⁃ Informed consent

• Ability to understand the purpose and risks of the study and capable of giving signed informed consent which includes:

∙ Compliance with the requirements and restrictions listed in the informed consent form (ICF).

‣ Authorization to use protected health information/data \[in accordance with the General Data Protection Regulation (GDPR)\].

• Provision of signed and dated, written ICF prior to any mandatory study specific procedures, sampling, and analyses

• Willing and able to participate in all required evaluations and procedures in this study protocol, including swallowing capsules and tablets without difficulty.

• Age/Sex

• Men and women \>80 years of age or \>60 up to 80 years of age and ineligible for full dose R-CHOP according to investigator assessment\*.

• We recommend classifying patients aged 61-80 as full-dose R-CHOP ineligible if they fulfill one of the following criteria: ADL \<5, IADL \<6, CIRS-G ≥1 score = 3, or \> 8 score = 2.

• Male patients who are sexually active with women of childbearing potential (definitions see section 17.8) must agree to use highly effective forms of contraception with the addition of a barrier method (condom) during the study (see section 17.8.1) as well as to the restrictions mentioned in section 9.13.

• Female patients of childbearing potential (definitions see 17.8) who are sexually active must agree to use highly effective forms of contraception while on the study as well as to the restrictions mentioned in section 9.13.

• Disease characteristics

• Histologically proven, previously untreated CD20+ diffuse large B-cell lymphoma (DLBCL) according to the 2017 WHO classification including:

∙ diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS)

‣ primary cutaneous DLBCL leg type

‣ intravascular large B-cell lymphoma

‣ EBV+ DLBCL, NOS

‣ HHV8+DLBCL, NOS

‣ primary mediastinal (thymic) large B-cell lymphoma

‣ B-cell lymphoma, with intermediate features between DLBCL and classical Hodgkin lymphoma

‣ follicular lymphoma grade 3B

‣ high-grade B-cell lymphoma, NOS

∙ high-grade B-cell lymphoma, with MYC and BCL2 and/or BCL6 rearrangements

∙ T-cell/histiocyte-rich large B-cell lymphoma

∙ DLBCL associated with chronic inflammation

∙ ALK+ large B-cell lymphoma

∙ large B-cell lymphoma with IRF4 rearrangement Please note: patients in whom indolent lymphoma is diagnosed concurrently with the one of the above listed diagnoses can also be included.

• Disease Stage I with bulk ≥7.5cm, II, III or IV according to Ann Arbor Classification Type of patient and clinical characteristics

• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2. An ECOG Score of 3 is acceptable only if this is directly attributable to lymphoma.

⁃ Meet the following laboratory parameters:

• Absolute neutrophil count (ANC) ≥ 1500 cells/µl or platelet count ≥ 100.000/µl unless directly attributable to lymphoma.

∙ Serum AST and ALT ≤3 x upper limit of normal (ULN) unless directly attributable to lymphoma.

∙ Total bilirubin ≤1.5 x ULN, unless directly attributable to Gilbert's syndrome or lymphoma.

∙ Estimated creatinine clearance of ≥30 mL/min, calculated by Cockcroft-Gault (using actual body weight) (if male, \[140-Age\] x Mass \[kg\] / \[72 x creatinine mg/dL\]; multiply by 0.85 if female), or serum creatinine ≤2.5 x ULN.