IO Biotech Presents Pre-Clinical Data Highlighting the Potential of Additional Therapeutic Cancer Vaccine Candidates at the 2025 Annual Meeting of the Society for Immunotherapy of Cancer (SITC)

• Pre-clinical data for IO Biotech’s next T-win vaccine candidate, IO112 targeting arginase 1, demonstrates anti-tumor activity with dynamic changes in the tumor microenvironment (TME) driven by the vaccine-targeted modulation of immunosuppressive myeloid cells, including tumor-associated macrophages (TAMs)
• Pre-clinical data for IO Biotech’s additional T-win vaccine candidate, IO170 targeting Transforming Growth Factor (TGF)-β, demonstrates induction of immune responses that could inhibit tumor growth and reduce lung metastasis
• Data presented at the Society for Immunotherapy of Cancer’s Annual Meeting

NEW YORK, Nov. 07, 2025 (GLOBE NEWSWIRE) — IO Biotech (Nasdaq: IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulatory, off-the-shelf therapeutic cancer vaccines, today announced new pre-clinical data for IO Biotech’s next vaccine candidate, IO112, and additional candidate, IO170, will be presented at the Society for Immunotherapy of Cancer’s 40th Annual Meeting (SITC 2025) in Maryland on November 5-9, 2025.

“This new data is extremely important for our development path as it points toward more potential indications for our novel, immune-modulatory therapeutic vaccines to treat patients with a range of cancers,” said Mai-Britt Zocca, PhD, President and CEO of IO Biotech. “We look forward to advancing our cancer immunotherapy pipeline and expect to file an Investigational New Drug Application for IO112, our next candidate expected to enter clinical development, in 2026.”

Pre-clinical data from IO112, IO Biotech’s second therapeutic cancer vaccine candidate derived from the company’s T-win^® platform, presented at SITC 2025
Arginase 1 (Arg1) plays a central role in immune suppression, and its over-expression has been reported in several cancers including renal cell carcinoma, pancreatic cancer, and head and neck cancer. Importantly, all immune suppressive myeloid cells in the TME express Arg1, and their key roles in cancer immune resistance mechanisms have been well described. The data presented in the poster showcase that IO112 vaccination leads to robust expansion of Arg1-specific T cells, which in turn directly target and reprogram immune suppressive myeloid cells, including TAMs, leading to tumor growth inhibition.

Pre-clinical data from IO170, IO Biotech’s third therapeutic cancer vaccine candidate derived from the company’s T-win^® platform, also presented at SITC 2025
Activation of the TGF-β signaling cascade plays an essential role in a wide range of tumors and other diseases. Cancer cells and components of the tumor microenvironment (e.g. fibroblasts, immune cells, and blood vessels) exploit this pathway to support disease progression during tumor evolution. Nonetheless, global inhibition strategies targeting the TGF-β pathway in clinical studies thus far fell short of the anticipated success. The data presented in this poster showcase an alternative approach, where TGF-β-specific T cells are activated through a peptide vaccination to target TGF-β-expressing cells to promote anti-tumor activities in a cancer model.

“These preclinical data illustrate the potential of additional peptide vaccines based on our proprietary T-Win^® platform with our unique approach directed against both tumor cells and the most important immune-suppressive cells in the tumor microenvironment (TME),” said Ayako Wakatsuki Pedersen, PhD, Senior Vice President of Translational Research at IO Biotech. “Our second investigational therapeutic vaccine candidate, IO112 targeting arginase 1, demonstrates dynamic changes in the TME with anti-tumor activity driven by the vaccine-targeted modulation of immunosuppressive myeloid cells, including tumor-associated macrophages (“TAMs”), shifting the balance from an immunosuppressive to a pro-inflammatory microenvironment, leading to effective anti-tumor responses. Importantly, this clearly distinguishes from the MoA of a different approach to only targeting Arg1 enzymatic activities.”

Dr. Pedersen added, “We also presented new preclinical data for the third peptide vaccine utilizing our T-Win platform, IO170 targeting transforming growth factor (TGF-β), that demonstrated significant tumor growth inhibition and the reduction of lung metastasis in a cancer model. The data for both IO112 and IO170 support further investigation as to how these unique immunomodulatory approaches can serve as strategies to treat a wide range of cancer indications.”

The posters can be found on the “Posters & Publications” page of the IO Biotech website.

Details for the presentations are below:

Title: A TGFβ-directed immune-modulatory vaccine leads to T cell activation, tumor growth inhibition and reduces metastases
Presenters: Ulla Kring Hansen, Senior Scientist, Translational Research, IO Biotech
Abstract/Poster number: 929
Date: Friday, November 7, 2025
Location: Exhibit Halls AB – Gaylord National Resort & Convention Center
Times: Poster session 12:15 – 1:45 p.m. ET; Poster reception 5:35-7:00 p.m. ET

Title: Induction of T cell immunity against arginase 1 (Arg1)+ myeloid cells is a unique feature that differentiates tumor growth suppression of Arg1 immune-modulatory vaccines from that of Arg1 inhibitors.
Presenters: Inés Lecoq Molinos, Senior Scientist, Translational Research, IO Biotech
Abstract/Poster number: 932
Date: Saturday, November 8, 2025
Location: Exhibit Halls AB – Gaylord National Resort & Convention Center
Times: Poster session 12:15 – 1:45 p.m. ET; Poster reception 5:10-6:35 p.m. ET

About IO Biotech

IO Biotech is a clinical-stage biopharmaceutical company developing novel, immune-modulatory, off-the-shelf therapeutic cancer vaccines based on its T-win® platform. The T-win platform is based on a novel approach to cancer vaccines designed to activate T cells to target both tumor cells and the immune-suppressive cells in the tumor microenvironment. IO Biotech is advancing its lead cancer vaccine candidate, Cylembio®, in clinical trials, and additional pipeline candidates through preclinical development. IO Biotech is headquartered in Copenhagen, Denmark and has US headquarters in New York, New York.

For further information, please visit www.iobiotech.com. Follow us on our social media channels on LinkedIn and X (@IOBiotech).

Forward-Looking Statement

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements, including statements regarding the timing or outcome of communications with regulatory authorities including the FDA, the timing or outcome of the submission of regulatory applications, including an IND for IO112, and statements regarding other current or future clinical trials, their timing, progress, enrollment or results, or the company’s financial position or cash runway, are based on IO Biotech’s current assumptions and expectations of future events and trends, which affect or may affect its business, strategy, operations or financial performance, and actual results and other events may differ materially from those expressed or implied in such statements due to numerous risks and uncertainties. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Because forward-looking statements are inherently subject to risks and uncertainties, you should not rely on these forward-looking statements as predictions of future events. These forward-looking statements speak only as of the date hereof and should not be unduly relied upon. Except to the extent required by law, IO Biotech undertakes no obligation to update these statements, whether as a result of any new information, future developments or otherwise.

Contact:

Investors and media:
Maryann Cimino, Director of Investor Relations & Corporate Communications
IO Biotech, Inc.
617-710-7305
mci@iobiotech.com