Manufactured leukemia-specific T cells may help increase survival rates

Infusion of a novel, multi-targeted donor-derived T-cell therapy is safe and well-tolerated in patients with high-risk or relapsed leukemia after a donated bone marrow transplant, according to a new study published in Blood Advances. The findings suggest that this strategy may make a difference in these patients, as will be evaluated in later phase trials.

“A tumor cell is very clever because it tries to hide from T-cell therapies by deleting or down regulating targets that the T cell is directed towards,” said Catherine Bollard, M.D., M.B.Ch.B., director of the Center for Cancer and Immunology Research at Children’s National Hospital and co-senior author. “This novel cell therapy has the potential to get around that escape by targeting multiple proteins in a single product, making it much harder for the cancer cell to hide from the immune attack by the T cells.”

The tumor-associated antigen-specific T cell (TAA-T) product targets WT1, survivin and PRAME, which are proteins that play a role in cancer cell proliferation and survival. They are overexpressed in leukemia and many other human malignancies. The researchers chose to expand the T cells to target many malignancies through at least one expressed antigen. The manufactured TAA-T products are derived from peripheral blood mononuclear cells (PBMCs) obtained from the patient’s own BMT donor.

The hold-up in the field

Conventional therapies for patients with high-risk or relapsed malignancies often fail due to toxicity associated with additional chemotherapy and second transplant, particularly in those who relapse early after transplant. This novel cellular immunotherapy approach is shown to be safe and targets antigens that are found in CD19 positive and negative blood cancers, which may broaden the applicability to other cancer types, such as acute myeloid leukemia, that are currently lacking effective T cell therapy options.

What’s next

“Evaluation and tracking of unique T cell receptor clonotypes in patients following TAA-T cell infusion demonstrated expansion and persistence of some clonotypes up to 6 months to one-year post-infusion,” said Hannah Kinoshita, M.D., oncology fellow at Children’s National and co-lead author. “In future studies, we are hoping to identify and track unique target antigen-specific clonotypes from the T cell product infused to better understand the immunobiological effect of the infused T cells and how that can be translated into improved clinical outcomes.”

Children’s National Hospital leads the way

The Cell Enhancement and Technologies for Immunotherapy (CETI) program at Children’s National specializes in developing and analyzing novel cellular therapeutics such as this one.

You can read the full study “Outcome of Donor-derived TAA-T cell therapy in Patients with High-risk or Relapsed Acute Leukemia Post Allogeneic BMT,” in Blood Advances. Children’s National researchers worked in partnership with Rick Jones, M.D., co-senior author and Kenneth Cooke, M.D., Ph.D., co-lead author, both at Johns Hopkins Medicine.