediatric brain tumors are classified based on histopathological evaluations. However, pediatric brain tumors are often histologically inconsistent with adult brain tumors. Recent research findings from molecular genetic analyses have revealed molecular and genetic changes in pediatric tumors that are necessary for appropriate classification to avoid misdiagnosis, the development of treatment modalities, and the clinical management of tumors. As many of the molecular-based therapies developed from clinical trials on adults are not always effective against pediatric brain tumors, recent advances have improved our understanding of the molecular profiles of pediatric brain tumors and have led to novel epigenetic and immunotherapeutic treatment approaches currently being evaluated in clinical trials. In this review, we focus on primary malignant brain tumors in children and genetic, epigenetic, and molecular characteristics that differentiate them from brain tumors in adults. The comparison of pediatric and adult brain tumors highlights the need for treatments designed specifically for pediatric brain tumors. We also discuss the advancements in novel molecularly targeted drugs and how they are being integrated with standard therapy to improve the classification and outcomes of pediatric brain tumors in the future.

Increased Incidence of Venous Thromboembolism with Cancer Immunotherapy

BACKGROUND

Cancer immunotherapy is associated with several immune-related adverse events, but the relationship between immunotherapy and venous thromboembolism has not been thoroughly studied.

METHODS

We conducted a retrospective cohort study of 1,686 patients who received immunotherapy for a variety of malignancies to determine the incidence of venous thromboembolism and the impact of venous thromboembolism on survival. To examine the potential role of inflammation in venous thromboembolism, we also profiled immune cells and plasma cytokines in blood samples obtained prior to initiation of immunotherapy in a sub-cohort of patients treated on clinical trials who subsequently did (N = 15), or did not (N = 10) develop venous thromboembolism.

FINDINGS

Venous thromboembolism occurred while on immunotherapy in 404/1686 patients (24%) and was associated with decreased overall survival [HR=1.22 (95% CI 1.06-1.41), p<0.008]. Patients that developed venous thromboembolism had significantly higher pretreatment levels of myeloid-derived suppressor cells (5.382 ± 0.873 vs. 3.341 ± 0.3402, mean ± SEM; p=0.0045), interleukin 8 (221.2 ± 37.53 vs. 111.6 ± 25.36, mean ± SEM; p=0.016), and soluble vascular cell adhesion protein 1 (1210 ± 120.6 vs. 895.5 ± 53.34, mean ± SEM; p=0.0385).

CONCLUSIONS

These findings demonstrate that venous thromboembolism is an underappreciated and important immune-related adverse event associated with cancer immunotherapy, and may implicate an interleukin 8 and myeloid-derived suppressor cell-driven pathway in pathogenesis.

Autoimmune Complications in Hematologic Neoplasms

Autoimmune cytopenias (AICy) and autoimmune diseases (AID) can complicate both lymphoid and myeloid neoplasms, and often represent a diagnostic and therapeutic challenge. While autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP) are well known, other rarer AICy (autoimmune neutropenia, aplastic anemia, and pure red cell aplasia) and AID (systemic lupus erythematosus, rheumatoid arthritis, vasculitis, thyroiditis, and others) are poorly recognized. This review analyses the available literature of the last 30 years regarding the occurrence of AICy/AID in different onco-hematologic conditions. The latter include chronic lymphocytic leukemia (CLL), lymphomas, multiple myeloma, myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), myeloproliferative neoplasms, and acute leukemias. On the whole, AICy are observed in up to 10% of CLL and with higher frequencies in certain subtypes of non-Hodgkin lymphoma, whilst they occur in less than 1% of low-risk MDS and CMML. AID are described in up to 30% of myeloid and lymphoid patients, including immune-mediated hemostatic disorders (acquired hemophilia, thrombotic thrombocytopenic purpura, and anti-phospholipid syndrome) that may be severe and fatal. Additionally, AICy/AID are found in about 10% of patients receiving hematopoietic stem cell transplant or treatment with new checkpoint inhibitors. Besides the diagnostic difficulties, these AICy/AID may complicate the clinical management of already immunocompromised patients.

Pembrolizumab-related autoimmune hemolytic anemia in a patient with metastatic lung adenocarcinoma

Immune checkpoint inhibitors (ICIs) have become the main drugs for programmed cell death receptor-1 or ligand-1 expressing non-small cell lung cancer (NSCLC) combined with conventional chemotherapy. ICIs are generally more tolerable than cytotoxic chemotherapies in terms of toxicity, and ICI-related adverse events are mild and manageable. However, these drugs may lead to unexpected severe adverse events such as immune-related hematologic toxicities, which could be life-threatening. Here, a rare case of a pembrolizumab-related adverse event in a patient with NSCLC who showed early-onset hemolytic anemia and recovered by high-dose steroid and a series of plasma exchanges is reported.

