Testing Drug Treatments After CAR T-cell Therapy in Patients With Relapsed/Refractory Diffuse Large B-cell Lymphoma
Purpose
This phase II trial tests whether mosunetuzumab and/or polatuzumab vedotin helps benefit patients who have received chemotherapy (fludarabine and cyclophosphamide) followed by chimeric antigen receptor (CAR) T-cell therapy (tisagenlecleucel, axicabtagene ciloleucel, or lisocabtagene maraleucel) for diffuse large B-cell lymphoma that has come back (recurrent) or that does not respond to treatment (refractory) or grade IIIb follicular lymphoma. Mosunetuzumab is a monoclonal antibody that may interfere with the ability of cancer cells to grow and spread. Polatuzumab vedotin is a monoclonal antibody, called polatuzumab, linked to a drug called vedotin. Polatuzumab is a form of targeted therapy because it attaches to specific molecules (receptors) on the surface of cancer cells, and delivers vedotin to kill them. Chemotherapy drugs, such as fludarabine and cyclophosphamide, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. CAR T-cell therapy is a type of treatment in which a patient's T cells (a type of immune system cell) are changed in the laboratory so they will attack cancer cells. T cells are taken from a patient's blood. Then the gene for a special receptor that binds to a certain protein on the patient's cancer cells is added to the T cells in the laboratory. The special receptor is called a chimeric antigen receptor. Large numbers of the CAR T cells are grown in the laboratory and given to the patient by infusion for treatment of certain cancers. Giving mosunetuzumab and/or polatuzumab vedotin after chemotherapy and CAR T-cell therapy may be more effective at controlling or shrinking the cancer than not giving them.
Conditions
- Diffuse Large B-Cell Lymphoma
 - Grade 3b Follicular Lymphoma
 - Primary Mediastinal (Thymic) Large B-Cell Lymphoma
 - Recurrent Diffuse Large B-Cell Lymphoma
 - Refractory Diffuse Large B-Cell Lymphoma
 - Transformed Follic Lymph to Diff Large B-Cell Lymphoma
 - Transformed Marg Zone Lymph to Diff Large B-Cell Lymphoma
 
Eligibility
- Eligible Ages
 - Over 18 Years
 - Eligible Sex
 - All
 - Accepts Healthy Volunteers
 - No
 
