Cardiovascular toxicity from tyrosine kinase inhibitors in chronic myeloid leukemia with severe dilated cardiomyopathy.

Tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of patients with chronic myeloid leukemia (CML). However, few patients maintain remission after discontinuing TKIs, and most require long-term treatment. Prolonged use of TKIs is associated with an increased risk of cardiovascular events (CVEs), particularly in patients with pre-existing cardiovascular comorbidities. We present the case of a 37-year-old man with a decade-long history of severe dilated cardiomyopathy that responded inadequately to standard pharmacologic management, who was under consideration for heart transplantation. Following a diagnosis of CML, the patient experienced various CVEs with TKIs, including dasatinib, bosutinib, imatinib, and nilotinib. These agents were discontinued, and treatment was switched to asciminib, a novel agent that targets the myristoyl pocket of the BCR::ABL1 protein distinct from the ATP-binding site targeted by conventional TKIs. This treatment was well tolerated without any CVEs. Given its minimal off-target activity and lower reported incidence of CVEs, asciminib may offer a viable and safer therapeutic option for CML patients with advanced cardiovascular comorbidities, including those awaiting heart transplantation.