Imatinib Completed Phase 1 / 2 Trials for B-cell Childhood Acute Lymphoblastic Leukemia / Untreated Childhood Acute Lymphoblastic Leukemia / Philadelphia Chromosome Positive Adult Precursor Acute Lymphoblastic Leukemia / T-cell Childhood Acute Lymphoblastic Leukemia / L1 Adult Acute Lymphoblastic Leukemia / L1 Childhood Acute Lymphoblastic Leukemia / Philadelphia Chromosome Positive Childhood Precursor Acute Lymphoblastic Leukemia / L2 Adult Acute Lymphoblastic Leukemia / T-cell Adult Acute Lymphoblastic Leukemia / Philadelphia Chromosome Negative Adult Precursor Acute Lymphoblastic Leukemia / L2 Childhood Acute Lymphoblastic Leukemia / Untreated Adult Acute Lymphoblastic Leukemia / B-cell Adult Acute Lymphoblastic Leukemia / Acute Undifferentiated Leukemia (AUL) Treatment