Criteria
Inclusion Criteria:
  -  STEP 1: REGISTRATION: Participants must have a histologically confirmed diagnosis of
     diffuse large B-cell lymphoma or follicular lymphoma grade 3b or primary mediastinal
     large B-cell lymphoma (PMBCL)
  -  STEP 1: REGISTRATION: Participants with transformed DLBCL must have transformed
     DLBCL from follicular or marginal zone lymphoma
  -  STEP 1: REGISTRATION: Participant must have bi-dimensionally measurable systemic
     disease (at least one lesion with longest diameter > 1.5 cm)
  -  STEP 1: REGISTRATION: Participants with secondary central nervous system (CNS)
     lymphoma (parenchymal, spinal cord, meningeal, cerebrospinal fluid involvement) must
     be asymptomatic from their CNS disease
  -  STEP 1: REGISTRATION: Participants must be registered for step 1 after they have
     signed institutional consent for CAR T-cell leukapheresis but prior to the start of
     lymphodepleting (LD) chemotherapy for commercial CAR T-cell product
  -  STEP 1: REGISTRATION: In the opinion of the enrolling physician, participants must
     be felt to be a candidate for CAR T-cell therapy with plans to be treated with Food
     and Drug Administration (FDA) approved commercially available CD19 CAR T-cell
     construct.
       -  Participants must qualify for commercially approved CD19 CAR T-cell therapy per
          FDA package insert.
       -  If the CAR T-cell product does not meet parameters to be given as an FDA
          approved product (i.e. does not meet specification criteria mandated by FDA and
          is infused under an expanded access protocol [EAP] or single participant
          investigational new drug [IND]) the participant will be taken off of study and
          no longer be eligible for step 2 randomization
  -  STEP 1: REGISTRATION: Participants are permitted to receive or have received
     'bridging therapy' after CAR T-cell leukapheresis. However, participants must not
     receive polatuzumab vedotin, and/or mosunetuzumab as part of bridging therapy.
       -  Bridging therapy is defined as lymphoma directed therapy administered between
          leukapheresis and the start of LD chemotherapy. This includes cytotoxic
          chemotherapy (e.g.: bendamustine and rituximab [BR], rituximab, gemcitabine and
          oxaliplatin [R-gem/ox]), radiation, corticosteroids, as well as novel therapies
          such as BTK inhibitors (e.g.: Ibrutinib), immunomodulators (e.g.:
          lenalidomide), monoclonal antibodies (e.g.: rituximab, obinutuzumab,
          tafasitamab) antibody drug conjugates (e.g: loncastuximab), checkpoint
          inhibitors (e.g.: pembrolizumab, nivolumab), clinical trial treatments, etc.
       -  If a participant receives polatuzumab vedotin or mosunetuzumab as bridging they
          will ineligible to continue on step 1 registration portion of the study and be
          ineligible for step 2 randomization
  -  STEP 1: REGISTRATION: PET-CT scan must be planned for completion within 60 days
     prior to the start of LD chemotherapy.
       -  All pre-CAR T-cell therapy disease must be assessed and documented on the
          baseline/pre-registration tumor assessment form.
       -  If receiving bridging therapy, participants must have a PET-CT scan upon
          completion of all planned bridging therapy. If the PET-CT scan after completion
          of bridging therapy is consistent with complete remission per Lugano criteria
          as determined by enrolling physician, that participant will be ineligible for
          step 2 randomization.
       -  Participants are permitted to receive corticosteroids after leukapheresis
          without the need to repeat a PET-CT scan. If steroids are used, they must be
          planned to stop no later than 3 days before CAR -T cell infusion.
       -  If response assessment by central review cannot be completed (I.e., poor
          quality of PET-CT scan, PET-CT performed out of window, etc.) this would be
          recorded as 'inadequate assessment' and patient would not be eligible for
          randomization
  -  STEP 1: REGISTRATION: Participants that have previously been treated with
     polatuzumab vedotin or mosunetuzumab prior to CAR T-cell leukapheresis for either
     indolent or aggressive NHL are eligible as long as the participant did not have
     refractory disease or progression/relapse within 6 months of the last infusion with
     either agent
  -  STEP 1: REGISTRATION: Participants must be planning to receive CAR T-cell infusion
     no earlier than 2 days and no later than 14 days after completion of the last day of
     lymphodepleting chemotherapy. Any participant receiving CAR T-cell infusion outside
     of this window will be ineligible for step 2 randomization
  -  STEP 1: REGISTRATION: LD chemotherapy prior to CAR T-cell infusion must be planned
     to start within 60 days after step 1 registration
  -  STEP 1: REGISTRATION: Participants must be >= 18 years of age at the time of
     registration
  -  STEP 1: REGISTRATION: Participants must have Zubrod performance score (PS) of 0, 1,
     or 2
  -  STEP 1: REGISTRATION: Total bilirubin =< 2 x institutional upper limit of normal
     (ULN) (within 14 days prior to registration)
       -  Unless due to Gilbert's disease or lymphomatous involvement of liver
  -  STEP 1: REGISTRATION: Aspartate aminotransferase (AST) and alanine aminotransferase
