This is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial designed to compare the efficacy and safety of the humanized monoclonal anti CD19 antibody tafasitamab plus lenalidomide in addition to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) versus R-CHOP in previously untreated, high-intermediate and high-risk patients with newly-diagnosed DLBCL

Major Inclusion Criteria:

• Previously untreated patients with local biopsy-proven, CD20-positive DLBCL, including one of the following diagnoses by 2016 World Health Organization (WHO) classification of lymphoid neoplasms are eligible:

  1. DLBCL, NOS including GCB type, ABC type
  2. T-cell rich large BCL
  3. Epstein-Barr virus-positive DLBCL, NOS
  4. Anaplastic lymphoma kinase (ALK)-positive large BCL
  5. Human herpes virus-8 (HHV8)-positive DLBCL, NOS
  6. High-grade BCL with MYC and B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6) rearrangements (double-hit or triple-hit lymphoma). Please note: Patients must be appropriate candidates for R-CHOP. If an investigator deems a patient with a known double- or triple-hit lymphoma (HGBL) should be treated more aggressively (e.g. dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab [DA-EPOCH-R] or cyclophosphamide, vincristine, doxorubicin and dexamethasone (CVAD) followed by methotrexate and cytarabine [Hyper CVAD]), this patient would not be considered eligible for this study
  7. HGBL-NOS
  8. DLBCL coexistent with either follicular lymphoma (FL) of any grade, gastric MALT lymphoma or non-gastric MALT lymphoma
  9. FL grade 3b

• Availability of archival or freshly collected tumor tissue sent for retrospective central pathology review

• IPI status of 3 to 5 (for patients > 60 years of age) or aaIPI 2 to 3 (for patients ≤ 60 years of age)

• Diagnosis to treatment interval, defined as the time between the date of DLBCL diagnosis (date of the first biopsy specimen containing B Cell lymphoma according to the local pathology report) and the start of treatment (C1D1) ≤ 28 days

• ECOG performance status of 0, 1, or 2

• Left ventricular ejection fraction equal to or greater 50% as assessed by local echocardiography or cardiac multi-gated acquisition (MUGA) scan

• Adequate hematologic function

• Female participants: Agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods and refrain from breast feeding and donating eggs; agreement to ongoing pregnancy testing during the course of the study, and after study therapy has ended

• Male participants: agreement to remain abstinent (refrain from heterosexual intercourse) or use a condom and agreement to refrain from donating sperm

Major Exclusion Criteria:

• Any other histological type of lymphoma according to WHO 2016 classification of lymphoid neoplasms, e.g., primary mediastinal (thymic) large B-cell lymphoma, Burkitt's lymphoma, BCL, unclassifiable, with features intermediate between DLBCL and classical Hodgkin lymphoma (grey-zone lymphoma); primary effusion lymphoma; primary cutaneous DLBCL, leg type; primary DLBCL of the CNS; DLBCL arising from CLL or indolent lymphoma

• History of prior non-hematologic malignancy except for the following:

  1. Malignancy treated with curative intent and with no evidence of active disease present for more than 2 years before screening
  2. Adequately treated lentigo maligna melanoma without current evidence of disease or adequately controlled non-melanomatous skin cancer
  3. Adequately treated carcinoma in situ without current evidence of disease

• Any systemic anti-lymphoma and/or investigational therapy prior to the start of C1D1, except for permitted pre-phase treatment

• Contraindication to any of the individual components of R-CHOP, including prior receipt of anthracyclines

• Known CNS lymphoma involvement

• Known active systemic bacterial, viral, fungal, or other infection at screening, including patients with suspected active or latent tuberculosis (as confirmed by a positive interferon-gamma release assay)

• History or evidence of clinically significant cardiovascular, CNS and/or other systemic disease that in the investigator's opinion would preclude participation in the study or compromise the patient's ability to give informed consent