A Phase 3 Study to Assess Efficacy and Safety of Tafasitamab Plus Lenalidomide and Rituximab Compared to Placebo Plus Lenalidomide and Rituximab in Patients With Relapsed/Refractory (R/R) Follicular Lymphoma or Marginal Zone Lymphoma.

Open to people ages 18 years and up

• Histologically confirmed Grade 1, 2, or 3a FL or nodal MZL, splenic MZL, or extra nodal MZL
• Willingness to avoid pregnancy or fathering children
• In the opinion of the investigator, be able and willing to receive adequate mandatory prophylaxis and/or therapy for thromboembolic events (eg, aspirin 70-325 mg daily or low-molecular-weight heparin)
• Previously treated with at least 1 prior systemic anti-CD20 immunotherapy or chemo-immunotherapy
• Documented relapsed, refractory, or PD after treatment with systemic therapy
• ECOG performance status of 0 to 2

• Women who are pregnant or breastfeeding.
• Any histology other than FL and MZL or clinical evidence of transformed lymphoma
• Prior non-hematologic malignancy
• Congestive heart failure
• HCV positivity, chronic HBV infection or history of HIV infection
• Active systemic infection
• CNS lymphoma involvement
• Any systemic anti-lymphoma and/or investigational therapy within 28 days prior to the start of Cycle 1
• Prior use of lenalidomide in combination with rituximab