Inclusion Criteria:

          1. Histologically confirmed, aggressive B-cell NHL at relapse/progression or PR after
             front line therapy. Aggressive B-cell NHL is heretofore defined by the following list
             of subtypes (Swerdlow et al 2016):

               1. DLBCL, NOS,

               2. FL grade 3B,

               3. Primary mediastinal large B cell lymphoma (PMBCL),

               4. T cell rich/histiocyte rich large B cell lymphoma (T/HRBCL),

               5. DLBCL associated with chronic inflammation,

               6. Intravascular large B-cell lymphoma,

               7. ALK+ large B-cell lymphoma,

               8. B-cell lymphoma, unclassifiable, (with features intermediate between DLBCL and
                  classical Hodgkin's Lymphoma (HL)),

               9. High grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements,

              10. High-grade B-cell lymphoma, NOS

              11. HHV8+ DLBCL, NOS

              12. DLBCL transforming from follicular lymphoma

              13. DLBCL transforming from marginal zone lymphoma

              14. DLBCL, leg type

          2. Relapse or progression within 365 days from last dose of anti CD20 antibody and
             anthracycline containing first line immunochemotherapy or refractory (have not
             achieved a CR).

          3. Patient is considered eligible for autologous HSCT as per local investigator
             assessment. Note: Intention to transplant and type of high dose chemotherapy (HDCT)
             regimen will be documented at the time of study entry

          4. Disease that is both active on PET scan (defined as 5-Deauville scorepoint-scale of 4
             or 5) and measurable on CT scan, defined as::

               1. Nodal lesions >15 mm in the long axis, regardless of the length of the short
                  axis, and/or

               2. Extranodal lesions (outside lymph node or nodal mass, but including liver and
                  spleen) >10 mm in long AND short axis

          5. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

          6. Adequate organ function:

             Renal function defined as:

               1. Serum creatinine of ≤1.5 x upper limit of normal (ULN), OR estimated glomerular
                  filtration rate (eGFR) ≥ 60 mL/min/1.73 m2

                  Hepatic function defined as:

               2. Alanine Transaminase (ALT) and Aspartate Transiminase (AST) ≤ 5 × ULN

               3. Total bilirubin ≤ 1.5 x ULN with the exception of patients with Gilbert syndrome
                  who may be included if their total bilirubin is ≤3.0 × ULN and direct bilirubin
                  ≤1.5 × ULN

                  Hematologic Function (regardless of transfusions) defined as:

               4. Absolute neutrophil count (ANC) >1000/mm3

               5. Absolute lymphocyte count (ALC) >300/mm3 OR Absolute number of CD3+ T cells
                  >150/mm3 (only for patients with non-historical apheresis)

               6. Platelets ≥50000/mm3

               7. Hemoglobin >8.0 g/dl

                  Adequate pulmonary function defined as:

               8. No or mild dyspnea (≤ Grade 1)

               9. Oxygen saturation measured by pulse oximetry > 90% on room air

              10. Forced expiratory volume in 1 s (FEV1) ≥ 50% and/or carbon monoxide diffusion
                  test (DLCO) ≥50% of predicted level

          7. Must have a leukapheresis material of non-mobilized cells available for manufacturing.

        Exclusion Criteria:

          1. Prior treatment with anti-CD19 therapy, T cell therapy, or any prior gene therapy
             product

          2. Treatment with any systemic lymphoma-directed second line anticancer therapy prior to
             randomization. Only steroids and local irradiation are permitted for disease control

          3. Patients with active central nervous system (CNS) involvement by disease under study
             are excluded, except if the CNS involvement has been effectively treated and local
             treatment was >4 weeks before randomization

          4. Prior allogeneic HSCT

          5. Clinically significant active infection

          6. Any of the following cardiovascular conditions:

               -  Unstable angina, myocardial infarction, coronary artery bypass graft (CABG), or
                  stroke within 6 months prior to screening,

               -  Left ventricle ejection fraction (LVEF) <45% as determined by echocardiogram
                  (ECHO) or magnetic resonance angiography (MRA) or multigated acquisition (MUGA)
                  at the screening assessment.

               -  New York Heart Association (NYHA) functional class III or IV (Chavey et al 2001),
                  within the past 12 months.

               -  Clinically significant cardiac arrhythmias (e.g., ventricular tachycardia),
                  complete left bundle branch block, high-grade atrioventricular (AV) block (e.g.,
                  bifascicular block, Mobitz type II) and third degree AV block unless adequately
                  controlled by pacemaker implantation.

               -  Resting QTcF ≥450 msec (male) or ≥460 msec (female) at screening or inability to
                  determine the QTcF interval

               -  Risk factors for Torsades de Pointes (TdP), including uncorrected hypokalemia or
                  hypomagnesemia, history of cardiac failure, or history of clinically significant/
                  symptomatic bradycardia, or any of the following:

               -  Long QT syndrome, family history of idiopathic sudden death or congenital long QT
                  syndrome

               -  Concomitant medication(s) with a "Known Risk of Torsades de Pointes" per
                  crediblemeds.org that cannot be discontinued or replaced by safe alternative
                  medication.

          7. Patients with active neurological autoimmune or inflammatory disorders (e.g.,
             Guillain-Barré Syndrome (GBS), Amyotrophic Lateral Sclerosis (ALS)) and clinically
             significant active cerebrovascular disorders (e.g. cerebral edema, posterior
             reversible encephalopathy syndrome (PRES))

        Other protocol-defined inclusion and exclusion criteria may apply.