Inclusion Criteria:

          -  Histopathologically confirmed diagnosis of DLBCL of the non-GCB DLBCL subtype via the
             Hans algorithm

          -  No prior treatment except a prior limited-field radiotherapy, a short course of
             glucocorticoids =< 25 mg daily of prednisone equivalent which must cease prior to day
             1 of cycle 1, and/or 1 dose of cyclophosphamide 750 mg/m2 for an urgent lymphoma
             related problem at diagnosis (e.g. epidural cord compression, superior vena cava
             syndrome)

          -  Patient or durable power of attorney (DPA) for healthcare must be able to understand
             and voluntarily sign an Institutional Review Board (IRB)-approved informed consent
             form

          -  Age >= 18 years at the time of signing the informed consent

          -  Patients must have bi-dimensional measurable disease, as defined as radiographically
             apparent disease with the longest dimension of >= 1.5 cm

          -  Patients with performance status of =< 3 (3 only allowed if decline in status is
             deemed related to lymphoma and felt potentially reversible by the treating physician)

          -  Serum bilirubin < 1.5 x upper limit of normal (ULN) except in patients with Gilbert's
             syndrome as defined by > 80% unconjugated bilirubin who must have a serum bilirubin of
             < 4 x ULN

          -  Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT]) and
             alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 3 x
             ULN or < 5 x ULN if hepatic metastases are present

          -  Absolute neutrophil count (ANC) > 1000/mm^3 unless deemed related to lymphoma
             involvement in the bone marrow and felt potentially reversible by the treating
             physician

          -  Platelets > 100,000/mm^3 unless deemed related to lymphoma involvement in the bone
             marrow and felt potentially reversible by the treating physician

          -  Calculated creatinine clearance >= 30 ml/min by Cockcroft-Gault formula

          -  Patients must be willing to receive transfusions of blood products

          -  All study participants must be registered into the mandatory Revlimid Risk Evaluation
             and Mitigation Strategy (REMS) program, and be willing and able to comply with the
             requirements of the REMS program

          -  Women of childbearing potential must have a negative serum (beta-human chorionic
             gonadotropin [beta-hCG]) at screening and must adhere to the scheduled pregnancy
             testing as required in the Revlimid REMS program

          -  Women of childbearing potential and men who are sexually active with a woman of
             childbearing potential must be practicing a highly effective method of during and
             after the study (12 months after study drug for women and 3 months after study drug
             for men), consistent with local regulations regarding the use of birth control methods
             for subjects participating in this clinical study. Men must agree to not donate sperm
             during and for up to 3 months after their conclusion of therapy on study

          -  Able to take aspirin (81 mg) daily or alternative therapy as prophylactic
             anticoagulation

        Exclusion Criteria:

          -  Any serious medical condition including but not limited to uncontrolled hypertension,
             uncontrolled congestive heart failure within past 6 months prior to screening (class 3
             [moderate] or class 4 [severe] cardiac disease as defined by the New York Heart
             Association Functional classification), uncontrolled or symptomatic arrhythmias with
             corrected QT interval (QTc) > 480 msec at screening, uncontrolled diabetes mellitus,
             active/symptomatic coronary artery disease, chronic obstructive pulmonary disease
             (COPD), left ventricular ejection fraction (LVEF) less than 40%, renal failure,
             uncontrolled autoimmune hemolytic anemia or idiopathic thrombocytopenic purpura active
             infection, history of invasive fungal infection, moderate to severe hepatic disease
             (Child Pugh class B or C), active hemorrhage, laboratory abnormality, or psychiatric
             illness that, in the investigators opinion places the patient at unacceptable risk and
             would prevent the subject from signing the informed consent form. Patients with
             history of cardiac arrhythmias should have cardiac evaluation and clearance

          -  Pregnant or lactating females

          -  Known hypersensitivity to lenalidomide or thalidomide, acalabrutinib, tafasitamab,
             rituximab, vincristine, doxorubicin, cyclophosphamide, or prednisone

          -  Known human immunodeficiency virus (HIV) infection. Hepatitis B or C serologic status:
             subjects who are hepatitis B core antibody (anti-HBc) positive and who are hepatitis B
             surface antigen (HBsAg) negative will need to have a negative DNA polymerase chain
             reaction (PCR) and must be willing to undergo DNA PCR testing during the study to be
             eligible. Those who are HBsAg positive or hepatitis B DNA PCR positive will be
             excluded. Subjects who are hepatitis C antibody positive will need to have a negative
             DNA PCR result to be eligible. Those who are hepatitis C DNA PCR positive will be
             excluded

          -  All patients with known central nervous system involvement with lymphoma

          -  Diagnosis of prior malignancy within the past 2 years with the exception of
             successfully treated basal cell carcinoma, squamous cell carcinoma of the skin,
             carcinoma "in situ" of the cervix or breast. History of other malignancies are allowed
             if in remission (including prostate cancer patients in remission from radiation
             therapy, surgery or brachytherapy), not actively being treated, with a life expectancy
             > 3 years

          -  Significant neuropathy (grades 2 or grade 1 with pain) within 14 days prior to
             enrollment

          -  Contraindication to any of the required concomitant drugs or supportive treatments or
             intolerance to hydration due to preexisting pulmonary or cardiac impairment including
             pleural effusion requiring thoracentesis or ascites requiring paracentesis not due to
             lymphoma

          -  Patients with active pulmonary embolism or deep vein thrombosis (diagnosed within 30
             days of study enrollment)

          -  Patients with severe bradycardia (heart rate < 40 bpm, hypotension, lightheadedness,
             syncope)

          -  Major surgery within 4 weeks of study entry, or wound that is not healed from prior
             surgery or trauma

          -  History of stroke or intracranial hemorrhage within 6 months prior to study entry

          -  Requires anticoagulation with warfarin or equivalent vitamin K antagonists

          -  Requires chronic treatment with strong CYP3A inhibitors

          -  Vaccinated with live, attenuated vaccines within 4 weeks of study entry

          -  Active bleeding or history of bleeding diathesis (e.g., hemophilia or von Willebrand
             disease)

          -  Uncontrolled AIHA (autoimmune hemolytic anemia) or ITP (idiopathic thrombocytopenic
             purpura)

          -  Presence of a gastrointestinal ulcer diagnosed by endoscopy within 3 months before
             screening

          -  Prothrombin time (PT)/international normalized ratio (INR) or activated partial
             thromboplastin time (aPTT) (in the absence of lupus anticoagulant) > 2 x ULN

          -  Requires treatment with proton pump inhibitors (e.g., omeprazole, esomeprazole,
             lansoprazole, dexlansoprazole, rabeprazole, or pantoprazole). Note: Subjects receiving
             proton pump inhibitors who switch to H2-receptor antagonists or antacids are eligible
             for enrollment to this study

          -  Concurrent participation in another therapeutic clinical trial