First Reported Use of Immune Checkpoint Inhibitor for Treatment of Cancer in a Patient with Acquired Hemophilia A

Acquired hemophilia A is a rare but serious bleeding disorder that occurs because of neutralizing autoantibodies, also called inhibitors that target coagulation factor VIII (FVIII). Although it is a rare disorder, it has high morbidity and mortality with serious, sometimes life-threatening bleeding, often occurring. Immunotherapy with immune checkpoint inhibitors (ICI) is now a key pillar in treatment of malignancies. They have improved outcomes in malignancy but given their mechanism of action, which stimulates the immune response, autoimmune-associated adverse effects are a concern. Several case reports have identified a risk of AHA occurrence in patients treated with ICI. There are no case reports documenting the use or outcomes of ICI in patients with pre-existing AHA. Here we present the first ever case of a patient with AHA in complete remission treated successfully with ICI for lung cancer without relapse in AHA.