DISEASE CHARACTERISTICS:

* Morphologically confirmed precursor B-cell acute lymphoblastic leukemia (ALL) (non T-cell)

* Must have evidence of disease in bone marrow or peripheral blood

* Immunophenotyping of the blood or marrow lymphoblasts must be performed to determine lineage (B cell, T cell, or mixed B/T cell)
* Must have ≥ 5% lymphoblasts present in the blood or bone marrow
* At least 20% of marrow and/or peripheral blood lymphoblasts must be CD22+ by flow cytometry

* Co-expression of myeloid antigens (CD13 and CD33) allowed
* Patients with only extramedullary disease in the absence of bone marrow or blood involvement are not eligible
* Philadelphia (Ph) chromosome-negative disease

* Patients with unknown Ph status by cytogenetics or FISH and unknown BCR/ABL status by PCR are eligible for study registration, but must be removed from study therapy if found to be Ph+ or BCR/ABL+ after study registration
* Refractory to a standard induction regimen that included vincristine and prednisone or high-dose cytarabine or mitoxantrone OR relapsed after successful prior induction therapy

* Any number of prior induction therapies or any number of remissions achieved are allowed
* No M0 acute myeloid leukemia, mixed lineage leukemia, or L3 (Burkitt) leukemia
* No active CNS involvement by clinical evaluation

* Patients with a documented history of CNS involvement of ALL or with clinical signs or symptoms consistent with CNS involvement of ALL must undergo a lumbar puncture that is negative for CNS involvement of ALL
* Patients < 22 years of age must be willing to receive prophylactic intrathecal chemotherapy
* Must be registered on SWOG-9007 "Cytogenetic Studies in Leukemia Patients" (closed as of 07/01/2010)

PATIENT CHARACTERISTICS:

* Zubrod performance status 0-2
* Serum creatinine ≤ 1.0 mg/dL OR glomerular filtration rate > 60 mL/min
* AST and ALT ≤ 2.5 times upper limit of normal (ULN)
* Alkaline phosphatase ≤ 2.5 times ULN
* Bilirubin ≤ 1.5 times ULN
* Not pregnant or nursing
* Fertile patients must use effective contraception during and for ≥ 6 months after completion of study treatment
* HIV-positive patients are eligible (at the discretion of the investigator) provided the following criteria are met:

* No history of AIDS-defining conditions
* CD4 cell count > 350/mm³
* If on antiretroviral agents, must not include zidovudine or stavudine
* Willing to receive prophylaxis for pneumocystis jirovecii pneumonia during study therapy (regardless of CD4 cell count) until the CD4 cell count is > 200/mm³ after completion of study treatment
* Prior malignancy (other than ALL) allowed provided it is in remission and there are no plans to treat the malignancy at the time of study registration
* No uncontrolled systemic fungal, bacterial, viral, or other infection, defined as exhibiting ongoing signs or symptoms related to the infection with no improvement despite appropriate antibiotics or other treatment
* No neuropathy (cranial, motor or sensory) ≥ grade 2

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* Any number of prior therapies allowed
* More than 90 days since prior allogeneic bone marrow transplant (BMT)

* No concurrent immunosuppression therapy for the treatment of graft-vs-host disease (GVHD)
* No acute GVHD ≥ grade 2, moderate or severe limited chronic GVHD, or extensive chronic GVHD of any severity
* Prior autologous BMT allowed

* No concurrent immunosuppression therapy for the treatment of GVHD
* More than 14 days since prior chemotherapy, investigational agents, or major surgery and recovered

* Maintenance therapy with steroids, vincristine, and/or anti-metabolite agents, including but not limited to, mercaptopurine, thioguanine, and methotrexate allowed
* Concurrent hydroxyurea to reduce WBC to a reasonable level (as deemed by the treating physician) allowed
* No prior clofarabine or epratuzumab
* No other concurrent cytotoxic therapy or investigational therapy
* No concurrent alternative medications (e.g., herbal or botanical medications for anticancer purposes)
* Concurrent participation on SWOG-S9910 "Leukemia Centralized Reference Laboratories and Tissue Repositories, Ancillary" allowed (closed as of 07/01/2010)