     (ALT) =< 3 x institutional ULN (within 14 days prior to registration)
  -  STEP 1: REGISTRATION: Creatinine clearance >= 40 mL/min, as estimated by the
     Cockcroft and Gault formula. The creatinine value used in the calculation must have
     been obtained within 14 days prior to registration. Estimated creatinine clearance
     is based on actual body weight
  -  STEP 1: REGISTRATION: Participants must have an echocardiogram (ECHO) or multigated
     acquisition scan (MUGA) within 60 days prior to registration with a cardiac ejection
     fraction >= 40%.
       -  Participants with current symptoms of cardiac disease must have a clinical risk
          assessment of cardiac function using the New York Heart Association Functional
          Classification. To be eligible for this trial, participants must be class 2B or
          better.
       -  Participants must not have documented myocardial infarction and percutaneous
          coronary intervention (PCI) within 6 months prior to registration or myocardial
          infarction without PCI within 3 months of registration, or unstable angina
  -  STEP 1: REGISTRATION: Participants with peripheral neuropathy must have < grade 2
  -  STEP 1: REGISTRATION: Participants with hepatitis B virus infection must have
     undetectable viral load within 14 days prior to registration, be on suppressive
     therapy and have no evidence of hepatitis B virus (HBV) related hepatic damage
  -  STEP 1: REGISTRATION: Participants with hepatitis C infection must have eradication
     therapy completed, have no evidence of hepatitis C infection (HCV) related damage
     and have undetectable viral load within 14 days prior to registration
  -  STEP 1: REGISTRATION: Participants with known human immunodeficiency virus
     (HIV)-infection must be on effective anti-retroviral therapy at time of registration
     and have undetectable viral load test on the most recent test results obtained
     within 6 months prior to registration
  -  STEP 1: REGISTRATION: Participants must be offered the opportunity to participate in
     banking for planned translational medicine and future research. With participant
     consent, any residuals from the mandatory tissue submission will also be banked for
     future research.
       -  Note: Streck tubes must be ordered in advance. Please allow 5-7 days for
          shipment of the collection kits
  -  STEP 1: REGISTRATION: NOTE: As a part of the OPEN registration process the treating
     institution's identity is provided in order to ensure that the current (within 365
     days) date of institutional review board approval for this study has been entered in
     the system.
       -  Participants must be informed of the investigational nature of this study and
          must sign and give informed consent in accordance with institutional and
          federal guidelines.
            -  For participants with impaired decision-making capabilities, legally
               authorized representatives may sign and give informed consent on behalf of
               study participants in accordance with applicable federal, local, and
               Central Institutional Review Board (CIRB) regulations
  -  STEP 2: RANDOMIZATION: Participants must have met all eligibility criteria for step
     1 registration
  -  STEP 2: RANDOMIZATION: Participant's CAR T-cell product must have met specification
     parameters to be given as an FDA approved commercial product
  -  STEP 2: RANDOMIZATION: Participants must have a PET-CT scan between days 25-40 after
     CAR T-cell infusion and determined to have a response consistent with stable disease
     or partial remission by central review compared to most recent pre-LD chemo/CAR
     T-cell PET-CT scan.
       -  Note: Patients with delayed enrollment > 21 days after 'day +30' PET-CT scan
          will necessitate a repeat PET-CT scan if concerning signs or symptoms of
          lymphoma progression develop.
       -  Note: If response assessment by central review cannot be completed (I.e., poor
          quality of PET-CT scan, PET-CT performed out of window, etc.) this would be
          recorded as 'inadequate assessment' and patient would not be eligible for
          randomization
  -  STEP 2: RANDOMIZATION: Eligible participants must be randomized no later than 60
     days after CAR -T infusion
  -  STEP 2: RANDOMIZATION: Participants must have started LD chemotherapy within 60 days
     of signing consent for step 1 registration
  -  STEP 2: RANDOMIZATION: Participants must have S2114 CAR T-cell therapy form
     submitted to Southwest Oncology Group (SWOG) prior to step 2 randomization
  -  STEP 2: RANDOMIZATION: Participants must have had a PET-CT scan upon completion of
     all planned bridging therapy if received, with the exception of up to 7 days of
     corticosteroids. If the PET-CT scan after completion of bridging therapy was
     consistent with complete remission per Lugano criteria as determined by enrolling
     physician, that participant will be ineligible for step 2 randomization.
       -  If response assessment by central review cannot be completed (I.e., poor
          quality of PET-CT scan, PET-CT performed out of window, etc.) this would be
          recorded as 'inadequate assessment' and patient would not be eligible for
          randomization
