Oncternal Therapeutics, Inc. (NASDAQ:ONCT), a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies, today announced the presentation of preclinical data from its ROR1 chimeric antigen receptor T cell (CAR-T) program at the American Society of Clinical Oncology (ASCO) – Society for Immunotherapy of Cancer (SITC) meeting in Orlando, Florida. A copy of the poster presentation is available online at www.oncternal.com.
In preclinical studies, anti-ROR1 CAR-T constructs were evaluated in an animal model of human leukemia. A single dose of anti-ROR1 CAR T-cells expanded in treated animals and the chimeric T cells trafficked to the disease sites. By week four, leukemia cells were cleared from major tissue reservoirs, including bone marrow, kidneys and spleen. CAR-T cell-treated animals survived longer than 90 days compared to 21 days for animals in control groups. The CAR-T cells were highly active and detected in mouse tissues more than two months after injection.
This research effort was led by Professor Thomas J. Kipps, M.D., Ph.D., and Charles Prussack, Pharm.D., Ph.D., at the University of California San Diego (UC San Diego) under a research grant from the California Institute of Regenerative Medicine (CIRM).
“It is exciting to see the potent preclinical activity of the ROR1 CAR-T cell therapy and its selectivity in targeting tumors,” said Thomas Kipps, M.D., Ph.D., Professor of Medicine, Evelyn and Edwin Tasch Chair in Cancer Research, and Deputy Director of Research Operations at the UC San Diego Moores Cancer Center. “This CAR-T cell product utilizes the ROR1 binding domain derived from cirmtuzumab (UC-961), a clinical stage antibody that is currently being evaluated in patients with hematological malignancies and solid tumors. The challenges of CAR-T therapies include patient relapses due to the loss of target antigen and safety issues due to targeting of normal cells expressing the antigen. Harnessing cirmtuzumab’s specificity for ROR1 expressed on cancer cells has the potential to improve CAR-T efficacy and safety, and address the high unmet medical need for treating patients with aggressive cancers.”
“We are encouraged by the preclinical results of this ROR1 CAR-T program and look forward to advancing it to clinical testing, initially for treating patients with hematological cancers, potentially in the fourth quarter of this year,” said James Breitmeyer, M.D., Ph.D., Oncternal’s President and CEO.