Tactiva Therapeutics Reports Data Highlighting a Novel Dual CD4/CD8 T Cell Receptor with Potential for Use Against a Broad Range of Cancers

Washington, DC, April 05, 2017 --(PR.com)-- Tactiva Therapeutics today reported on its unique, dual enhanced adoptive cell therapy (DEACT) platform, incorporating its proprietary, engineered CD4/CD8 T cell receptors (TCR) with potential broad utility in cancer immunotherapy, including melanoma and ovarian cancer. A late breaking abstract describing these findings was presented as part of the Annual Meeting of the American Association of Cancer Research (AACR), April 1-5, 2017 in Washington, D.C.

"Discovery of a unique T cell receptor from CD4 cells that directly recognizes the prototypic tumor-associated antigen, NY-ESO-1, on cancer cells provided the basis for development of novel TCR-engineered CD4 cells to promote durable anti-tumor activity,” said Richard Koya, M.D., PhD. Associate Professor of Oncology, Roswell Park Cancer Institute. “These CD4-TCRs are incorporated into hematopoietic stem cells and, by homing in the bone marrow, may orchestrate a more complete and durable antitumor immune response, since they can transform into T cells that can recognize tumor cells and help the cytolytic CD8 T cells.”

Tactiva’s approach to cancer immunotherapy combines their unique DEACT platform and propriety CD4/CD8 TCR assets with tumor overexpression of NY-ESO-1 to ensure uniform tumor cell death.

“This study provides a signal of the potency and durability of our proprietary CD4-TCR-engineered stem cells,” said Matt Colpoys, Tactiva CEO. “The synergistic and efficient tumor burden control seen in vivo was impressive and warrants further exploration in clinical trials."

Abstract Highlights
In an abstract by Koya et al at Roswell Park Cancer Institute in Buffalo, NY, the researchers confirmed human hematopoietic stem cells transduced with synthetic TCRs for NY-ESO-1 and injected into a new mouse transgenic model, differentiated and proliferated over 2-3 months into CD4-TCR cells. Furthermore, when groups of these mice were injected with human melanoma or ovarian tumors, remarkable tumor growth arrest (~5 to 6-fold magnitude) was observed after 32 days in the group also receiving CD8-TCR cells compared with groups receiving untransduced CD4 cells or controls (no CD4-TCR or CD8 cells).

According to Dr. Koya, "These engineered CD4-TCR cells may represent a new, specifically targeted therapy for multiple tumor types that create a durable in vivo supply of fully active CD4-TCR cells with anti-tumor activity and may help CD8 cells with sustained tumor suppression.”

About Tactiva
Tactiva is a development stage immuno-oncology company with a unique approach to adoptive T-cell therapy. More information about the company, its technology, and products can be found on its web site at www.tactivatherapeutics.com
AXON Communications
Marian Cutler