Hematological immune related adverse events after treatment with immune checkpoint inhibitors

INTRODUCTION

With the increasing use of checkpoint inhibitors, rare immune-related adverse events (irAE) are being identified. Haematological irAE (hem-irAE) are difficult to treat and have shown high mortality rates. In order to improve side-effect management for these potentially life-threatening events, we analysed frequency, severity and outcomes.

PATIENTS AND METHODS

Patients who developed hem-irAE while being treated with immune checkpoint inhibitors (ICI) therapy were retrospectively identified from 18 international cancer centres.

RESULTS

In total, more than 7626 patients treated with ICI were screened, and 50 patients with hem-irAE identified. The calculated incidence amounts to 0.6% and median onset was 6 weeks after the ICI initiation (range 1-128 weeks). Thrombocytopenia and leucopaenia were the most frequent hem-irAE with 34% (17/50) and 34% (17/50), respectively, followed by anaemia 28% (14/50), hemophagocytic lymphohistiocytosis (4% (2/50)), aplastic anaemia (2% (1/50)), acquired haemophilia A (2% (1/50)) and coagulation deficiency (2% (1/50)). Simultaneous thrombocytopenia and neutropenia occurred in two patients, concurrent anaemia and thrombocytopenia in one patient. Other than cessation of ICI (in 60%) and corticosteroids (in 78%), treatment included second-line immunosuppression in 24% of cases. Events resolved in 78% (39/50), while 18% (9/50) had persistent changes, and 2% (1/50) had fatal outcomes (agranulocytosis).

CONCLUSION

Hem-irAE can affect all haematopoietic blood cell lineages and may persist or even be fatal. Management may require immunosuppression beyond corticosteroids. Although these irAE are rare, treating physicians should be aware, monitor blood counts regularly and promptly act upon detection.

Bosentan-induced immune hemolytic anemia in 17 years old man. A case report

Hemolytic anemia is a very important immune-mediated reaction, which its late diagnosis can be fatal. Medications along with other causes can induce hemolytic anemia. Drug induced immune hemolytic anemia (DIIHA) is caused by the development of autoantibodies. Accordingly, DIIHA is rare and there is not enough data for its prevalence. Number of drugs that can cause DIIHA have increased in recent decades. A 17-year-old man who had congenital single ventricle heart (CHB) and pulmonary artery hypertension (PAH) was admitted at Imam Khomeini hospital complex affiliated to Tehran University of Medical Sciences, with chief complaint of jaundice and icter. Bosentan and Tadalafil were in the list of the drugs used by this patient. Although both drugs were recommended to be discontinued in the patient, in the course of hospitalization, the patient accidentally continued to take his Tadalafil. However, the patient's recovery continued. Given that the patient's Coombs test was positive, his hemolytic anemia mechanism was drug-induced immune-mediated hemolytic anemia. As a result, according to Naranjo score = 6, Bosentan was considered as the main possible culprit to induce DIIHA in this patient. Following the discontinuation of Bosentan and receiving Prednisolone, the patient's clinical symptoms and laboratory parameters resolved and the patient was then discharged.

Rituximab Use in Warm and Cold Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia is a rare condition characterized by destruction of red blood cells with and without involvement of complement. It is associated with significant morbidity and mortality. In warm autoimmune hemolytic anemia, less than 50% of patients remain in long-term remission following initial steroid therapy and subsequent therapies are required. Cold agglutinin disease is a clonal hematologic disorder that requires therapy in the majority of patients and responds poorly to steroids and alkylators. Rituximab has a favorable toxicity profile and has demonstrated efficacy in autoimmune hemolytic anemia in first-line as well as relapsed settings. Rituximab is the preferred therapy for steroid refractory warm autoimmune hemolytic anemia (wAIHA) and as part of the first- and second-line treatment of cold agglutinin disease. This article reviews the mechanism of action of rituximab and the current literature on its role in the management of primary and secondary warm autoimmune hemolytic anemia and cold agglutinin disease.

