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

Pembrolizumab-induced agranulocytosis

INTRODUCTION

With the widespread use of anti-programmed death-1 monoclonal antibodies, such as pembrolizumab, rare side effects appear in clinical practice.

CASE REPORT

We report the case of a man diagnosed with non-keratinizing squamous lung carcinoma stage IVB with programmed death-ligand 1 70% who developed agranulocytosis 10 days after a single dose of pembrolizumab as monotherapy.

MANAGEMENT AND OUTCOME

Pembrolizumab was discontinued immediately. Grade 4 neutrophil decrease is mentioned in the product information sheet as a rare side effect. The patient was admitted in poor physical condition with grade 4 neutropenic fever, mucositis and anemia. Agranulocytosis did not improve despite treatment with granulocyte colony-stimulating factor, intravenous corticosteroids and intravenous immunoglobulins. He experienced a rapid worsening and died 3 weeks after admission. The causal relationship between pembrolizumab and the appearance of agranulocytosis was determined as possible according to Naranjo's modified Karch and Lasagna's imputability algorithm.

DISCUSSION

Hematologic immune-related adverse events are uncommon but important side effects among patients treated with immune checkpoint inhibitors. Agranulocytosis and neutropenia are infrequently reported but can be life-threatening. The main approach for agranulocytosis consists of intravenous corticosteroids, granulocyte colony-stimulating factors and blood products. Depending on bone marrow characteristics, treatments for refractory patients include intravenous immunoglobulins or cyclosporine. After an immune-related adverse event, benefits and risks must be considered before continuation with an immune checkpoint inhibitor. Detection and communication of adverse drug reactions to the Pharmacovigilance Systems have special relevance for rare side effects.

Pure Red Cell Aplasia and Chromosomal Abnormality in a Patient With Lung Adenocarcinoma Receiving Immune Checkpoint Inhibitors: A Case Report

BACKGROUND/AIM

Immune checkpoint inhibitors can induce immune-related adverse events in various organs, thus careful observation is required.

CASE REPORT

A 69-year-old man was diagnosed with advanced lung adenocarcinoma and treated with combined therapy of carboplatin plus pemetrexed plus pembrolizumab. After two cycles of treatment, anemia was noted. Myelosuppression due to cytotoxic anticancer agents was suspected and the cytotoxic agents were discontinued, followed by three courses of pembrolizumab monotherapy. However, the anemia persisted, requiring red blood cell transfusions. A bone marrow biopsy revealed erythroblast hypoplasia and chromosomal abnormalities, resulting in a diagnosis of pure red cell aplasia. These adverse events were considered immune-related because of the treatment history with an immune checkpoint inhibitor, and 60 mg/day (1 mg/kg/day) of prednisolone was initiated. Anemia improved, and it did not recur during the tapering of prednisolone.

CONCLUSION

Immune-related pure red cell aplasia should be considered for patients presenting anemia during treatment with immune checkpoint inhibitors.

Immune-Related Adverse Events Due to Cancer Immunotherapy: Immune Mechanisms and Clinical Manifestations

The landscape of cancer treatment has undergone a significant transformation with the introduction of Immune Checkpoint Inhibitors (ICIs). Patients undergoing these treatments often report prolonged clinical and radiological responses, albeit with a potential risk of developing immune-related adverse events (irAEs). Here, we reviewed and discussed the mechanisms of action of ICIs and their pivotal role in regulating the immune system to enhance the anti-tumor immune response. We scrutinized the intricate pathogenic mechanisms responsible for irAEs, arising from the evasion of self-tolerance checkpoints due to drug-induced immune modulation. We also summarized the main clinical manifestations due to irAEs categorized by organ types, detailing their incidence and associated risk factors. The occurrence of irAEs is more frequent when ICIs are combined; with neurological, cardiovascular, hematological, and rheumatic irAEs more commonly linked to PD1/PD-L1 inhibitors and cutaneous and gastrointestinal irAEs more prevalent with CTLA4 inhibitors. Due to the often-nonspecific signs and symptoms, the diagnosis of irAEs (especially for those rare ones) can be challenging. The differential with primary autoimmune disorders becomes sometimes intricate, given the clinical and pathophysiological similarities. In conclusion, considering the escalating use of ICIs, this area of research necessitates additional clinical studies and practical insights, especially the development of biomarkers for predicting immune toxicities. In addition, there is a need for heightened education for both clinicians and patients to enhance understanding and awareness.

