Study of Veltuzumab and 90Y-Epratuzumab in Relapsed/Refractory, Aggressive NHL

The treatment portion of this study consists of study drug administrations each week for
four weeks in a row (a total of 4 treatment days). Patients will then return at intervals up
to 12 weeks for blood samples and for evaluations to see if their disease responded and to
monitor any adverse effects related to treatment. Some blood tests may then need to be
repeated at least a few times and/or until any abnormal findings at earlier evaluations have
resolved. Otherwise, patients will continue to be evaluated every 3 months for two years,
then every 6 months up to 5 years or until the disease worsens. Participation in the study
will end when NHL disease worsens.

Inclusion Criteria:

- Male or female, >18 years old

- Histological diagnosis of CD20+ B-cell NHL, with DLBCL or other aggressive lymphomas
by WHO lymphoma criteria including mantle cell lymphoma and transformed follicular
lymphoma.

- Failed at least one prior standard treatment regimen for NHL

- If DLBCL, either received, ineligible for or refused high-dose chemotherapy with stem
cell transplant

- Measurable NHL disease by CT, with at least one lesion >1.5 cm in one dimension

- Adequate performance status (>70 Karnofsky scale, 0-1 ECOG)* with an estimated life
expectancy of at least 6 months

- Laboratory parameters:

- Adequate hematology (Hemoglobin >/= 10 g/dL, ANC >/= 1.5 ´ 109/L, platelets
>/=100 x 109/L) without ongoing transfusional support

- Adequate renal and liver function (creatinine and bilirubin and ALT
- Otherwise,
- 3 months beyond any prior rituximab or veltuzumab treatment, 12 weeks beyond
autologous stem cell transplant and 4 weeks beyond chemotherapy, other experimental
treatments, or any radiation therapy to the index lesion(s).

- Screened for hepatitis B (no time limit) and negative by tests included in NCCN
guidelines (hepatitis B surface antigen/antibodies, core antigen/antibodies,
hepatitis B e-antigen).

- Patients of childbearing potential must be willing to practice birth control during
the study until at least 12 weeks after last veltuzumab infusion; women of
childbearing potential must have a negative urine or serum pregnancy test to enter
the study.

- Ability to provide signed, informed consent

Exclusion Criteria:

- Pregnant or lactating women. Women of childbearing potential are required to have a
negative pregnancy test

- NCI CTC Grade 3 or 4 infusion reaction to prior anti-CD20 antibodies (rituximab,
veltuzumab, etc.)

- A known anti-antibody response to prior antiCD20 antibodies (HACA positive, HAHA
positive, etc)

- Prior radioimmunotherapy, including Zevalin or Bexxar.

- Prior high-dose chemotherapy with peripheral blood stem cell transplant.

- Prior therapy with other human or humanized monoclonal antibodies, unless HAHA
tested and negative

- Primary CNS lymphoma, HIV lymphoma or transformed lymphoma, or presence of
symptomatic CNS metastases or carcinomatous meningitis.

- Rituximab or veltuzumab resistant, defined as having progressed during or within
6 months of any prior rituximab or veltuzumab treatment.

- Bulky disease by CT, defined as any single mass >10 cm in its greatest diameter

- Bone marrow involvement ≥25%

- Prior external beam radiation therapy to >30% bone marrow.

- Pleural effusion with positive cytology for lymphoma

- Patients known to be HIV positive, hepatitis B positive, or hepatitis C positive

- Known autoimmune disease or presence of autoimmune phenomena.

- Evidence of infection or requiring antibiotics within 7 days.

- Use of systemic corticosteroids within 2 weeks, except low dose regimens
(prednisone, <20 mg/day, or equivalent) which may continue if unchanged.

- Prior malignancies (other than non-melanoma skin cancer or carcinoma in situ of
the cervix) unless disease free for 5 years.

- Prior malignancy with less than a 5-year disease-free interval, excluding
nonmelanoma skin cancers and carcinoma in situ of the cervix.

- Other concurrent medical or psychiatric conditions that, in the Investigator's
opinion, may be likely to confound study interpretation or prevent completion of
study procedures and follow-up examinations