Difficult Cases of Autoimmune Hemolytic Anemia: A Challenge for the Internal Medicine Specialist

Autoimmune hemolytic anemia (AIHA) is diagnosed in the presence of anemia, hemolysis, and direct antiglobulin test (DAT) positivity with monospecific antisera. Many confounders of anemia and hemolytic markers should be included in the initial workup (i.e., nutrients deficiencies, chronic liver or kidney diseases, infections, and cancers). Besides classical presentation, there are difficult cases that may challenge the treating physician. These include DAT negative AIHA, diagnosed after the exclusion of other causes of hemolysis, and supported by the response to steroids, and secondary cases (infections, drugs, lymphoproliferative disorders, immunodeficiencies, etc.) that should be suspected and investigated through careful anamnesis physical examination, and specific tests in selected cases. The latter include autoantibody screening in patients with signs/symptoms of systemic autoimmune diseases, immunoglobulins (Ig) levels in case of frequent infections or suspected immunodeficiency, and ultrasound/ computed tomography (CT) studies and bone marrow evaluation to exclude hematologic diseases. AIHA occurring in pregnancy is a specific situation, usually manageable with steroids and intravenous (iv) Ig, although refractory cases have been described. Finally, AIHA may complicate specific clinical settings, including intensive care unit (ICU) admission, reticulocytopenia, treatment with novel anti-cancer drugs, and transplant. These cases are often severe, more frequently DAT negative, and require multiple treatments in a short time.

New Insights in Autoimmune Hemolytic Anemia: From Pathogenesis to Therapy Stage 1

Autoimmune hemolytic anemia (AIHA) is a highly heterogeneous disease due to increased destruction of autologous erythrocytes by autoantibodies with or without complement involvement. Other pathogenic mechanisms include hyper-activation of cellular immune effectors, cytokine dysregulation, and ineffective marrow compensation. AIHAs may be primary or associated with lymphoproliferative and autoimmune diseases, infections, immunodeficiencies, solid tumors, transplants, and drugs. The direct antiglobulin test is the cornerstone of diagnosis, allowing the distinction into warm forms (wAIHA), cold agglutinin disease (CAD), and other more rare forms. The immunologic mechanisms responsible for erythrocyte destruction in the various AIHAs are different and therefore therapy is quite dissimilar. In wAIHA, steroids represent first line therapy, followed by rituximab and splenectomy. Conventional immunosuppressive drugs (azathioprine, cyclophosphamide, cyclosporine) are now considered the third line. In CAD, steroids are useful only at high/unacceptable doses and splenectomy is uneffective. Rituximab is advised in first line therapy, followed by rituximab plus bendamustine and bortezomib. Several new drugs are under development including B-cell directed therapies (ibrutinib, venetoclax, parsaclisib) and inhibitors of complement (sutimlimab, pegcetacoplan), spleen tyrosine kinases (fostamatinib), or neonatal Fc receptor. Here, a comprehensive review of the main clinical characteristics, diagnosis, and pathogenic mechanisms of AIHA are provided, along with classic and new therapeutic approaches.

Multidisciplinary Clinical Approach to Cancer Patients with Immune-Related Adverse Events Induced by Checkpoint Inhibitors

Immune-oncology is a major breakthrough in cancer treatment and has become the standard of care for a wide variety of solid organ malignancies. Unfortunately, manipulation of the immune system with checkpoint inhibitors may result in an immune-based attack of normal tissues which can lead to treatment discontinuation. These immune-related adverse events (irAEs) are diverse and affect several organs, constituting a new clinical challenge in the management of cancer patients. The complexity of this scenario requires a multidisciplinary approach that allows the early identification, diagnosis and treatment of specific irAE, ruling out other non-related adverse events. Hospital Clinic has a multidisciplinary team seeking to develop a coordinated strategy to facilitate the access of patients with suspected irAEs to specialised care resulting in harmonised management that guarantees the best patient care. The aim of the manuscript was to describe the current evidence on the management of irAEs reflecting a coordinated multidisciplinary approach to face this clinical challenge regardless of the immunotherapy indication.

Severe mesenteric ischemia with multiple organ failure in a patient previously treated with a humanized monoclonal antibody against programmed death receptor-1 (pembrolizumab), a case of pembrolizumab associated catastrophic antiphospholipid syndrome?

Immune checkpoint inhibitors are used in the treatment of different types of tumors including melanoma and non-small cell lung carcinoma. The use of these inhibitors is associated with a broad spectrum of immune-related adverse effects. Here we report a case of a patient admitted to the intensive care unit with multiple organ failure due to catastrophic antiphospholipid syndrome following treatment with pembrolizumab, an immune checkpoint inhibitor, because of metastatic melanoma. The presented patient had multiple organ failure of lung, gastro-intestinal, renal, and the liver. Vascular thrombosis was confirmed by both imaging (pulmonary embolism on computed tomography–thorax) and histopathological examination of the intestines. In combination with the presence of IgA anti-cardiolipin antibodies and initially IgM anti-cardiolipin antibodies, catastrophic antiphospholipid syndrome was suspected. Despite treatment with plasmapheresis and corticosteroids, the patient died due to multiple organ failure. Catastrophic antiphospholipid syndrome is difficult to recognize and has high mortality rates despite supportive treatment. In this case report, discussion is provided regarding the possible immunological mechanism behind catastrophic antiphospholipid syndrome during or after treatment with immune checkpoint inhibitors. It is important to realize that in modern intensive care unit, more patients with immune-related adverse effects of the treatment with immune checkpoint inhibitors will be admitted, because of an increase in the number of patients treated with these checkpoint inhibitors. When these patients are admitted on the intensive care unit, multi-disciplinary consultation is important because of the difficulty of early recognition and optimal treatment of these possible lethal side effects.

