Inclusion Criteria:

          1. Participant must have relapsed or refractory CD19+ disease as defined by one of the
             following:

             a. Relapsed or refractory acute lymphoblastic leukemia as defined by one of the
             following: i. Second or greater relapse ii. Any relapse after allogeneic stem cell
             transplantation (SCT) iii. Chemorefractory as defined by not achieving CR after 2
             cycles of a standard induction chemotherapy or one cycle of salvage therapy b.
             Histologically confirmed B-cell non-Hodgkin's lymphoma including diffuse large B-cell
             lymphoma (DLBCL) not otherwise specified, primary mediastinal large B-cell lymphoma,
             or transformed follicular lymphoma with one of the following: i. Second or greater
             relapse ii. Any relapse after autologous or allogeneic SCT iii. Chemorefractory as
             defined by not achieving CR after 2 cycles of a standard chemotherapy or one cycle of
             salvage therapy

          2. All eligible participants must have documentation of CD19 tumour expression
             demonstrated in tissue biopsy, bone marrow or peripheral blood within the 3 months
             prior to study screening.

          3. Adequate organ function

          4. Participant age: 18 to 75 years.

          5. Provide written informed consent

        Exclusion Criteria:

        An individual who meets any of the following criteria will be excluded from participation
        in this study:

          1. Isolated extra-medullary disease.

          2. Participants with concomitant genetic syndrome, such as Fanconi anemia, Kostmann
             syndrome, Shwachman syndrome or any other known familial bone marrow failure syndrome.

          3. Prior malignancy, except carcinoma in situ of the skin or cervix treated with curative
             intent and with no evidence of active disease.

          4. Prior treatment with any gene therapy product.

          5. Participants with polymerase chain reaction (PCR) positive hepatitis B, hepatitis C,
             or Human Immunodeficiency Virus (tested within 8 weeks of screening), or any
             uncontrolled infection at screening.

          6. Presence of active Graft Versus Host Disease requiring systemic therapy.

          7. Participants who have undergone allogeneic SCT less than 6 months prior to CLIC-1901
             cell infusion or who have undergone donor lymphocyte infusion less than 6 weeks prior
             to CLIC-1901 cell infusion.

          8. Active Central Nervous System (CNS) involvement by malignancy, defined by CNS-3 per
             National Comprehensive Cancer Network guidelines.

          9. History of anaphylaxis to gentamicin or its derivatives.

         10. Participant has received an investigational agent within the 30 days prior to
             enrolment visit.

         11. Pregnant or nursing women.