Acquired Hemophilia A Secondary to an Immune Checkpoint Inhibitor: A Case Report

James Fletcher; Robert Bird; Andrew J W McLean; Kenneth O'Byrne; Wen Xu

doi:10.1016/j.jtocrr.2022.100409

Acquired Hemophilia A Secondary to an Immune Checkpoint Inhibitor: A Case Report

JTO Clin Res Rep. 2022 Sep 19;3(11):100409. doi: 10.1016/j.jtocrr.2022.100409. eCollection 2022 Nov.

Authors

James Fletcher^{1

2}, Robert Bird¹, Andrew J W McLean¹, Kenneth O'Byrne^{1

3}, Wen Xu^{1

2}

Affiliations

¹ Division of Cancer Services, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
² Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
³ Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia.

Abstract

We report a case of a patient with extensive-stage SCLC who developed acquired hemophilia A during maintenance atezolizumab therapy. The patient initially presented with asymptomatic anemia, a prolonged acquired prothrombin time, and factor VIII (FVIII) deficiency. Acquired FVIII autoantibodies were detected, confirming the diagnosis of acquired hemophilia. Atezolizumab was ceased and high-dose prednisolone was initiated. He subsequently developed an extensive spontaneous upper limb subcutaneous hematoma and shoulder hemarthrosis despite improving FVIII inhibitor titers on prednisolone. His acute bleeding was successfully treated with recombinant factor VII, and rituximab was added to prednisolone. Given the quiescent malignancy, 16 months of preceding treatment with atezolizumab, and improvement with immunosuppression, a diagnosis of immune checkpoint inhibitor-induced hemophilia A was made. Severe hematologic immune-related adverse events such as this case of acquired hemophilia have rarely been reported in the literature.

Keywords: Case report; Factor VIII; Hemophilia; Immune-related adverse events; Immunotherapy.

Publication types

Case Reports