Twin pregnancy during treatment with asciminib for chronic myeloid leukemia – a case report

Managing chronic myeloid leukemia during pregnancy presents significant challenges, with limited treatment options available depending on the stage of pregnancy. All existing tyrosine kinase inhibitors are considered teratogenic, especially during the first trimester and should be avoided. In this case report, we detail the successful, unplanned dichorionic diamniotic twin pregnancy of a patient with chronic-phase myeloid leukemia previously resistant to imatinib and dasatinib who was exposed to the allosteric tyrosine kinase inhibitor asciminib during the early weeks of gestation. Upon confirmation of the pregnancy, asciminib was discontinued, and the patient was treated with pegylated interferon. The patient developed preeclampsia, and the twins were delivered prematurely via cesarean section. No other abnormalities were observed in the newborns. During her pregnancy, the patient experienced a loss of the major molecular response; however, she regained it within two months of resuming asciminib after giving birth. To our knowledge, this case represents the first report of a twin pregnancy during asciminib treatment.