Can Treatment with Venetoclax for Chronic Lymphocytic Leukemia (CLL) Result In Autoimmune Hemolytic Anemia?

BACKGROUND: Chronic lymphocytic leukemia (CLL) is a hematological disease characterized by the clonal proliferation and accumulation of neoplastic B lymphocytes in the blood, bone marrow, lymph nodes, and spleen. Autoimmune hemolytic anemia (AIHA) is an acquired hemolytic anemia in which the destruction of erythrocytes is helped by anti-erythrocyte auto-antibodies. This has a controversial effect on the clinical outcome and survival of patients with CLL. Venetoclax, a second-generation BH3 mimetic compound, is one of the new therapies that has been approved for the treatment of CLL. Venetoclax disrupts the antiapoptotic signaling through BCL2. Common adverse events associated with venetoclax include neutropenia, thrombocytopenia, and diarrhea. This case report describes a patient with CLL who developed AIHA when treated with venetoclax.
CASE REPORT: A patient of 62-year-old woman, who was treated with multiple lines of therapy, presented autoimmune hemolytic anemia after treatment with venetoclax. The anemia was resolved after holding venetoclax and being treated with rituximab. In January 2019, there were reports of 7 patients developing AIHA related to venetoclax therapy in Europe, according to the EudraVigilance database. How venetoclax can cause AIHA is not completely clear. This complication can happen when the erythrocyte antigen is altered by the drug that can produce antibodies. The other described mechanism is the binding of the drug with erythrocytes, which leads to production of an immune response.
CONCLUSIONS: Although AIHA can be a complication of CLL, it may be caused by treatment with venetoclax. That may be confirmed after eliminating other causes.

Keywords: Anemia, Hemolytic, Autoimmune, Drug-Related Side Effects and Adverse Reactions, Leukemia, Lymphocytic, Chronic, B-Cell