Inclusion Criteria:

• Subjects with CD20 positive aggressive NHL including DLBCL, transformed FL & grade 3b FL.

Refractory to, or relapsed following, first-line treatment with rituximab combined with anthracycline-based chemotherapy as defined by the protocol.

• CT with involvement of 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.
• Baseline FDG-PET scans must demonstrate positive lesions compatible with CT defined anatomical tumor sites.
• Age 18 yrs or older.
• ECOG performance status of 0, 1 or 2.
• Eligible for high dose chemotherapy and ASCT.
• Resolution of toxicities from first-line therapy to grade ≥1.
• Signed written informed consent.

Exclusion Criteria:

• Previous cancer therapy for lymphoma, with the exception of required rituximab/ anthracycline-based chemotherapy or limited field radiotherapy.
• Any anti-cancer therapy, except limited field radiotherapy, within 4 weeks prior to start of study therapy.
• Chronic Glucocorticoid use (limited acute use is allowed and defined by the protocol).
• History of significant cerebrovascular disease.
• Abnormal/ inadequate WBC count, liver, and kidney function.
• Clinically significant cardiac disease, active or chronic infections, serious significant diseases, other cancer within last 5 years.
• Known or suspected hypersensitivity to study treatments.
• Prior treatment with anti-CD20 monoclonal antibodies, at any time, or treated with other monoclonal antibodies within 3 months prior to start of study therapy, with the exception of rituximab in both instances.
• Inability to comply with the protocol activities.
• Pregnant or lactating women or female patients of child-bearing potential (or male patients with such partners) not willing to use adequate contraception during and up to 1 year following dosing completion.