Sarcoid-like reaction and hypothyroidism induced by PD-1 inhibitor treatment in metastatic renal cell carcinoma: a case report and literature review

BACKGROUND

Pembrolizumab is among the approved treatments for a variety of cancer types, including clear cell renal cell carcinoma (ccRCC). It has contributed to enhancing the prognosis of renal cell carcinoma. However, it is essential to be aware of the numerous potential immune-related side effects associated with its use.

CASE PRESENTATION

A 69-year-old patient with a history of metastatic renal cell carcinoma has been undergoing treatment with Pembrolizumab, an immune checkpoint inhibitor. The medication has led to the development of a sarcoid-like reaction, initially misinterpreted as cancer recurrence and progression. Additionally, the patient has experienced new-onset hypothyroidism, which has been attributed to the immunotherapy.

CONCLUSION

Clinicians, including oncologists, endocrinologists, and radiologists, should maintain a high level of suspicions and awareness regarding the potential adverse events associated with newly introduced immunotherapies like pembrolizumab. This knowledge is crucial for the accurate diagnosis and appropriate management of patients receiving these treatments.

Real-world evidence of incidence and outcomes of aplastic anaemia following administration of immune checkpoint inhibitors

Aplastic anaemia (AA) is a rare immune-related adverse events (irAEs) after immune checkpoint inhibitors (ICIs) administration with poorly understood incidence and outcomes. We analysed an electronic health record database of 52 303 ICI-treated patients and found 77 (0.15%) cases of AA, with a median onset of 126 days (interquartile range, 58-363 days). The most used treatment for AA was systemic glucocorticoids 60 (77.9%) and 32 (41.6%) patients were able to resume ICI within 1 year. Patients diagnosed with AA had a steep decline in overall survival (OS) within the first 120 days; when compared to propensity score-matched patients without AA, they had a significantly worse OS (hazard ratio 1.72, 95% confidence interval 1.19-2.50; p = 0.003).

Immune checkpoint inhibitor-induced aplastic anaemia: Case series and large-scale pharmacovigilance analysis

Introduction: Impressive advances in immunotherapy especially immune checkpoint inhibitors have made great progress in treating multiple cancers but can also cause serious even incurable immune-related adverse events, mostly found in colitis, dermatitis, hepatitis, and thyroiditis patients. Rare autoimmune hematologic toxicities have been reported in the literature, but are poorly described. Aplastic anaemia induced by immune checkpoint inhibitors is a life-threatening autoimmune disease; however, only a few cases have been reported in the literature. Objective: To characterize and evaluate Aplastic anaemia associated with different ICI regimens in public database and review the literature. Methods: We described a case series of patients experiencing Aplastic anaemia while on immune checkpoint inhibitors. We also mined the Food and Drug Administration's Adverse Event Reporting System and used reporting odds ratio, the proportional reporting ratio, the Bayesian confidence propagation neural network and the multi-item gamma Poisson shrinker algorithms to achieve the data of the suspected adverse events of Aplastic anaemia-induced by immune checkpoint inhibitors between January 2011 and June 2022. Results: Thirteen patients with Aplastic anaemia events while on immune checkpoint inhibitors were included in our case series, and seven of them had a fatal outcome. In FAERS, a total of 38 individual case safety reports (immune checkpoint inhibitors) with different ICI regimens were retrieved, of which 25 (65.79%) were reported as monotherapy and 13 (34.2%) had a fatal outcome. The reporting odds ratio was significant for nivolumab (reporting odds ratio 3.05, 95%CI 1.73-5.38), pembrolizumab (reporting odds ratio 2.33, 95%CI 1.16-4.67), avelumab (reporting odds ratio 12.63, 95%CI 3.15-50.62) and ipilimumab/nivolumab (ROR 2.57, 95%CI 1.15-5.72). Conclusion: There is a significant reporting signal of Aplastic anaemia with several ICI agents. Clinicians should raise awareness and monitor this potentially fatal adverse event.

Associations Between Immune-Related Venous Thromboembolism and Efficacy of Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

