Dasatinib - CAS 302962-49-8

On January 2008, dasatinib (70 mg twice daily) was started. The patient tolerated treatment well with no significant side effects. He was being followed up regularly with blood studies. By the end of February 2009 he informed us that his wife had a successful delivery of a healthy baby boy after a full term pregnancy. The baby was 3.1 kg and 46 cm with no congenital anomalies. At the time of conception, the patient was receiving dasatinib 140 mg/day, and the cumulative dose of dasatinib was approximated 350 g. At the time of writing this report, the patient was doing well on dasatinib. His last evaluation showed that he was in complete hematological response with no molecular response (quantitative analysis of peripheral blood BCR-ABL mRNA levels using real-time polymerase chain reaction were 6.00E-2, relative expression ratio of bcr-abl to G6PDH (ROCHE Diagnostics, Light Cycler 2.0). His baby was 7 months old, and he was in good health.

Takahashi et al. recently reported in this journal that administration of an acid suppressant such as an H2-receptor antagonist (H2RA) and a proton pump inhibitor can decrease the absorption of dasatinib from the gastrointestinal tract, thereby resulting in a significant decrease in plasma dasatinib concentration. Here, we report a patient treated with dasatinib and H2RA famotidine whose plasma dasatinib concentration increased dramatically after the cessation of famotidine.