Inclusion Criteria:

- Subjects with a diagnosis of CD20 and CD22-positive, follicular lymphoma, who have
received 1 or 2 prior regimens, at least 1 of which should have contained
administration of rituximab (either as a single agent or in combination).

- Age 18 years or older.

- ECOG performance status <= 2.

- ANC >= 1.5 x 10^9/L (1500/mL) and platelets >= 75 x 10^9/L (75,000/mL), serum
creatinine <= 1.5 x ULN and urine protein to creatinine ratio of <= 0.5, total
bilirubin <= 1.5 x ULN, AST and ALT <= 2.5 x ULN.

- At least 1 measurable disease lesion that is >= 1.5 cm x 1.5 cm by CT or MRI, in an
area of no prior radiation therapy, or documented progression in an area that was
previously irradiated.

Exclusion Criteria:

- Subjects with clinical evidence of transformation to a more aggressive subtype of
lymphoma or grade 3b follicular lymphoma.

- Subjects whose disease is rituximab refractory, meaning that they did not have a CR
or PR, or that they experienced disease progression within 6 months from the
initiation of the rituximab or rituximab containing treatment regimen administered
immediately preceding study enrollment.