Conventional compared with individualized chemotherapy for childhood XXXX .

@entity1 @entity981 @entity1619 @entity2663 @entity2592 @entity8624 @entity1499
BACKGROUND: The rate of clearance of antileukemic agents differs by a factor of 3 to 10 among @entity1 with @entity981 . We hypothesized that the outcome of treatment would be improved if doses were individualized to prevent low systemic exposure to the drugs in @entity1 with fast drug clearance. METHODS: We stratified and randomly assigned 182 @entity1 with newly diagnosed @entity981 to postremission regimens that included high-dose @entity1499 and @entity2663 plus @entity2592 . The doses of these drugs were based on body-surface area (in the conventional-therapy group) or the rates of clearance of the three medications in each @entity1 (in the individualized-treatment group). In the individualized-treatment group, doses were increased in @entity1 with rapid clearance and decreased in @entity1 with very slow clearance. RESULTS: @entity1 who received individualized doses had significantly fewer courses of treatment with systemic exposures below the target range than did @entity1 who received conventional doses (P<0.001 for each medication). Among the @entity1 with @entity8624 , those who received individualized therapy had a significantly better outcome than those given conventional therapy (P=0.02); the mean (+/-SE) rates of continuous complete remission at five years were 76+/-6 percent and 66+/-7 percent, respectively. There was no significant difference between treatments for @entity1 with @entity1619 (P=0.54). In a proportional-hazards model, the time-dependent systemic exposure to @entity1499 , but not to @entity2663 or @entity2592 , was significantly related to the risk of early relapse in @entity1 with @entity8624 . CONCLUSIONS: Adjusting the dose of @entity1499 to account for the @entity1 's ability to clear the drug can improve the outcome in @entity1 with B-lineage @entity981 .
