Inclusion Criteria:

- Documented indolent or transformed B-Cell NHL indolent NHL: follicular B-Cell
lymphoma, diffuse small lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal
zone lymphoma

- Documented refractory disease to rituximab therapy, given as a single agent or in
combination (defined as no response, or progression within 6 months of completing
rituximab treatment.)

- Age of at least 18 years at Screening Visit (Site specific requirement may differ)

Exclusion Criteria:

- Previous chemotherapy or immunotherapy within 3 weeks prior to entering the study (6
weeks for nitrosoureas or mitomycin) or failure to recover from adverse events due to
any agents administered previously.

- Use of investigational agents within 28 days of study

- History of prior high dose chemotherapy with allogeneic stem cell support