A case of successful treatment with eltrombopag for severe immune-related thrombocytopenia induced by atezolizumab:Case report.

Immune checkpoint inhibitors (ICIs) have shown impressive anti-tumor effects against multiple types of malignancies. Among the wide variety of immune-related adverse events (irAEs), immune-related thrombocytopenia (ITP) is relatively rare but often clinically significant and life-threatening. However, the appropriate treatment for severe ITP has not been determined. We herein report an 82-year-old male patient with non-small-cell lung cancer who developed severe ITP three weeks after starting the third course of atezolizumab. The initial combination therapy with high-dose prednisolone, intravenous immunoglobulin and platelet transfusion was ineffective. However, additional treatment with eltrombopag, a thrombopoietin receptor agonist, resulted in remarkable improvement in the thrombocytopenia. J. Med. Invest. 70 : 516-520, August, 2023.

Acquired amegakaryocytic thrombocytopenia after durvalumab administration.

Immune checkpoint inhibitors (ICIs), despite their ability to potentiate antitumor T-cell responses, may cause various immune-related adverse events. Most cases of thrombocytopenia induced by ICIs have revealed a pathophysiologic mechanism of immune thrombocytopenia with increased platelet destruction and preserved megakaryocytes. Acquired amegakaryocytic thrombocytopenic purpura (AATP) is an unusual disorder characterized by thrombocytopenia with markedly diminished bone marrow megakaryocytes in the presence of otherwise normal hematopoiesis. AATP caused by ICIs has not been reported on. Herein, we present the case of a 79-year-old man diagnosed with squamous cell carcinoma of the lung who developed AATP after two courses of durvalumab, a drug targeting programmed death-ligand 1. Two weeks after the second cycle, his platelet count decreased to 2.1 × 104/µL. After the patient underwent platelet transfusion, his platelet count increased to 8.1 × 104/µL the next day but subsequently decreased repeatedly even after the ICI was discontinued. Six weeks after the second cycle, he developed interstitial pneumonia and was administered prednisolone (50 mg/day). However, thrombocytopenia did not improve. Bone marrow biopsy showed scarce megakaryocytes (< 1 megakaryocyte/10 high-power fields) with preservation of myeloid and erythroid series. Myelodysplasia, myelofibrosis, or metastatic lesions were not observed. Cytogenetic analysis showed a normal male karyotype of 46XY. Hence, the patient received eltrombopag, a thrombopoietin receptor agonist, and his platelet count subsequently improved. After recovery, bone marrow aspiration revealed a normal number of megakaryocytes. AATP is rarely the type of thrombocytopenia induced by ICIs and may be successfully treated with thrombopoietin receptor agonists.

Eltrombopag olamine for refractory immune-related thrombocytopenia induced by pembrolizumab in a non-small cell lung cancer patient.

OBJECTIVES: Immune checkpoint inhibitors (ICIs) have shown antitumor activity against a wide variety of malignancies. ICI-induced immune-related thrombocytopenia is a rare immune-related adverse event (irAE). Little is known about the treatment of refractory immune-related thrombocytopenia in non-small cell lung cancer (NSCLC) patients treated with pembrolizumab. RESULTS: We report the case of a patient with advanced NSCLC complicated by pembrolizumab-induced refractory immune-related thrombocytopenia who showed remarkable improvement in the thrombocytopenia in response to eltrombopag olamine treatment. CONCLUSION: Eltrombopag olamine can be a viable treatment option for refractory pembrolizumab-induced immune-related thrombocytopenia in an NSCLC patient.

Nivolumab-related severe thrombocytopenia in a patient with relapsed lung adenocarcinoma: a case report and review of the literature.

BACKGROUND: Immune checkpoint inhibitor therapy has changed the standard drug therapy for relapsed or advanced non-small cell lung cancer; its efficacy is well-recognized by pulmonary physicians, oncologists, and thoracic surgeons. Nivolumab, one of the anti-programmed cell death 1 antibodies, was the first immune checkpoint inhibitor to be approved and is used as a standard second-line regimen for patients with non-small cell lung cancer irrespective of the expression of programmed cell death ligand 1. Programmed cell death 1 antibodies have been generally confirmed to be less toxic than conventional cytotoxic chemotherapy, although unusual immune-related adverse events such as type I diabetes mellitus, adrenal failure, and myasthenia gravis may occur with a very low incidence. A case of severe grade V immune-related thrombocytopenia after two courses of nivolumab as second-line therapy for relapsed non-small cell lung cancer is reported. CASE PRESENTATION: An 82-year-old Japanese woman with relapsed lung adenocarcinoma was treated with nivolumab as second-line systemic therapy at our institute. Her laboratory data indicated thrombocytopenia suspected to be an immune-related adverse event following two courses of nivolumab. Subsequently, she developed a massive pulmonary hemorrhage and left cerebral infarction despite intensive treatment including systemic steroid therapy. Although there have been a few reports of thrombocytopenia caused by nivolumab, this is the first report of grade V thrombocytopenia following administration of nivolumab for relapsed non-small cell lung cancer. CONCLUSION: A very difficult case of grade V immune-related thrombocytopenia after the administration of nivolumab as second-line therapy for relapsed lung adenocarcinoma was described. Immune-related thrombocytopenia is a rare adverse event, but it must be considered a possible complication because it may become critical once it has occurred.

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

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