Treatment of Acute Lymphoblastic Leukemia in Children

RISK CLASSIFICATION:

Patients received were classified into initial risk groups defined as:

High Risk (HR) High risk patients had any of the following features: age 10 years and older,
a white blood cell count of 50 000 cells per μL or higher, initial spinal fluid sample with
the presence of lymphoblasts and five or more white blood cells per high power field [Central
Nervous System (CNS)-3], or a T-cell phenotype.

Standard Risk (SR) All other patients were classified as standard risk.

Patients who achieved complete remission (CR) after 32 days of induction therapy defined as a
marrow specimen with less than 5% marrow blasts and evidence of normal haemopoiesis, absence
of extramedullary disease, and recovery of peripheral blood counts were randomly assigned in
a 1:1 ratio to receive IV-PEG or IM-EC. Randomization was stratified by final risk group
assigned based on end-induction minimal residual disease and cytogenetics as follows:

Very High Risk (VHR)

Any initial risk group and any of the following:

- MLL gene rearrangement

- Hypodiploidy (<45 chromosomes)

- B cell-ALL (high) end-induction minimal residual disease (MRD) (>/= 0.001)

High Risk (HR)

No VHR features, plus:

HR initial risk group OR

SR initial risk group with either of the following:

- CNS-2 or CNS-3 on day 18

- CNS-2 on day 32 OR

- t(9;22) Philadelphia chromosome positive (Ph+ ALL)

Standard Risk (SR)

No VHR features, plus:

SR initial risk group AND

* CNS-1 on day 18 and 32

NOTE: CNS-1, Cerebral spinal fluid (CSF) without blasts; CNS-2, CSF with blasts and < 5 WBC
per high-power field (HPF); CNS-3, CSF with blasts and ≥ 5 WBC per HPF

THERAPY:

INDUCTION

- Steroid prophase: Patients receive intrathecal (IT) cytarabine on day 1 and
methylprednisolone IV every 8 hours on days 1-3. Patients then proceed to remission
induction therapy.

Patients with CNS leukemia (CNS-2, CNS-3, or traumatic lumbar puncture [LP] with blasts) on
initial LP receive additional IT cytarabine twice weekly beginning on days 4-6 and continuing
until cerebrospinal fluid (CSF) is clear, followed by 2 additional doses. Patients with
cranial nerve palsy but no leukemia blasts in CSF or leukemic eye infiltrates also receive
additional IT cytarabine as above.

NOTE: Patients who received steroids within the past 7 days do not receive steroid prophase
treatment; instead they proceed directly to remission induction therapy according to their
risk group.

- Remission induction therapy (SR patients): Patients receive oral prednisone or
prednisolone 2-3 times daily OR methylprednisolone IV every 8 hours on days 4-32;
vincristine IV on days 4, 11, 18, and 25; doxorubicin hydrochloride (DOX) IV over 15
minutes on days 4 and 5; methotrexate (MTX) IV on day 6; pegasparaginase IV over 1 hour
on day 7; triple intrathecal therapy (TIT) comprising methotrexate, cytarabine, and
hydrocortisone on day 18; and IT MTX on day 32.

- Remission induction therapy (HR and VHR patients): Patients receive
prednisone/prednisolone OR methylprednisolone; vincristine; DOX; MTX IV;
pegasparaginase; TIT; and IT MTX as in the SR group. Patients also receive dexrazoxane
hydrochloride IV over 15 minutes preceding the DOX infusions on days 4 and 5.

NOTE: Patients who do not receive steroid prophase treatment also receive IT cytarabine on
day 4.

NOTE: Patients who are in CR on day 32 proceed to consolidation I. Patients who do not meet
protocol definition of CR on day 32 but have no evidence of persistent disease receive
vincristine IV weekly until CR is achieved. Patients with persistent marrow disease (greater
than 5% leukemic blasts) and/or persistent extramedullary disease or those who do not achieve
CR by day 53 are removed from the study.

NOTE: Patients with Ph+ ALL received imatinib (340 mg/m2 PO maximum 600 mg daily starting day
18) in combination with HR chemotherapy until they proceeded to stem cell transplant.
Patients with Ph+ ALL patients did not participate in asparaginase randomization but were
directly assigned to receive IM-EC during post-induction therapy.

CONSOLIDATION I

- Consolidation I (SR patients): Patients receive vincristine IV and IT MTX on day 1 and
oral mercaptopurine once daily on days 1-14. Patients also receive high-dose MTX (HDM)
IV continuously over 24 hours on day 1 and leucovorin calcium IV every 6 hours beginning
36 hours after the start of the HDM infusion and continuing until MTX levels are
undetectable. Patients proceed to CNS therapy after day 21.

