Chronic Myeloid Leukemia and Pregnancy: When Dreams Meet Reality. State of the Art, Management and Outcome of 41 Cases, Nilotinib Placental Transfer

The overwhelming success of tyrosine kinase inhibitor (TKI) therapy in chronic myeloid leukemia (CML) patients has opened a discussion among medical practitioners and the lay public on the real possibility of pregnancy and conception in females and males with CML. In the past 10 years this subject has acquired growing interest in the scientific community and specific knowledge has been obtained "from bench to bedside". Embryological, pharmacological, and pathophysiological studies have merged with worldwide patient databases to provide a roadmap to a successful pregnancy and birth in CML patients. Male conception does not seem to be affected by TKI therapy, since this class of drugs is neither genotoxic nor mutagenic, however, caution should be used specially with newer drugs for which little or no data are available. In contrast, female patients should avoid TKI therapy specifically during the embryonic stage of organogenesis (5-12 weeks) because TKIs can be teratogenic. In the last 15 years, 41 pregnancies have been followed in our center. A total of 11 male conceptions and 30 female pregnancies are described. TKI treatment was generally terminated as soon as the pregnancy was discovered (3-5 weeks), to avoid exposure during embryonic period and to reduce the risk of needing treatment in the first trimester. Eleven pregnancies were treated with interferon, imatinib or nilotinib during gestation. Nilotinib plasma levels in cord blood and maternal blood at delivery were studied in 2 patients and reduced or absent placental crossing of nilotinib was observed. All of the patients were managed by a multidisciplinary team of physicians with obligatory hematological and obgyn consultations. This work provides an update on the state of the art and detailed description of pregnancy management and outcomes in CML patients.