SQZ Biotech to Present First Time Data Demonstrating Potential of Company’s Second Novel Cell Therapy Approach in Oncology – Activating Antigen Carriers (AACs)
Preclinical data demonstrate SQZ AACs ability to prime antigen-specific T cell responses and drive tumor reduction in vivo
SQZ to also present additional preclinical data on company’s first oncology approach with SQZPBMC-HPV
WATERTOWN, Mass., Nov. 5, 2019 — SQZ Biotechnologies (SQZ), a clinical stage cell therapy company developing innovative treatments for multiple therapeutic areas, today announced the first data highlighting the potential of the company’s activating antigen carrier (AAC) immunotherapy program for oncology indications. The findings will be detailed in a poster presentation at the Society for Immunotherapy of Cancer (SITC) 34th Annual Meeting. SQZ AACs are part of SQZ’s immune-oncology pipeline, which also includes SQZ Antigen Presenting Cells (APCs).
“We are thrilled to unveil our AAC program to the oncology community this weekend at SITC,” said Armon Sharei, Ph.D., founder and chief executive officer of SQZ. “AACs leverage our platform’s unique capability to create a cell therapy that can engineer the body’s physiological processes to activate and enhance an antigen-specific immune response. We are encouraged by our data and believe this cell therapy approach could underpin a broad range of on-demand cell therapy products targeting solid and liquid tumors.”
The SQZ AAC program utilizes red blood cells (RBCs) as the initial cell source. The RBCs are squeezed with antigen and adjuvant to create AACs. When AACs are administered, they are rapidly taken up by phagocytic cells in the liver and spleen which subsequently present the antigen to both CD8+ and CD4+ T cells, priming a potentially potent anti-tumor T cell response.
The poster, entitled “Activating Antigen Carriers for Cancer Therapy: Preclinical Immune Responses Drive Tumor Regression,” highlights preclinical in vivo and in vitro data demonstrating the potential of SQZ AACs as an immunotherapy for oncology indications. Findings include:
• In mice, AACs are taken up primarily by the liver and spleen, engulfed by macrophages and dendritic cells (DCs), and cleared from the blood within 60 minutes
• AACs prime endogenous CD8+ T cell responses to protein and peptide antigens – demonstrating that they effectively and specifically induce MHC-I presentation in vivo
• Prophylactic treatment with SQZ AACs prevents tumor formation in all treated mice
• Therapeutic treatment with SQZ AACs delays tumor growth; AAC-treated mice display significantly lower tumor volume and extended median survival relative to untreated mice — at a time point when all untreated mice succumbed to disease, 80% of treated mice survived
• TIL analysis of treated mice demonstrates ~100x increase in the CD8+ to regulatory T cell ratio as a result of AAC treatment; over 80% of infiltrating CD8+ T cells are specific to the target antigen
• In mice treated with AACs, tumor regression is significantly correlated with an influx of antigen-specific CD8+ T cells in vivo (R2 = 0.8; p < 0.05), demonstrating that AACs function as mechanistically expected • In vitro studies of AACs created from human RBCs show that AACs are efficiently delivered, engulfed by DCs, and promote antigen specific CD8+ T cell activation
A second poster to be presented at SITC, entitled “Antigen delivery to PBMCs by microfluidic squeezing primes anti-tumor immunity”, details additional preclinical data on the company’s first cell therapy approach to oncology, SQZ APCs, a clinical stage product currently starting phase 1 trials for the treatment of HPV16+ cancers. Pre-clinical data in mice demonstrate that treatment with SQZ-PBMC-HPV leads to tumor regression and the expansion of tumor specific CD8+ T cells as well as enhanced survival. The data support the planned first-in-human study for SQZ-PBMC-HPV (NCT04084951). Both SQZ posters will be presented on Saturday, November 9 from 7:00am-8:30pm EST in the Poster Hall at the Gaylord National Hotel & Convention Center. More details can be found on the conference website at www.sitcancer.org/2019/home.
About SQZ Biotech
SQZ Biotech is a privately held, clinical stage company creating innovative treatments by transforming cells into sophisticated therapeutics. Using its proprietary platform, SQZ has the unique ability to precision engineer virtually any cell type and deliver multiple materials, potentially resulting in powerful, multifunctional cell therapies for a range of diseases with an initial focus on cancer and autoimmune disease. The initial applications for the company leverage SQZ’s ability to generate target-specific immune responses, both in activation for the treatment of solid tumors, and immune suppression for the treatment of auto- immune diseases. For more information please visit www.sqzbiotech.com.
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