National Cancer Institute (NCI) Small Business Innovation Research (SBIR) award funds development of ET501 toward an Investigational New Drug application

ATLANTA, Oct. 15, 2026 /PRNewswire/ — Expression Therapeutics, Inc., a clinical-stage gene and cell therapy company, today announced that NCI SBIR within the National Institutes of Health (NIH) has awarded a Phase II grant of $2,058,885 to advance ET501, its investigational PTK7-targeted γδ (gamma delta) T-cell therapy, for children with high-risk neuroblastoma. Over two years, the award funds program activities intended to support an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA).

Neuroblastoma is a pediatric cancer of the sympathetic nervous system. U.S. physicians diagnose more than 650 cases each year, at a median age of 17 months. For children with high-risk disease, five-year event-free survival is 51.2% and five-year overall survival is 62.5%, according to a Children’s Oncology Group analysis of 4,832 patients enrolled from 2007 to 2017.

ET501 applies the company’s ADEPT-STAR platform, which uses the company’s LENTeT lentiviral delivery system to engineer γδ T cells that secrete a T-cell engager at the tumor site. γδ T cells recognize stressed and cancerous cells without requiring a tissue-type (HLA) match. ET501 is designed to secrete a PTK7×CD3 engager that binds PTK7 (protein tyrosine kinase 7), a protein on the surface of neuroblastoma cells, and CD3 on T cells, directing both the infused γδ T cells and T cells already in the tumor against cancer cells.

“Children with high-risk neuroblastoma need treatment options beyond today’s regimens,” said David Townson, Ph.D., Chief Executive Officer of Expression Therapeutics. “This award funds the work that stands between ET501 and an IND application. It also advances the second program on our γδ T-cell platform, ET401 for adults with neuroendocrine tumors.”

“ET501 is designed to have γδ T cells produce a PTK7-directed engager inside the tumor, where it can recruit the immune cells already present,” said Brian Petrich, Ph.D., Vice President of Research and Development at Expression Therapeutics and Contact Principal Investigator on the SBIR award. “This grant funds the studies that will show whether that design performs as intended and whether it supports an IND application.”

About ET501
ET501 is a preclinical, investigational γδ T-cell therapy candidate. It has not been tested in humans, and neither the FDA nor any other regulatory authority has approved it for any use.

About Expression Therapeutics
Expression Therapeutics, Inc. is a clinical-stage gene and cell therapy company based in Tucker, Georgia. Its lead program, ET3, is an autologous hematopoietic stem cell gene therapy for hemophilia A that has completed a Phase 1 trial and holds FDA Fast Track, Orphan Drug and Rare Pediatric Disease designations. The company also develops γδ T-cell therapies for neuroendocrine tumors (ET401) and pediatric neuroblastoma (ET501). Its technologies include the ADEPT-STAR γδ T-cell platform, the eCO expression cassette optimization platform and the LENTeT lentiviral delivery system. Expression Therapeutics operates a 43,000-square-foot cGMP cell and viral vector manufacturing facility in Cincinnati, Ohio. For more information, visit www.expressiontherapeutics.com.

NIH Funding Acknowledgment
Research reported in this press release was supported by the National Cancer Institute of the National Institutes of Health under Award Number R44CA281633. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Forward-Looking Statements
This press release contains forward-looking statements, including statements about the development of ET501 and ET401, the activities the NIH grant will fund, the preparation and submission of an IND application, and the potential of the company’s γδ T-cell platform. These statements reflect the company’s current expectations and involve risks and uncertainties that could cause actual results to differ materially. These risks include the possibility that preclinical studies of ET501 do not produce results that support an IND application; that PTK7 expression, safety or activity in patients differs from what preclinical studies observed; that the company cannot manufacture ET501 at the quality or scale that clinical trials require; that the FDA requires additional studies; that NIH reduces, delays or terminates grant funding; and that the company cannot obtain the additional capital its programs require. Expression Therapeutics undertakes no obligation to update these statements except as law requires.

Media and Investor Contact
Kimberly Nearing
Chief Business Officer
Expression Therapeutics, Inc.
1860 Montreal Road, Tucker, Georgia 30084
knearing@expressiontherapeutics.com
+1 (404) 369-0665

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SOURCE Expression Therapeutics, Inc.