New drug shows promise for aggressive leukemia but carries serious clot risk

This study tested the drug ponatinib in 51 adults with a fast-growing form of chronic myeloid leukemia (CML) who had little or no prior treatment. The goal was to see if ponatinib could control the disease by blocking a protein that drives leukemia growth. However, the drug can cause dangerous blood clots in about 1 in 4 patients, which may lead to heart attack, stroke, or death. The study was stopped early, but results help doctors understand the benefits and risks of using ponatinib as an initial therapy.