Table 1.

Details of treatment for the randomized regimens

Phase and drug	Dose	Schedule
Induction, 4 wk
IT cytarabine	Age-adjusted†	Day 0
Vincristine	1.5 mg/m2 (2 mg max)	Days 0, 7, 14, 21
Asparaginase‡	6000 U/m2	M, W, F × 9 doses
Prednisone	40 mg/m2/d	Days 0-27
IT MTX	Age-adjusted†	Days 7, 28
Consolidation, 4 wk
Vincristine	1.5 mg/m2 (2 mg max)	Day 0
Prednisone	Taper	Days 0-10
Mercaptopurine or	75 mg/m2/d	Days 1-27
Thioguanine§	50 or 60 mg/m2/d	Days 1-27
IT MTX or	Age-adjusted†	Days 7, 14, 21
ITT	Age-adjusted†	Days 7, 14, 21
IM no. 1, 8 wk
Vincristine	1.5 mg/m2 (2 mg max)	Days 0, 28
Prednisone	40 mg/m2/d	Days 0-4, 28-32
Mercaptopurine or	75 mg/m2/d	Days 0-49
Thioguanine§	50 or 60 mg/m2/d	Days 0-49
MTX	20 mg/m2/d	Weekly × 8 doses
DI no. 1, 8 wk
Vincristine	1.5 mg/m2 (2 mg max)	Days 0, 7, 14
Asparaginase‡	6000 U/m2	M, W, F × 6 doses
Dexamethasone	10 mg/m2/d	Days 0-6, 14-20
Doxorubicin	25 mg/m2/d	Days 0, 7, 14
Cytarabine	75 mg/m2/d	Days 28-31, 35-38
Cyclophosphamide	1000 mg/m2	Day 28
Thioguanine	60 mg/m2/d	Days 28-41
IT MTX or	Age-adjusted†	Days 0, 28, 35
ITT	Age-adjusted†	Days 0, 28, 35
IM no. 2, 8 wk
As in “IM no. 1”	—	—
DI no. 2, 8 wk
As in “DI no. 1”	—	—
Maintenance,*12-wk cycles
Vincristine	1.5 mg/m2 (2 mg max)	Days 0, 28, 56
Prednisone	40 mg/m2/d	Days 0-4, 28-32, 56-60
Mercaptopurine or	75 mg/m2/d	Daily
Thioguanine§	50 or 60 mg/m2/d	Daily
MTX (oral)	20 mg/m2/dose	Weekly
IT MTX or	Age-adjusted†	Day 0
ITT	Age-adjusted†	Day 0

^*Total duration of treatment for boys was 38 months; for girls, 26 months.

^†Intrathecal; see Table 2 for dosing.

^‡Asparaginase preparation: E coli (Elspar; Merck, Whitehouse Station, NJ); Erwinia asparaginase replaced Elspar following severe allergic reactions.

^§The 100% targeted dose of thioguanine was changed from 60 to 50 mg/m²/d in February 1998.