Tacrolimus and Methotrexate With or Without Sirolimus in Preventing Graft-Versus-Host Disease in Young Patients Undergoing Donor Stem Cell Transplant for Acute Lymphoblastic Leukemia in Complete Remission

Inclusion Criteria:

* Histologically or cytologically confirmed acute lymphoblastic leukemia (ALL) in second complete remission (CR2) (M1 bone marrow, \< 5% blasts by morphology) meeting the following criteria:

  * Intermediate risk relapsed ALL in CR2 (may receive matched sibling transplantation only) meeting 1 of the following criteria:

    * B-lineage ALL in CR2 after a late first bone marrow (BM) relapse (≥ 36 months after the initiation of primary chemotherapy) with or without associated extramedullary disease
    * B-lineage ALL in CR2 after a very early isolated extramedullary relapse (\<18 months from the initiation of primary chemotherapy)
  * High risk relapsed ALL in CR2 (may receive other related donor, unrelated donor, or matched sibling transplantation) meeting 1 of the following criteria:

    * In CR2 after an early first BM relapse (\< 36 months from initiation of primary chemotherapy)
    * T-lineage ALL in CR2 after a first BM relapse occurring at any time after initiation of primary chemotherapy
    * Philadelphia chromosome-positive ALL in CR2 after a first BM relapse occurring at any time after the initiation of primary chemotherapy
    * T-lineage ALL in CR2 after a very early isolated extramedullary relapse (\<18 months from the initiation of primary chemotherapy)
  * High risk de novo ALL in CR1 (may receive matched sibling, other related/unrelated BM/PBSC or unrelated CB transplantation) meeting 1 of the following criteria:

    * Patients with the presence of t(9;22) translocation (Ph+) detected by cytogenetic or PCR analysis at initial diagnosis. For patients on AALL0622, the criteria for transplant are 1) any patient with Ph+ ALL with an available matched sibling donor or 2) any patient with Ph+ ALL that is defined as high risk (MRD \> 1% Day 29 or MRD \> 0.01% end-Consolidation Block 2) with any available donor, related or unrelated. Patients enrolled on AALL0622 are only eligible if they follow this algorithm.
    * Patients with the presence of extreme hypodiploidy (\< 44 chromosomes or DNA index of \< 0.81) detected by cytogenetic/ploidy analysis at initial diagnosis.
    * Patients with the presence of 11q23 (MLL) rearrangements detected by cytogenetic or PCR analysis at initial diagnosis who are slow early responders (M2/M3 at Day 14 or MRD \> 0.1% at Day 29).
* Enrolled on an appropriate COG relapsed ALL clinical trial after completing the required study therapy (i.e., minimum 1 re-induction course (4-6 weeks) and 1 round of intensive consolidation chemotherapy (3-6 weeks). Patients with high risk ALL in CR1 are eligible as soon as they have achieved a CR.

  * Patients not on a COG relapsed ALL clinical trial are eligible provided they have received ≥ 1 round of re-induction lasting 4-6 weeks and 1 round of intensive consolidation chemotherapy lasting 3-6 weeks
* No B-cell ALL L3 morphology with evidence of myc translocation by molecular or cytogenetic technique
* No Down syndrome
* No evidence of active CNS or other extramedullary disease (i.e., no CNS2)
* Karnofsky performance status (PS) 60-100% (for patients \> 16 years of age) OR Lansky PS 60-100% (for patients ≤ 16 years of age)
* Shortening fraction ≥ 27% by echocardiogram OR ejection fraction ≥ 50% by radionuclide angiogram
* ALT or AST \< 5 times upper limit of normal
* Bilirubin \< 2.5 mg/dL (unless an increase is attributable to Gilbert's syndrome)
* Creatinine clearance OR radioisotope glomerular filtration rate ≥ 70 mL/min
* FEV\_1 ≥ 60% by pulmonary function tests (PFTs)
* FVC ≥ 60% by PFTs
* DLCO ≥ 60% by PFTs
* For children who are unable to cooperate for PFTs all of the following criteria must be met:

  * No evidence of dyspnea at rest
  * No exercise intolerance
  * No requirement for supplemental oxygen therapy
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* No HIV or uncontrolled fungal, bacterial, or viral infection

  * Fungal infection acquired during induction therapy allowed provided there is a significant response to antifungal therapy with minimal or no evidence of disease by CT scan
* Other concurrent immunosuppressants allowed
* No prior allogeneic or autologous stem cell transplantation
* No prior or concurrent voriconazole unless prior voriconazole therapy is completed or a different agent is substituted for voriconazole prior to study entry
* No concurrent grapefruit juice during sirolimus administration