  -  STEP 2: RANDOMIZATION: Participants must have Zubrod PS of 0, 1, or 2
  -  STEP 2: RANDOMIZATION: Absolute neutrophil count (ANC) >= 1.0 x 10^3/uL and
     participants must not have received myeloid growth factor within 72 hours prior to
     this lab being drawn (within 7 days prior to step 2 randomization)
  -  STEP 2: RANDOMIZATION: Platelets >= 75 x 10^3/uL and participants must not have
     received platelet transfusion within 72 hours prior to this lab being drawn (within
     7 days prior to step 2 randomization)
  -  STEP 2: RANDOMIZATION: Total bilirubin =< 2 x institutional ULN (within 7 days prior
     to step 2 randomization)
       -  Unless due to Gilbert's disease or lymphomatous involvement of liver
  -  STEP 2: RANDOMIZATION: AST and ALT =< 3 x institutional ULN (within 7 days prior to
     step 2 randomization)
  -  STEP 2: RANDOMIZATION: Creatinine clearance >= 40 mL/min, as estimated by the
     Cockcroft and Gault formula. The creatinine value used in the calculation must have
     been obtained within 7 days prior to step 2 randomization. Estimated creatinine
     clearance is based on actual body weight (within 7 days prior to step 2
     randomization)
  -  STEP 2: RANDOMIZATION: Participants with peripheral neuropathy must have < grade 2
  -  STEP 2: RANDOMIZATION: Participants with current symptoms of cardiac disease must
     have a clinical risk assessment of cardiac function using the New York Heart
     Association Functional Classification. To be eligible for this trial, participants
     must be class 2B or better
  -  STEP 2: RANDOMIZATION: Participants with history of hepatitis B viral infection must
     have undetectable viral load within 14 days prior to step 2 randomization and on
     suppressive therapy
  -  STEP 2: RANDOMIZATION: Participants with history of hepatitis C viral infection must
     have undetectable viral load within 14 days prior to step 2 randomization
  -  STEP 2: RANDOMIZATION: Participants with known human immunodeficiency virus
     (HIV)-infection must be continuing to receive anti-retroviral therapy and have an
     undetectable viral load test within 14 days prior to step 2 randomization
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants must have documented
     disease progression while on Arm 4 (observation) on this protocol. The follow-up
     tumor assessment form documenting disease progression must be submitted to SWOG
     prior to step 3 crossover registration
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants must be registered within
     28 days of the date of progression
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants must have imaging that
     clearly demonstrates progression compared to day +30 PET-CT scan
       -  Note: These scans should be performed as standard of care and only performed
          between scheduled response assessments required for study if symptoms arise
          that are concerning for progression
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants must have Zubrod PS of 0,
     1, or 2
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): ANC >= 1.0 x 10^3/uL and participants
     must not have received myeloid growth factor within 72 hours prior to this lab being
     drawn (within 14 days prior to step 3 crossover registration)
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Platelets >= 75 x 10^3/uL and
     participants must not have received platelet transfusion within 72 hours prior to
     this lab being drawn (within 14 days prior to step 3 crossover registration)
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Total bilirubin =< 2 x institutional
     ULN (within 14 days prior to step 3 crossover registration)
       -  Unless due to Gilbert's disease or lymphomatous involvement of liver
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): AST and ALT =< 3 x institutional ULN
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Creatinine clearance >= 40 mL/min, as
     estimated by the Cockcroft and Gault formula. The creatinine value used in the
     calculation must have been obtained within days prior to step 3 crossover
     registration. Estimated creatinine clearance is based on actual body weight (within
     14 days prior to step 3 crossover registration)
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants with peripheral neuropathy
     must have < grade 2
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants with current symptoms of
     cardiac disease must have a clinical risk assessment of cardiac function using the
     New York Heart Association Functional Classification. To be eligible for this trial,
     participants must be class 2B or better
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants with history of hepatitis
     B viral infection must have undetectable viral load within 14 days prior to step 3
     crossover registration and on suppressive therapy
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants with history of hepatitis
     C viral infection must have undetectable viral load within 14 days prior to step 3
     crossover registration
  -  STEP 3: CROSSOVER REGISTRATION (ARM 4 ONLY): Participants with known human
     immunodefici
Study Design
- Phase
 - Phase 2
 - Study Type
 - Interventional
 - Allocation
 - Randomized
 - Intervention Model
 - Parallel Assignment
 - Primary Purpose
 - Treatment
 - Masking
 - None (Open Label)
 
