An Open Label, Phase II Trial of Prophylactic Rituximab Therapy for Prevention of Chronic Graft Versus Host Disease After TLI/ARG Nonmyeloablative Allogeneic Stem Cell Transplantation

Inclusion Criteria:

(A) Patients age greater than 17 and less than 76. (B) CLL patients
with unmutated IgG VH gene status are immediately eligible and patients with mutated IgG
VH genes (>2% nucleotide change compared to somatic sequence) are eligible if they are
considered appropriate by their HSCT physician. CLL patients in complete remission
benefit most from allogeneic HSCT, and physicians will be encouraged to provide aggressive
chemotherapy prior to nonmyeloablative transplantation.

(C) MCL patients who their BMT physicians believe would benefit from allogeneic HSCT.

(D) Adequate renal (Cr < 2.4 mg/dl) and hepatic (Bilirubin < 3.0 mg/dl, AST < 100 IU)
function. Patients with lab results in excess of these can be enrolled with approval of
PI.

(E) Men and women of reproductive potential must agree to use an acceptable method of
birth control during treatment and for six months after completion of treatment.

(F) All subjects must provided written informed consent

Donor Inclusion Criteria (A) Genotypically or phenotypically HLA-identical. (B) Donor age
< 75 unless cleared by institutional P.I (C) Capable of giving written, informed consent.
(D) Donor must consent to PBSC mobilization with G-CSF and apheresis

Exclusion Criteria:(A) Patient age less than 18 or greater than 75 (B) Patient does not
have a 9/10 or 10/10 HLA identical donor (high resolution molecular genotyping at HLA A,
B, C and DrB1, and DQ) (C) Standard exclusions for any allogeneic transplantation
including: i. Pregnancy or lactation ii. Serious uncontrolled infection iii. HIV
seropositivity iv. Hepatitis B or C seropositivity v. Cardiac function: ejection fraction
<40% or uncontrolled cardiac failure vi. Pulmonary: DLCO <50% predicted vii. Liver
function abnormalities: elevation of bilirubin to >= 3 mg/dl and/or AST>100 viii. Renal:
creatinine >2.4 ix. Karnofsky performance score <= 60% x. Patients with poorly controlled
hypertension (SBP>150 or DBP>90 repeatedly). (D) Known life-threatening hypersensitivity
to Rituximab or other anti-B cell antibody is an exclusion criterion. Previous Rituximab
therapy is neither required, nor is it an exclusion criterion, but will be carefully
assessed and correlated with outcome.

(E) Inability to comply with the allogeneic transplant treatment. (F) Uncontrolled CNS
involvement with disease

Donor Exclusion Criteria (A) Identical twin (B) Any contra-indication to the
administration of subcutaneous G-CSF at a dose of 16mg/kg/d for five consecutive days (C)
Serious medical or psychological illness (D) Pregnant or lactating females (E) Prior
malignancy within the preceding five years, with the exception of non-melanoma skin
cancers.

(F) HIV seropositivity