This study aims to summarize the available data and determine if the presence of venous thromboembolism (VTE) immune-related adverse event (irAE) in patients with immune checkpoint inhibitor (ICI) therapy is associated with improved treatment efficacy and clinical outcomes, which in turn was used to help optimize patient selection for anticoagulation therapy and inform rational treatment strategies for overcoming the mechanisms of ICI resistance. PubMed, Embase, Web of Science, and Cochrane Library were searched up to March 18, 2023, for studies assessing the relationship between VTE irAE development during ICI therapy and cancer outcomes. Seven primary articles with a total of 4437 patients were included in the overall survival (OS) meta-analysis. Patients with VTE had a significant increase in overall mortality compared to patients without VTE in adjusted hazard ratios (HRs 1.36, 95% confidence interval [CI] 1.06-1.75, P  =  .02). In the studies where immortal time bias (ITB) was accounted for, patients with VTE irAE also had poor OS than those without. HR and the corresponding 95% CI values in the non-ITB group were 2.53 (1.75-3.66, P < .00001) with low heterogeneity (P  =  .17, I2  =  48%) and 1.21 (1.06-1.37, P  =  .004) in the ITB group with no heterogeneity (P  =  .95, I2  =  0%), respectively. Despite the heterogeneity identified, the evidence does suggest that VTE irAE occurrence could be served as a prognostic indicator, with higher frequencies of occurrence associated with poorer OS. However, the fundamental role of this association with clinical consequences should be further investigated in large cohorts and clinical trials.

Pembrolizumab-Induced Rhabdomyolysis in a Clear Cell Renal Cell Carcinoma Patient: A Case Report

Pembrolizumab is one of the approved treatments for many types of cancer including clear cell renal cell carcinoma (ccRCC). It has improved the prognosis of renal cell carcinoma, yet has many possible immune-related side effects. We discuss a rare case of rhabdomyolysis in an ccRCC patient treated with pembrolizumab. The case was complicated with acute kidney injury and severe hypothyroidism, which can be attributed to pembrolizumab.

Successful Steroid Treatment of Pembrolizumab-induced Agranulocytosis that Developed after Splenectomy in a Patient with Non-small-cell Lung Cancer: A Case Report

Neutropenia, a rare immune-related adverse event, affects patients receiving treatment with immune checkpoint inhibitors (ICIs). We herein report a case of pembrolizumab-induced agranulocytosis. An 83-year-old man was diagnosed with advanced-stage lung carcinoma concomitant with splenomegaly complicated by hypersplenism, causing pancytopenia. To avoid the risk of bone marrow suppression due to cytotoxic chemotherapy, pembrolizumab monotherapy was chosen. However, the patient developed agranulocytosis despite the resolution of pancytopenia through splenectomy performed after the fourth pembrolizumab cycle. Neutrophil counts improved after steroid treatment but not after granulocyte colony-stimulating factor treatment. This case demonstrated that neutropenia can sometimes develop abruptly after several ICI therapy cycles.

Chidamide plus Tyrosine Kinase Inhibitor Remodel the Tumor Immune Microenvironment and Reduce Tumor Progression When Combined with Immune Checkpoint Inhibitor in Naïve and Anti-PD-1 Resistant CT26-Bearing Mice

Combined inhibition of vascular endothelial growth factor receptor (VEGFR) and the programmed cell death protein 1 (PD-1) pathways has shown efficacy in multiple cancers; however, the clinical outcomes show limited benefits and the unmet clinical needs still remain and require improvement in efficacy. Using murine colon carcinoma (CT26) allograft models, we examined the efficacy and elucidated novel tumor microenvironment (TME) remodeling mechanisms underlying the combination of chidamide (a benzamide-based class l histone deacetylase inhibitor; brand name in Taiwan, Kepida^®) with VEGF receptor tyrosine kinase inhibitor (TKIs; cabozantinib/regorafenib, etc.) and immune checkpoint inhibitors (ICIs; anti-PD-1/anti-PD-L1/anti-CTLA-4 antibodies). The TME was assessed using flow cytometry and RNA-sequencing to determine the novel mechanisms and their correlation with therapeutic effects in mice with significant treatment response. Compared with ICI alone or cabozantinib/regorafenib + ICI, combination of chidamide + cabozantinib/regorafenib + ICI increased the tumor response and survival benefits. In particular, treatment of CT26-bearing mice with chidamide + regorafenib + anti-PD-1 antibody showed a better objective response rate (ORR) and overall survival (OS). Similar results were observed in anti-PD-1 treatment-resistant mice. After treatment with this optimal combination, in the TME, RNA-sequencing revealed that downregulated mRNAs were correlated with leukocyte migration, cell chemotaxis, and macrophage gene sets, and flow cytometry analysis showed that the cell numbers of myeloid-derived polymorphonuclear suppressor cells and tumor-associated macrophages were decreased. Accordingly, chidamide + regorafenib + anti-PD-1 antibody combination therapy could trigger a novel TME remodeling mechanism by attenuating immunosuppressive cells, and restoring T-cell activation to enhance ORR and OS. Our studies also showed that the addition of Chidamide to the regorafenib + anti-PD-1 Ab combination could induce a durable tumor-specific response by attenuating immune suppression in the TME. In addition, this result suggests that TME remodeling, mediated by epigenetic immunomodulator combined with TKI and ICI, would be more advantageous for achieving a high objective response rate, when compared to TKI plus ICI or ICI alone, and maintaining long-lasting antitumor activity.

