Outcome for infants on CCG-107 and CCG- 1883 improved, compared with historical controls. Marrow relapse remains the primary mode of failure. Isolated CNS relapse rates are low, indicating that intrathecal chemotherapy combined with very-high-dose systemic therapy provides adequate protection of the CNS. The overall unsatisfactory outcome observed for the infant ALL population warrants the future use of novel alternative therapies.

Delint improves the EFS rate of children with ALL and intermediate presenting features. Maintenance IT MTX can be safely substituted for CXRT for presymptomatic CNS therapy in children with intermediate-risk characteristics less than 10 years of age.

IT MTX during induction, consolidation, and maintenance provides protection from CNS relapse in patients with intermediate-risk ALL equivalent to that provided by CXRT if more intensive systemic therapy is given. The CNS relapse rate with either CXRT or IT MTX is in part dependent on the associated systemic therapy. For intermediate-risk patients less than 10 years of age, IT MTX with an intensified systemic regimen provided CNS prophylaxis comparable to that provided by CXRT, whereas older patients had fewer systemic relapses if they received CXRT.