Maternal, fetal, and neonatal imatinib levels with treatment of chronic myeloid leukemia in pregnancy

BACKGROUND: Pregnant women with chronic myeloid leukemia (CML) can be treated effectively with the tyrosine-kinase inhibitor imatinib, but data regarding fetal and neonatal exposure and safety are limited. CASE: We present a patient with newly diagnosed CML in early pregnancy. Leukapheresis and interferon-a were initiated in the second trimester with limited benefit. Imatinib was subsequently started at 28 weeks of gestation with complete hematologic response within 4 weeks. No significant maternal or neonatal adverse effects were noted, but imatinib and its primary active metabolite concentrated in maternal breast milk and neonatal urine. CONCLUSION: Imatinib is effective for CML in pregnancy, but caution is warranted in light of potentially unrecognized fetal and neonatal effects.