Delayed immune thrombocytopenia after discontinuation of nivolumab therapy: A case report and literature review

PD-1/PD-L1 inhibitor-induced immune thrombocytopenia: A pharmacovigilance study and systematic review

INTRODUCTION

Programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) immune checkpoint inhibitors (ICIs) are used for a variety of cancers and are associated with a risk of developing immune-related adverse events, most commonly dermatitis, colitis, hepatitis, and pneumonitis. Immune-mediated hematologic toxicities have been reported, but are less well-described in the literature. Immune thrombocytopenia (ITP) is a rare autoimmune, hematologic adverse event that has been reported with PD-1/PD-L1 inhibitors.

METHODS

We performed a retrospective observational analysis of the United States Food and Drug Administration Adverse Event Reporting System (FAERS) data. We searched for cases of ITP reported with exposure to PD-1/PD-L1 inhibitors from initial FDA approval for each agent to September 30, 2022. Disproportionality signal analysis was done by calculating the reporting odds ratio (ROR). Oxaliplatin was used as a positive control for sensitivity analysis as it is an anticancer therapy that has been associated with drug-induced ITP. A systematic review of the PubMed database was also conducted to identify published cases of PD-1/PD-L1 inhibitor-induced ITP.

RESULTS

There were 329 reports of ITP with ICIs in the FAERS database that were reviewed for a disproportionality signal, including atezolizumab (n = 27), durvalumab (n = 17), nivolumab (n = 160), and pembrolizumab (n = 125). The ROR was significant for atezolizumab (ROR 5.39, 95 % CI 3.69-7.87), avelumab (ROR 10.32, 95 % CI 4.91-21.69), durvalumab (ROR 7.91, 95 % CI 4.91-12.75), nivolumab (ROR 9.76, 95 % CI 8.34-11.43), and pembrolizumab (ROR 12.6, 95 % CI 10.55-15.06). In our systematic review, we summated 57 cases of ICI-induced ITP. Nivolumab and pembrolizumab had the most reported cases of ITP in the literature. Most cases reported (53 %) included ITP-directed therapies beyond corticosteroids for the management of ICI-induced ITP.

CONCLUSION

There is a significant reporting signal of ITP with several ICI agents. Clinicians should be aware of and monitor for signs of this potentially serious adverse event.

Efficacy and Immunomodulating Properties of Eltrombopag in Aplastic Anemia following Autologous Stem Cell Transplant: Case Report and Review of the Literature

Thrombopoietin receptor agonists (TPO-RA) are currently indicated for the treatment of chronic immune thrombocytopenia and relapsed refractory aplastic anemia. However, the off-label use of these drugs is more and more frequent, including in the setting of aplasia secondary to chemotherapy and hemopoietic stem cell transplant (SCT). Growing evidence suggests that mechanisms of action of TPO-RA go beyond the TPO-receptor stimulation and point at the immunomodulating properties of these drugs. Here, we present a case of prolonged bone marrow aplasia secondary to autologous SCT treated with eltrombopag. We describe the clinical efficacy and the immunomodulating effect of this drug on inflammatory cytokine profile and bone marrow histology. Furthermore, we provide a review of the most recent literature highlighting the efficacy and safety of TPO-RA after SCT and chemotherapy for hematologic conditions.

Immune Thrombocytopenia Induced by Immune Checkpoint Inhibitrs in Lung Cancer: Case Report and Literature Review

Immune checkpoint inhibitors (ICIs), including antibodies targeting programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1), are being extensively used on advanced human malignancies therapy. The treatment with ICIs have acquired durable tumor inhibition and changed the treatment landscape in lung cancer. Immune-related adverse events including pneumonitis and thyroiditis have been well described, but less frequent events, such as ICIs-induced thrombocytopenia, are now emerging and may sometimes be severe or fatal. Since early detection and prompt intervention are crucial to prevent fatal consequences, it is of outmost importance that medical staff is aware of these potential toxicities and learn to recognize and treat them adequately. This review focuses on the epidemiology, clinical presentation, mechanisms, and clinical management of ICIs-induced thrombocytopenia in patients with lung cancer. We also present a patient with advanced lung adenocarcinoma who received the PD-L1 inhibitor atezolizumab and eventually developed severe thrombocytopenia. The case indirectly suggests that cytokine changes might contribute to immune dysregulation in ICIs-induced thrombocytopenia.