Antithymocyte globulin for aplastic anemia secondary to pembrolizumab: a case report and review of literature.

Aplastic anemia is a rare but potentially serious complication of immune checkpoint inhibitor therapy. The authors present a case of pembrolizumab-induced aplastic anemia that was refractory to steroids but had some hematologic response to modified-dosing antithymocyte globulin (ATG). This is the first reported case of hematological response to ATG for immune checkpoint inhibitor-induced aplastic anemia and the first reported case of modified ATG dosing for this indication. Cases of immune checkpoint inhibitor-induced aplastic anemia and management options are also summarized. Given the high morbidity and mortality associated with ICI-induced aplastic anemia, more data is necessary to guide evidence-based management recommendations. Immune checkpoint inhibitors (ICIs) are a form of anticancer therapy that enlists the body's own immune system to fight cancer cells. Although remarkably effective against some types of cancer, ICIs can also cause the augmented immune system to attack noncancer cells, resulting in unwanted off-target side effects. One rare but potentially serious complication of ICIs is aplastic anemia, where the body stops producing enough new blood cells. There is little known about ICI-induced aplastic anemia. The authors present a case of ICI-induced aplastic anemia that did not improve with standard treatment but had some response to antithymocyte globulin, which has not been previously reported. Previously published cases of ICI-induced aplastic anemia and management options are also summarized.