Between 1990 and 1999, twenty-one infants were diagnosed with ALL in the Czech Republic and only 6 of them were treated according to a protocol designed specifically for the infants. Between 2000 and 2005 fourteen infants were diagnosed with ALL and 13 of them were treated in the international randomized study Interfant 99.
Five-years EFS of 482 patients enrolled in the international study Interfant 99 46% and overall survival 55% showing the improvement in comparison with majority of the previous studies.