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.

Plasma Exchange for Severe Immune-Related Adverse Events from Checkpoint Inhibitors: An Early Window of Opportunity?

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several advanced malignancies leading to durable remission in a subset of patients. Their rapidly expanding use has led to an increased frequency of immune-related adverse events (irAEs). The pathogenesis of irAEs is poorly understood but may involve aberrant activation of T cells leading to inflammatory cytokine release or production of pathogenic antibodies leading to organ damage. Severe irAEs can be extremely debilitating and, in some cases, life threatening. IrAEs may not always be corticosteroid responsive or may require excessively high, often toxic, corticosteroid doses. Therapeutic plasma exchange (PLEX) is a treatment modality that has shown promising results for the management of certain severe irAEs, including irAEs that are not mentioned in current treatment guidelines. PLEX may attenuate ongoing irAEs and prevent delayed irAEs by accelerating clearance of the ICI, or by acutely removing pathogenic antibodies, cytokines, and chemokines. Here, we summarize examples from the literature in which PLEX was successfully used for the treatment of irAEs. We posit that timing may be a critical factor and that earlier utilization of PLEX for life-threatening irAEs may result in more favorable outcomes. In individuals at high risk for irAEs, the availability of PLEX as a potential therapeutic mitigation strategy may encourage life-saving ICI use or rechallenge. Future research will be critical to better define which indications are most amenable to PLEX, particularly to establish the optimal place in the sequence of irAE therapies and to assess the ramifications of ICI removal on cancer outcomes.

Safety of Immune Checkpoint Inhibitor Resumption after Interruption for Immune-Related Adverse Events, a Narrative Review

Immune checkpoint inhibitors (ICIs) have become the standard of care for several types of cancer due to their superiority in terms of survival benefits in first- and second-line treatments compared to conventional therapies, and they present a better safety profile (lower absolute number of grade 1-5 adverse events), especially if used in monotherapy. However, the pattern of ICI-related adverse events is totally different, as they are characterized by the development of specific immune-related adverse events (irAEs) that are unique in terms of the organs involved, onset patterns, and severity. The decision to resume ICI treatment after its interruption due to irAEs is challenged by the need for tumor control versus the risk of occurrence of the same or different irAEs. Studies that specifically assess this point remain scarce, heterogenous and mostly based on small samples of patients or focused only on the recurrence rate of the same irAE after ICI resumption. Moreover, patients with grade ≥3 irAEs were excluded from many of these studies. Herein, we provide a narrative review on the field of safety of ICI resumption after interruption due to irAE(s).

Understanding neutropenia secondary to intrinsic or iatrogenic immune dysregulation

As a key member of the innate and adaptive immune response, neutrophils provide insights into the hematopoietic and inflammatory manifestations of inborn errors of immunity (IEI) and the consequences of immunotherapy. The facile recognition of IEI presenting with neutropenia provides an avenue for hematologists to facilitate early diagnosis and expedite biologically rationale care. Moreover, enhancing the understanding of the molecular mechanisms driving neutropenia in IEI-decreased bone marrow reserves, diminished egress from the bone marrow, and decreased survival-offers an opportunity to further dissect the pathophysiology driving neutropenia secondary to iatrogenic immune dysregulation, eg, immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy.

Organ-specific Adverse Events of Immune Checkpoint Inhibitor Therapy, with Special Reference to Endocrinopathies

Immune checkpoint inhibitors are potent and promising immunotherapeutic agents that are increasingly used for the management of various types of advanced cancers. The widespread approval of this group of drugs simultaneously revealed immune-related adverse events as unique side-effects. Endocrinopathies are one of the most common immune-related adverse events. The precise pathogenic mechanisms for these endocrinopathies are still unclear. Though few of the endocrinopathies are reversible, calling for only symptom control, most are irreversible, requiring multiple long-term hormone replacement therapies. However, in contrast to other organ-specific immune-related adverse events, patients with endocrinopathies can continue their immune checkpoint therapy, provided the hormone replacement therapy is adequate and the symptoms are controlled. Though patients who have developed immune-related adverse events demonstrate superior antitumor activity and overall survival, due to the high morbidity associated with the immune-related adverse events, researchers are trying to uncouple the antitumour activity associated with immune checkpoint inhibitor therapy from the immune-related adverse events, to preserve antitumour activity without adverse events.

Organ-specific Adverse Events of Immune Checkpoint Inhibitor Therapy, with Special Reference to Endocrinopathies

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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.