Atezolizumab-induced hemolytic anemia - A case report

INTRODUCTION

Atezolizumab is currently the only immunotherapy used in conjunction with nab-paclitaxel for locally advanced or triple negative breast cancer. Limited data is available regarding hemolytic anemia as a side effect of atezolizumab.

CASE REPORT

We describe a 59-year-old female with a history of triple negative breast cancer with bone metastases presenting for follow up on Cycle 1, Day 15 of atezolizumab and nab-paclitaxel (100 mg/m²). Patient's complete blood count (CBC) showed macrocytic anemia, with further workup significant for autoimmune hemolytic anemia (AIHA) attributed to atezolizumab.Management and outcome: Patient was started on a high dose prednisone taper starting at 80 mg daily for 16 days, folic acid 1 mg three times daily, iron sucrose, and darbepoetin alfa. Patient's counts recovered, and she was able to start Cycle 2 and continued through Cycle 10 without any additional pre-medications.

DISCUSSION

Hemolytic anemia induced by atezolizumab is a rare side effect that was successfully treated in this patient with a prednisone taper.

Pembrolizumab-Induced Cold Agglutinin Disease

BACKGROUND The introduction of immunotherapy in the management of metastatic lung cancer appears to be changing their natural history. Most patients tolerate immunotherapy without any significant adverse events. Nevertheless, a significant number of patients still experience adverse effects. Autoimmune hemolytic anemia has been described as mostly related to warm autoantibodies. The following case report describes cold agglutinin disease with hemolysis secondary to Pembrolizumab therapy for the treatment of metastatic lung cancer. CASE REPORT A 58-year-old woman noted a left neck mass 4 months prior to her presentation. A biopsy confirmed the presence of metastatic adenocarcinoma, consistent with primary lung cancer. Further evaluation revealed the tumor to be PDL-1-positive. She was started on Pembrolizumab, Pemetrexed, and carboplatin chemotherapy regimen. Her CBC was within normal limits when she started therapy, but within 4 weeks hemoglobin dropped to 4.3 g/dL. Further evaluation showed high cryoglobulin levels and a high cold agglutinin titer. Complement C3 DAT was positive. A peripheral smear showed clumps of red cells and the serum IgM was elevated. The diagnosis of CAD was made. She was then started on Rituximab. Imaging showed a significant response, with decreased disease burden. CONCLUSIONS Our case shows a unique presentation of CAD, initially presumed to be myelosuppression secondary to chemotherapy. Instead, a peripheral smear revealed Pembrolizumab to be the cause of cold agglutinin disease. Due to the relatively unknown association between these 2 entities, patient care was delayed. Finally, after initiation of Rituximab therapy, the patient's CBC began to recover.

Lessons to be Learnt from Real-World Studies on Immune-Related Adverse Events with Checkpoint Inhibitors: A Clinical Perspective from Pharmacovigilance

The advent of immune checkpoint inhibitors (ICIs) caused a paradigm shift both in drug development and clinical practice; however, by virtue of their mechanism of action, the excessively activated immune system results in a multitude of off-target toxicities, the so-called immune-related adverse events (irAEs), requiring new skills for timely diagnosis and a multidisciplinary approach to successfully manage the patients. In the recent past, a plethora of large-scale pharmacovigilance analyses have characterized various irAEs in terms of spectrum and clinical features in the real world. This review aims to summarize and critically appraise the current landscape of pharmacovigilance studies, thus deriving take-home messages for oncologists. A brief primer to study design, conduction, and data interpretation is also offered. As of February 2020, 30 real-world postmarketing studies have characterized multiple irAEs through international spontaneous reporting systems, namely WHO Vigibase and the US FDA Adverse Event Reporting System. The majority of studies investigated a single irAE and provided new epidemiological evidence about class-specific patterns of irAEs (i.e. anti-cytotoxic T-lymphocyte antigen 4 [CTLA-4] versus anti-programmed cell death 1 [PD-1] receptor, and its ligand [PD-L1]), kinetics of appearance, co-occurrences (overlap) among irAEs, and fatality rate. Oncologists should be aware of both strengths and limitations of these pharmacovigilance analyses, especially in terms of data interpretation. Optimal management (including rechallenge), predictivity of irAEs (as potential biomarkers of effectiveness), and comparative safety of ICIs (also in terms of combination regimens) represent key research priorities for next-generation real-world studies.