Clinical characteristics, treatment, and outcomes of nivolumab induced immune thrombocytopenia

Immune thrombocytopenia (ITP) represents an uncommon hematological side effect associated with nivolumab, and its distinct clinical attributes remain poorly defined. This research aimed to explore the clinical manifestations and outcomes of ITP induced by nivolumab. Reports on nivolumab induced ITP up to April 30, 2024, were collected for retrospective analysis. The study involved 34 patients with a median age of 67 years (range 32, 82). The onset of ITP varied from 10 to 100 days post initial dosage, with a median onset at 70 days. The majority of patients exhibited no symptoms, with only 23.5% experiencing clinically significant bleeding and 11.8% facing non-clinically significant bleeding. The median platelet count was 12 × 10⁹/L (range 0, 115), with 67.6% of patients having platelet levels below 25 × 10⁹/L. Bone marrow biopsy revealed mainly elevated megakaryocytes. Platelet-associated IgG levels were elevated with a median of 210 ng/10⁷ cells (range 73, 1130). Subsequent interventions, which included cessation of nivolumab, administration of systemic corticosteroids, intravenous immunoglobulin therapy, a thrombopoietin receptor agonist, platelet transfusion, and rituximab treatment, resulted in 82.4% of subjects achieving normalized platelet counts, whereas 5.9% passed away due to ITP. ITP is a rare life-threatening immune-related adverse event and necessitates close monitoring. Systemic steroids are the primary treatment for ITP, while intravenous immunoglobulin, thrombopoietin receptor agonist and rituximab are other options.