- Consolidation I (HR patients): Patients receive vincristine, IT MTX, and mercaptopurine
as in the SR group. Patients also receive dexrazoxane hydrochloride IV over 15 minutes
followed by DOX IV over 15 minutes on day 1 and HDM with leucovorin calcium support as
in the SR group beginning 8-24 hours after the completion of the DOX infusion. Patients
proceed to CNS therapy after day 21.

- Consolidation I (VHR patients): Patients receive consolidation therapy in 3 stages.

- IA: Patients receive vincristine, IT MTX, and mercaptopurine as in the SR group.
Patients also receive dexrazoxane hydrochloride, DOX, HDM, and leucovorin calcium
as in the HR group.

- IB: Patients receive cyclophosphamide IV over 1 hour and IT MTX on day 22; oral
mercaptopurine once daily on days 22-35; and cytarabine IV on days 23-26 and 30-33.

- IC: Patients receive high-dose cytarabine IV over 3 hours every 12 hours on days 43
and 44; etoposide IV over 1 hour on days 45-47; and oral dexamethasone twice daily
on days 43-47. Patients also receive IM-EC weekly beginning on day 48 and
continuing for up to 30 weeks OR IV-PEG over 1 hour every 2 weeks beginning on day
48 and continuing for up to 30 weeks. Patients proceed to CNS therapy after day 49.

KEY RANDOMIZATION: Patients are randomized 1:1 to receive either IV-PEG or IM-EC
post-induction. Those who achieved a complete remission after induction therapy were assigned
a final risk group and were eligible to participate in the randomization. The randomization
was stratified by final risk group.

NOTE: Ph+ ALL patients did not participate in asparaginase randomization but were directly
assigned to receive IM-EC during post-induction therapy. Patients who were eligible but
declined randomization were also directly assigned to receive IM-EC. Patients who developed
severe pancreatitis (defined as symptoms persisting for >72 h) during induction were not
eligible for randomization and received no further doses of asparaginase. Patients who had
hypersensitivity to IV-PEG during induction were also ineligible for randomization, but
received twice-weekly IM-EC (25 000 IU/m2) during the post-induction treatment phases.

CNS

- CNS therapy (SR patients): Patients receive vincristine IV on day 1; oral mercaptopurine
once daily on days 1-14; oral dexamethasone twice daily on days 1-5; and TIT twice
weekly for 2 weeks. Patients also receive IV-PEG OR IM-EC as above beginning on day 1
and continuing for up to 30 weeks. Patients proceed to consolidation II after day 21.

- CNS therapy (HR and VHR patients): Patients receive vincristine, mercaptopurine,
dexamethasone, and TIT as in the SR group. Patients also receive dexrazoxane
hydrochloride IV over 15 minutes followed by DOX IV over 15 minutes on day 1. HR
patients also receive IV-PEG OR IM-EC as above beginning on day 1 and continuing for up
to 30 weeks. VHR patients continue to receive IV-PEG OR IM-EC as per consolidation I
treatment. Patients proceed to consolidation II after day 21.

NOTE: Patients with WBC > 100,000/mm³, T-cell disease, and/or CNS-3 at diagnosis or CNS-2 at
end of remission induction therapy also undergo cranial radiation therapy daily for 8 or 10
days.

CONSOLIDATION II

- Consolidation II (SR patients): Patients receive vincristine IV on day 1; oral
dexamethasone twice daily on days 1-5; and oral mercaptopurine once daily on days 1-14.
Treatment repeats every 21 days until IV-PEG OR IM-EC is completed. Patients also
receive MTX IV or IM 1 day after each IV-PEG OR IM-EC dose and TIT every 9 weeks for 6
doses and then every 18 weeks thereafter.

- Consolidation II (HR and VHR patients): Patients receive vincristine, dexamethasone, and
mercaptopurine as in the SR group. Patients also receive dexrazoxane hydrochloride IV
over 15 minutes followed by DOX IV over 15 minutes on day 1. Treatment repeats every 21
days until IV-PEG OR IM-EC is completed. Patients also receive MTX IV or IM as in the SR
group and TIT every 9 weeks for 6 doses and then every 18 weeks thereafter OR TIT every
18 weeks.

CONTINUATION

- Continuation therapy: After completion of all consolidation therapy, all patients
receive vincristine IV on day 1; oral dexamethasone twice daily on days 1-5; oral
mercaptopurine once daily on days 1-14; and MTX IV or IM on days 1, 8, and 15. Treatment
repeats every 21 days for up to 24 months (102 weeks) after achieving CR. Patients
continue to receive TIT as in consolidation II until completion of therapy.