Arm Groups
| Arm | Description | Assigned Intervention | 
|---|---|---|
| 
                        Experimental Step I (lymphodepleting chemotherapy)  | 
                    Patients receive lymphodepleting chemotherapy consisting of fludarabine IV and cyclophosphamide IV on study. Patients then receive tisagenlecleucel IV, axicabtagene ciloleucel IV, or lisocabtagene maraleucel IV on study. | 
                                                
  | 
                
| 
                        Experimental Step II Arm I (mosunetuzumab)  | 
                    Patients receive mosunetuzumab IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. | 
                                                
  | 
                
| 
                        Experimental Step II Arm II (polatuzumab vedotin)  | 
                    Patients receive polatuzumab vedotin IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. | 
                                                
  | 
                
| 
                        Experimental Step II Arm III (polatuzumab vedotin, mosunetuzumab)  | 
                    Patients receive polatuzumab vedotin IV and mosunetuzumab IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. | 
                                                
  | 
                
| 
                        Active Comparator Step II Arm IV (observation)  | 
                    Patients undergo observation on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. Patients with subsequent progression within 12 months of CAR T-cell therapy may crossover to Arm III. | 
                                                
  | 
                
Recruiting Locations
Tucson 5318313, Arizona 5551752 85719
Tucson 5318313, Arizona 5551752 85719
Fayetteville 4110486, Arkansas 4099753 72703
Little Rock 4119403, Arkansas 4099753 72205
Site Public Contact
501-686-8274
Rogers 4128894, Arkansas 4099753 72758
Springdale 4132093, Arkansas 4099753 72762
Irvine 5359777, California 5332921 92612
Orange 5379513, California 5332921 92868
San Francisco 5391959, California 5332921 94143
Site Public Contact
877-827-3222
Gainesville 4156404, Florida 4155751 32610
Atlanta 4180439, Georgia 4197000 30322
Site Public Contact
404-778-1868
Atlanta 4180439, Georgia 4197000 30342
Site Public Contact
404-851-7115
Boise 5586437, Idaho 5596512 83712
Fruitland 5593708, Idaho 5596512 83619
Meridian 5600685, Idaho 5596512 83642
Nampa 5601933, Idaho 5596512 83687
Twin Falls 5610810, Idaho 5596512 83301
Chicago 4887398, Illinois 4896861 60612
Site Public Contact
312-355-3046
Chicago 4887398, Illinois 4896861 60637
Maywood 4901514, Illinois 4896861 60153
Site Public Contact
708-226-4357
Iowa City 4862034, Iowa 4862182 52242
Site Public Contact
800-237-1225
Kansas City 4273837, Kansas 4273857 66160
Overland Park 4276873, Kansas 4273857 66210
Westwood 4281639, Kansas 4273857 66205
Louisville 4299276, Kentucky 6254925 40202
Site Public Contact
502-562-3429
Louisville 4299276, Kentucky 6254925 40245
Baltimore 4347778, Maryland 4361885 21287
Battle Creek 4985153, Michigan 5001836 49017
Detroit 4990729, Michigan 5001836 48201
Farmington Hills 4992523, Michigan 5001836 48334
Grand Rapids 4994358, Michigan 5001836 49503
Grand Rapids 4994358, Michigan 5001836 49503
Kalamazoo 4997787, Michigan 5001836 49007
Kalamazoo 4997787, Michigan 5001836 49007
Kalamazoo 4997787, Michigan 5001836 49009
Muskegon 5003132, Michigan 5001836 49444
Niles 5003514, Michigan 5001836 49120
Site Public Contact
616-391-1230
Norton Shores 5004005, Michigan 5001836 49444
Reed City 5006946, Michigan 5001836 49677
Saint Joseph 5008327, Michigan 5001836 49085
Traverse City 5012495, Michigan 5001836 49684
Wyoming 5015618, Michigan 5001836 49519
Albuquerque 5454711, New Mexico 5481136 87106
New York 5128581, New York 5128638 10032
New York 5128581, New York 5128638 10065
Site Public Contact
212-746-1848
Rochester 5134086, New York 5128638 14642
Site Public Contact
585-275-5830
Webster 5143495, New York 5128638 14580
Charlotte 4460243, North Carolina 4482348 28203
Site Public Contact
800-804-9376
Durham 4464368, North Carolina 4482348 27710
Site Public Contact
888-275-3853
Winston-Salem 4499612, North Carolina 4482348 27157
Site Public Contact
336-713-6771
Cleveland 5150529, Ohio 5165418 44106
Oklahoma City 4544349, Oklahoma 4544379 73104
Newberg 5742726, Oregon 5744337 97132
Oregon City 5744253, Oregon 5744337 97045
Portland 5746545, Oregon 5744337 97213
Portland 5746545, Oregon 5744337 97225
Portland 5746545, Oregon 5744337 97239
Danville 5186327, Pennsylvania 6254927 17822
Philadelphia 4560349, Pennsylvania 6254927 19104
Wilkes-Barre 5219488, Pennsylvania 6254927 18711
Boiling Springs 4571805, South Carolina 4597040 29316
Site Public Contact
864-241-6251
Charleston 4574324, South Carolina 4597040 29425
Easley 4577263, South Carolina 4597040 29640
Greenville 4580543, South Carolina 4597040 29605
Site Public Contact
864-241-6251
Greenville 4580543, South Carolina 4597040 29605
Site Public Contact
864-241-6251
Greenville 4580543, South Carolina 4597040 29615
Site Public Contact
864-241-6251
Greer 4580599, South Carolina 4597040 29650
Site Public Contact
864-241-6251
Seneca 4595346, South Carolina 4597040 29672
Site Public Contact
864-241-6251
Memphis 4641239, Tennessee 4662168 38120
Burlington 5234372, Vermont 5242283 05401
Richmond 4781708, Virginia 6254928 23298
Madison 5261457, Wisconsin 5279468 53718
Madison 5261457, Wisconsin 5279468 53792
Milwaukee 5263045, Wisconsin 5279468 53226
Site Public Contact
414-805-3666
New Berlin 5264381, Wisconsin 5279468 53151
Site Public Contact
414-805-0505
More Details
- NCT ID
 - NCT05633615
 - Status
 - Recruiting
 - Sponsor
 - SWOG Cancer Research Network
 
