Trial Information

Treatment of Late Isolated Extramedullary Relapse From Acute Lymphoblastic Leukemia (ALL) (Initial CR1≥ 18 Months)

OBJECTIVES:

Primary

- Determine the efficacy of intensified systemic chemotherapy with reduced-dose CNS
radiotherapy in patients with acute lymphoblastic leukemia and late isolated CNS
relapse.

- Determine the efficacy of intensive systemic chemotherapy without testicular
radiotherapy in patients with acute lymphoblastic leukemia and late isolated testicular
relapse.

- Determine the toxicity of these regimens in these patients.

Secondary

- Determine whether bone marrow involvement is present at the time of extramedullary
relapse in patients treated with these regimens.

- Correlate pretreatment minimal residual disease with outcomes in patients treated with
these regimens.

- Correlate the role of host gene polymorphisms with toxicity of these regimens and
incidence and outcome in these patients.

- Determine the neuropsychological sequalae associated with isolated CNS relapse and
these treatment regimens in these patients.

OUTLINE: This is a pilot, multicenter study. All patients receive common induction,
consolidation, re-induction, and intensification chemotherapy. Patients are stratified to
maintenance therapy according to site of extramedullary relapse (CNS vs testicular).

- Induction therapy (weeks 1-4): Patients receive vincristine IV on days 1, 8, 15, and
22; oral dexamethasone twice daily on days 1-28; daunorubicin* IV over 15 minutes on
days 1, 8, and 15; and intrathecal triple therapy** (ITT) comprising methotrexate,
hydrocortisone, and cytarabine on days 1, 8, 15, and 22.

NOTE: *The total dose of anthracyclines on this study is capped at 450 mg/m2. Once this dose
is reached, all subsequent doses of daunorubicin are omitted.

NOTE: **Patients with isolated testicular relapse receive ITT on day 1 only.

In addition to the above, patients with isolated testicular relapse also receive high-dose
methotrexate IV continuously over 24 hours on day -14. Patients with clinical signs of
disease at the end of induction undergo testicular biopsy.

Patients with CNS disease who do not achieve CNS remission after induction therapy receive
additional ITT as above on days 29 and 36.

- Consolidation therapy (weeks 5-10): Patients receive high-dose cytarabine IV over 3
hours twice daily on days 1-2 and 22-23 and pegaspargase intramuscularly (IM) on days 2
and 23. Patients also receive filgrastim (G-CSF) subcutaneously (SC) beginning on days
3 and 24 and continuing until blood counts recover.

Patients with isolated testicular relapse with positive biopsy results at the end of
induction undergo testicular radiotherapy once daily for a total of 12 fractions during
consolidation therapy.

- Intensification I (weeks 11-22): Patients receive high-dose methotrexate with
leucovorin calcium rescue IV over 24 hours on days 1, 22, 43, and 64 and oral
mercaptopurine once daily on days 2-6, 23-27, 44-48, and 65-69. Patients also receive
etoposide IV over 1 hour and cyclophosphomide IV over 15-30 minutes on days 8, 29, 50,
and 71. Patients receive ITT* on days 15, 36, 57, and 78.

NOTE: *Patients with isolated testicular relapse receive ITT on days 36 and 78 only.

- Reinduction therapy (weeks 23-26): Patients receive vincristine IV on days 1, 8, 15,
and 22; oral dexamethasone twice daily on days 1-7 and 15-21, and daunorubicin IV over
15 minutes on days 1, 8, and 15.

- Intensification II (weeks 27-50): Patients receive high-dose cytarabine IV over 3 hours
twice daily on days 1-2, 43-44, 85-86, and 127-128; pegaspargase IM on days 2, 44, 86,
and 128; ITT* on days 22, 64, 106, and 148; high-dose methotrexate IV continuously over
24 hours on days 29, 71, 113, and 155; oral mercaptopurine on days 30-34, 72-76,
114-118, and 156-160; and etoposide IV over 1 hour and cyclophosphamide IV over 15-30
minutes on days 36, 78, 120, and 162. Patients also receive G-CSF SC beginning on days
3, 45, 87, and 129 and continuing until blood counts recover.

NOTE: *Patients with isolated testicular relapse receive ITT on days 22 and 106 only.

- Chemotherapy and radiotherapy (weeks 51-54): Patients receive oral dexamethasone twice
daily on days 1-7 and 15-21, vincristine IV on days 1, 8, and 15, and pegaspargase IM
on days 1 and 15.

Patients with isolated CNS relapse also undergo cranial radiotherapy once daily, 5 days a
week, for a total of 12 fractions.

- Maintenance therapy for isolated CNS relapse: (weeks 55-104): Patients receive
dexamethasone PO orIV twice daily on days 1-5; oral mercaptopurine once daily on days
1-42; methotrexate IM on days 1, 8, 15, 22, 29, and 36; and vincristine IV and
cyclophosphomide IV over 1 hour on days 43, 50, 57, and 64. Treatment repeats every 10
weeks for 5 courses.

- Maintenance therapy for isolated testicular relapse:

- (Weeks 55-74): Patients receive ITT on day 1 and dexamethasone, mercaptopurine,
methotrexate, vincristine, and cyclophosphomide as in maintenance therapy for
isolated CNS relapse. Treatment repeats every 10 weeks for 2 courses.

- (Weeks 75-106): Patients receive vincristine IV on day 1; dexamethasone orally or
IV on days 1-5; oral mercaptopurine on days 1-28; and methotrexate IM on days 1,
8, 15, and 22. Treatment repeats every 28 days for 8 courses. Patients also
receive ITT on day 1 every 12 weeks for 3 doses.

Patients with combined testicular and CNS relapse receive high-dose methotrexate IV
continuously over 24 hours on day -14 in addition to the same chemotherapy and radiotherapy
administered during the induction, consolidation, intensification I, reinduction,
intensification II, and maintenance phases of therapy as isolated CNS relapse patients.

All patients undergo neuropsychological assessment within 3 months after completion of
induction therapy (before cranial radiotherapy) and at 2 years after completion of
treatment.

Patients are followed for survival.

PROJECTED ACCRUAL: A total of 257 patients (143 with isolated CNS relapse and 114 with
isolated testicular relapse) will be accrued for this study within 5.7 years.