Immunotherapy in Lymphoid Malignancies


ENGINEERED T CELL EXPRESSING CHIMERIC ANTIGEN RECEPTOR AGAINST CD19 ON LYMPHOID MALIGNANCIES

Assistant Professor Usanarat Anurathapan, MD

Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand


SYNOPSIS

Cancer is one of the leading causes of death worldwide. In Thailand, the incidence of childhood malignant diseases was 74.9 cases per million. Leukemia and lymphoma were the most common cancer in Thai children. Acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma expressing a distinct antigen, CD19, are called B-cell lymphoid malignancies. More than a half of pediatric patients with those diseases were cured and survived after standard treatments, including chemotherapy and/or radiotherapy. Some of those patients have been successfully treated with hematopoietic stem cell transplantation, either from allogeneic or autologous donors. However, small number of patients, especially with relapsed or refractory B-cell lymphoid malignant diseases, could not cured by any available standard treatments. Cellular immunotherapy is a promising novel therapy for those patients. Interestingly, Chimeric antigen receptor (CAR)-modified T lymphocyte has been recently FDA-approved for the treatment of ALL in children and diffuse large B-cell lymphoma (DLBCL) in adult. We would like to establish the treatment for children with ALL using CAR-modified T lymphocyte (CAR-T cell) against CD19-expressing leukemic cells. 

We successfully generated a second generation of CAR-CD19 lentivirus, comprised of endodomains of CD28 and CD3ζ as a co-stimulatory and a signalling domain, respectively. Furthermore, we use a CH3 portion of an IgG2 as a hinge part to extend an antigen detection part, ScFV against CD19, out of the surface of the engineered T lymphocyte. We assessed the expression of CAR-CD19 molecule in the modified T cells using Q-PCR; the transduction efficiency was averagely 41%. We co-cultured our engineered T lymphocytes with CD19-expressing cancer cell lines, Raji, RS4 and Sup-B15, which were specifically killed of 35-50%. Moreover, our modified T cells were expressed high levels of interferon-gamma after co-cultured with those CD19-positive cell lines. We have recently developed a phase1/2 clinical trial using our CAR-T cells in ALL pediatric patients who receive stem cell transplantation from related donors. The CAR-CD19 T cells, generated from the designated donors, have been produced in a GMP-compliant facility. Furthermore, those engineered T lymphocytes have been evaluated according to the protocol, especially a release criteria including viability, transduction efficiency, cytotoxicity and sterility, prior to administered to the volunteers. Thus far, we generated the CAR-CD19 T cells for 6 enrolled volunteers, however we infused one patient with a very low dose of our modified T lymphocyte. We have not found any adverse reactions related to the CAR-CD19 T cell infusion in that patient. 

In summary, we have generated a novel treatment for children with ALL using CAR-CD19 T cells. We are exploring the safety and feasibility of this cellular immunotherapy in Thailand.

Event Hours(1)

  • Lotus 1-2.

    01:00 pm – 02:30 pm

    Speakers:
    1. Dr. Archrob Khuhapinant (SI)
    2. Asst. Prof. Udomsak Bunworasate (CU)
    3. Asst. Prof. Usanarat Anurathapan (Rama)

    Moderator:
    Prof. Suradej Hongeng (Rama)