Rituximab to the Preparative Regimen of Etoposide and Total Body Irradiation in Acute Lymphoblastic Leukemia

Inclusion Criteria:

* Patients with biopsy-proven ALL in remission or relapse.
* Adequate renal function, as defined by estimated serum creatinine clearance \>50 ml/min and/or serum creatinine \<1.8 mg/dL.
* Adequate hepatic function, as defined by aspartate aminotransferase (AST) or serum glutamic oxaloacetic transaminase (SGOT) \<3 \* upper limit of normal; serum bilirubin and alkaline phosphatase \<2 \* upper limit of normal, or considered not clinically significant.
* Adequate pulmonary function with Forced Expiratory Volume in One Second (FEV1), forced vital capacity (FVC) and Carbon Monoxide Diffusing Capacity (DLCO) at least 45% of expected corrected for hemoglobin.
* Adequate cardiac function with left ventricular ejection fraction at least 45%. No uncontrolled arrhythmias or symptomatic cardiac disease.
* Zubrod performance status \<2.
* Patients must have a related, genotypically human leukocyte antigens (HLA) identical donor, or they must have a related or unrelated donor who is at least a 9/10 HLA match by high resolution typing.
* Female patient must not be pregnant and have negative pregnancy test.
* Patient and donor should be willing to participate in the study by providing written consent.

Exclusion Criteria:

* Patients with unresolved grade 3 or greater non-hematologic toxicity from previous therapy. Patients with grade 2 toxicity will be eligible at the discretion of the principal investigator (PI).
* Patients with active central nervous system (CNS) disease.
* Evidence of acute or chronic active hepatitis or cirrhosis.
* Uncontrolled infection, including Human immunodeficiency virus (HIV) or Human T-lymphotropic virus Type I (HTLV-1) infection.
* Patients greater than 60 years-old.
* Prior autologous or allogeneic hematopoietic stem cell transplant.