Detailed Description
PRIMARY OBJECTIVES: I. To compare the progression-free survival in participants with relapsed/refractory large B-cell lymphoma or follicular lymphoma grade 3B with stable disease (SD) or partial remission (PR) on first imaging response by central review (day +30 positron emission tomography [PET]/computed tomography [CT] scan) after commercial CD19 CAR T-cell therapy who are randomized to receive each consolidation therapy versus those that receive no consolidation therapy (i.e. control). Ia. Specifically, to compare the progression free survival (PFS) of 1) mosunetuzumab consolidation to no consolidation, 2) polatuzumab vedotin consolidation to no consolidation, 3) mosunetuzumab + polatuzumab vedotin to no consolidation. SECONDARY OBJECTIVES: I. To compare overall survival (OS) in participants randomized to each consolidation treatment arm versus control. II. To compare the complete remission (CR) conversion rate up to one year in participants randomized to each consolidation arm versus control. III. To evaluate the treatment-related adverse events in participants randomized to each consolidation arm. IV. To evaluate the association between total metabolic tumor volume (TMTV), standardized uptake value (SUV) max, and sum product (SPD) of diameters by PET-CT at first imaging response with complete remission conversion up to one year in participants randomized to each consolidation arm as well as those randomized to control. V. To evaluate the overall response rate (ORR), CR rate, PFS, and OS of participants randomized to Arm 4 (observation) who have lymphoma progression within 12 months of CAR T-cell infusion and subsequently 'cross-over' to receive treatment with mosunetuzumab + polatuzumab vedotin. VI. To estimate overall survival for all patients registered to this study. VII. To assess the difference in overall survival between participants who achieved CR at first imaging (day +30) versus those who did not achieve CR at first imaging. BANKING OBJECTIVES: I. To bank specimens for future correlative studies. II. To bank PET-CT images for future correlative studies. OUTLINE: STEP I: Patients receive lymphodepleting chemotherapy consisting of fludarabine intravenously (IV) and cyclophosphamide IV on study. Patients then receive tisagenlecleucel IV, axicabtagene ciloleucel IV, or lisocabtagene maraleucel IV on study. STEP II: Patients are randomized to 1 of 4 arms. ARM I: Patients receive mosunetuzumab IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. ARM II: Patients receive polatuzumab vedotin IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. ARM III: Patients receive polatuzumab vedotin IV and mosunetuzumab IV on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. ARM IV: Patients undergo observation on study. Patients also undergo PET-CT and/or CT and undergo collection of blood and tissue samples throughout the study. Patients with subsequent progression within 12 months of CAR T-cell therapy may crossover to Arm III.