Inclusion Criteria

Inclusion Criteria

- Patient with follicular lymphoma grade 1 - 2

- Refractory to rituximab given as monotherapy or in combination with any chemotherapy
or to rituximab given as maintenance treatment following R-chemo, defined as:

- failure to achieve at least PR to rituximab given as monotherapy or in combination
with any chemotherapy; or,

- disease progression while on rituximab (either given as monotherapy or in
combination with any chemotherapy or during rituximab maintenance treatment following
R-chemo); or,

- disease progression in responders within 6 months of the last dose of rituximab
(either given as monotherapy or in combination with any chemotherapy or after
rituximab maintenance treatment schedule following R-chemo)

- Tumor verified to be CD20+ positive from excisional lymph node biopsy

- CT scan in screening phase (based on local evaluation) showing:

- 2 or more clearly demarcated lesions with a largest diameter ≥ 1.5 cm, or

- 1 clearly demarcated lesion with a largest diameter ≥ 2,0 cm

- ECOG Performance Status of 0, 1, or 2

- Age ≥ 18 years

- Following receipt of verbal and written information about the study, the patient must
provide signed informed consent before any study related activity is carried out

Exclusion Criteria

- Previous autologous stem cell transplantation within 6 months

- Previous allogeneic stem cell transplantation

- More than 1 previous radio immunotherapy regimen

- Received radio immunotherapy within 3 months

- Received any Anti-cancer treatment within 4 weeks

- Received monoclonal antibodies, other than rituximab within 3 months

- Patients previously treated with anti-CD20 monoclonal antibodies, other than
rituximab

- Life expectancy less than 6 months