Pharmacogenetics Of Cyp3a5 And Effects Of Corticosteroids In Children Treated For Acute Lymphoblastic Leukemia.

The treatment of children with acute lymphoblastic leukaemias (ALL) according to EORTC 58951 protocol is divided into 3 phases (induction, consolidation, maintenance). During the induction phase, patients are randomly assigned to receive either prednisone or dexamethasone (associated with anticancer drugs). The response to corticotherapy is evaluated by the quantification of the residual disease (RD) at day 35 of treatment and has an major impact on prognosis and treatment: patients with an RD lower than 10−2/100 000 cells. The distribution of CYP3A genotypes was : *1/*1: 2,7%, *1/*3: 18,8% and *3/*3: 78,5%, in aggrement with already published data. CYP3A5*2 and *6 mutations were not found There was no difference in the response to corticosteroid treatment according to individual CYP3A5 genotypes or to the type of corticosteroid. Our results did not evidence an impact of CYP3A5 on the initial response to corticosteroids. Clinical Pharmacology & Therapeutics (2004) 75, P20–P20; doi: 10.1016/j.clpt.2003.11.075