OBJECTIVES:

Primary

- To determine the relative toxicity of IV PEG asparaginase and IM E.coli asparaginase in
children with acute lymphoblastic leukemia (ALL)

Secondary (reported)

- To explore the relative efficacy of IV PEG asparaginase and IM E.coliasparaginase

- To determine the rate of infections (episodes of bacteremia and disseminated fungal
infections) during the remission induction phase

- To compare trough serum asparaginase enzyme levels, asparagine levels and
antiasparaginase antibody levels

- To evaluate the outcome of patients based upon MRD status after 28 days of multiagent
chemotherapy within the context of a regimen which intensifies treatment for B-lineage
patients with MRD levels >0.001 at the end of remission induction (day 32 MRD status
used)

- To evaluate the outcome of patients based upon bone marrow morphology after 14 days of
multiagent chemotherapy (day 18 marrow morphology status used)

- To determine the efficacy of CNS-directed treatments

Secondary (not reported)

- To compare antiasparaginase antibody levels (not available due to problems with the
assay)

- To correlate trough enzyme levels with outcome (toxicity, relapse)

- To determine CNS-related toxicity of CNS-directed treatments (data is not mature on late
neurocognitive impairments in long-term survivors)

- To determine the efficacy and CNS-related toxicity (acute and long-term) of the HR
regimen in which a subset of HR patients (B-lineage, CNS-1 or CNS-2, WBC <100,000/m3)
are treated with intensive intrathecal chemotherapy and the remainder are treated with
12 Gy cranial radiation (with intrathecal chemotherapy)

- To determine the efficacy and CNS-related toxicity (acute and long-term) of intensive
intrathecal therapy in SR patients

- To determine the prognostic significance of asparaginase antibody formation

- To compare randomized treatment groups using health-related quality-of-life analysis
(connected with a separate protocol 06-373)

- To investigate the association of dietary antioxidant micronutrient intake with the rate
of infections (episodes of bacteremia and disseminated fungal infections) during
remission induction therapy and the Consolidation IA phase

- To determine the relationship of dietary calcium intake with risk for development of
fractures during the continuation phase of therapy

- To evaluate the association of dietary intake of specific nutrients with
treatment-related toxicities during treatment

- To evaluate the outcome of patients based upon MRD status after 14 days of multiagent
chemotherapy and at various other timepoints while on treatment every 18 weeks after
achieving complete remission and at the completion of all chemotherapy

- To determine the prognostic significance of response to remission induction chemotherapy
as measured by morphologic and minimal residual disease (MRD) measures within the
context of DFCI ALL Consortium protocol therapy (data limited due to response outcomes)

- To compare rate of infection during remission induction in patients treated with a less
intensive induction regimen on Protocol 05-01 (low-dose instead of high-dose
methotrexate) with that of patients treated on prior DFCI ALL Consortium Protocol 00-01
(induction regimen included high-dose methotrexate)

- To determine the concordance of MRD quantification using multi-parameter flow cytometry
and PCR techniques

- To determine the prognostic significance of gene expression programs in childhood ALL
and identify new targets for specific therapies

- To identify clinically relevant gene expression signatures in leukemia cells

- To identify gene expression signature in leukemia cells at diagnosis that predicts
peripheral blood response to the steroid prophase

- To identify gene expression changes in leukemia cells induced by steroid treatment

- To determine the frequency and type of tyrosine kinase mutations in childhood ALL and
identify new targets for specific therapies

- To explore the potential relationship between abnormal glucose homeostasis during
therapy and the development of obesity, as well as the potential relationship between
obesity and the age of pubertal onset (assessed in patients treated at DFCI/CHB only)

- To characterize the degree of hyperglycemia and insulin resistance in patients receiving
therapy for childhood ALL

- To characterize the degree of insulin resistance and obesity after the completion of
therapy for childhood ALL

DISEASE CHARACTERISTICS:

- Diagnosis of acute lymphoblastic leukemia (ALL)

- No known mature B-cell ALL, defined by the presence of any of the following:

- Surface immunoglobulin

- L3 morphology

- t(8;14)(q24;q32)

- t(8;22)

- t(2;8)

- T-cell surface markers and t(8;14)(q24;q11) allowed

- No secondary ALL

PATIENT CHARACTERISTICS:

- No known HIV positivity

- Not pregnant or nursing

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

- No prior therapy except steroids of ≤ 1 week in duration and/or emergent radiation
therapy to the mediastinum

- Patients treated with steroids within the past 7 days will not receive steroid
prophase during study treatment