Unexpected serious aplastic anemia from PD-1 inhibitors: beyond what we know

When inflammatory stressors dramatically change, disease phenotypes may transform between autoimmune hematopoietic failure and myeloid neoplasms

Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome are paradigms of autoimmune hematopoietic failure (AHF). Myelodysplastic syndrome and acute myeloid leukemia are unequivocal myeloid neoplasms (MNs). Currently, AA is also known to be a clonal hematological disease. Genetic aberrations typically observed in MNs are detected in approximately one-third of AA patients. In AA patients harboring MN-related genetic aberrations, a poor response to immunosuppressive therapy (IST) and an increased risk of transformation to MNs occurring either naturally or after IST are predicted. Approximately 10%-15% of patients with severe AA transform the disease phenotype to MNs following IST, and in some patients, leukemic transformation emerges during or shortly after IST. Phenotypic transformations between AHF and MNs can occur reciprocally. A fraction of advanced MN patients experience an aplastic crisis during which leukemic blasts are repressed. The switch that shapes the disease phenotype is a change in the strength of extramedullary inflammation. Both AHF and MNs have an immune-active bone marrow (BM) environment (BME). In AHF patients, an inflamed BME can be evoked by infiltrated immune cells targeting neoplastic molecules, which contributes to the BM-specific autoimmune impairment. Autoimmune responses in AHF may represent an antileukemic mechanism, and inflammatory stressors strengthen antileukemic immunity, at least in a significant proportion of patients who have MN-related genetic aberrations. During active inflammatory episodes, normal and leukemic hematopoieses are suppressed, which leads to the occurrence of aplastic cytopenia and leukemic cell regression. The successful treatment of underlying infections mitigates inflammatory stress-related antileukemic activities and promotes the penetration of leukemic hematopoiesis. The effect of IST is similar to that of treating underlying infections. Investigating inflammatory stress-powered antileukemic immunity is highly important in theoretical studies and clinical practice, especially given the wide application of immune-activating agents and immune checkpoint inhibitors in the treatment of hematological neoplasms.

Antithymocyte globulin for aplastic anemia secondary to pembrolizumab: a case report and review of literature

Aplastic anemia is a rare but potentially serious complication of immune checkpoint inhibitor therapy. The authors present a case of pembrolizumab-induced aplastic anemia that was refractory to steroids but had some hematologic response to modified-dosing antithymocyte globulin (ATG). This is the first reported case of hematological response to ATG for immune checkpoint inhibitor-induced aplastic anemia and the first reported case of modified ATG dosing for this indication. Cases of immune checkpoint inhibitor-induced aplastic anemia and management options are also summarized. Given the high morbidity and mortality associated with ICI-induced aplastic anemia, more data is necessary to guide evidence-based management recommendations.

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.

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.

What could be a cancer mission objective if we join our forces in the fight against cancer?

The European cancer burden is growing rapidly, with an estimated 2 million deaths a year according to the latest research. As almost half of cancers are diagnosed after the age of 65, and considering the aging European population, a tidal wave of cancer cases will sweep across Europe within the coming decades. Without major action, the additional number of annual cancer cases is expected to rise from 4.2 million to 5.2 million by 2040. If we are to reach plateauing numbers by 2040 (as a minimum goal), this would require 0.75% annual reduction in risk and 1% reduction in risk of death. These challenges call for attack from various angles, coordinated efforts, rational strategies, initiatives throughout the cancer trajectory, activities to reduce inequities, and implementation of evidence-based measures. In order to defeat the societal challenges of cancer through innovation, Europe will need to join forces and connect the European Commission and the member states, politicians and citizens, industries and patient associations. A cancer mission should thus unite the public and patient viewpoint to the perspective of cancer professionals. The authors describe a plan that has been agreed upon among some of the major European Cancer organizations and associations. This plan uses a cancer mission as a tool and must deliver robust medical evidence to patients and doctors through high-quality research delivering sustainable and affordable strategies for prevention, treatment, and follow-up.