Trial of Sirolimus and Methotrexate in Relapsed/Refractory Lymphoblastic Leukemia and Lymphoma

At present children who have bone marrow or combined bone marrow and extramedullary relapses of acute leukemia while on therapy have 5-20% of long-term survival. Newer, targeted agents need to be identified and integrated into the present cytotoxic chemotherapy regimens. Biologically targeted cancer agents, including signal transduction inhibitors like mammalian target of rapamycin inhibitors (MTIs), have shown great promise in treating hematologic malignancies. A Phase 1 trial of sirolimus (an MTI) alone performed at CHOP has been well tolerated with no DLTs and has evidence of hitting the biologic target. While signal transduction inhibitors may be efficacious as single agents, it is more likely that these targeted agents will demonstrate greater efficacy in combination with other cytotoxic agents.Based upon pre-clinical humanized ALL mouse models we propose to study the toxicity and efficacy of adding sirolimus to oral methotrexate in relapsed and refractory patients. Patients \< 25 years of age, at time of enrollment, with second or greater relapse of ALL or NHL (lymphoblastic lymphoma or peripheral T-cell lymphoma) are eligible. ALL patients must have at least 10% blasts in their marrow and NHL patients must have radiologic or physical evidence of recurrence. Patients will be started on daily oral sirolimus that is dosed based upon goal trough levels and weekly oral methotrexate. All therapy can be done as an outpatient.