IO Biotech, Inc.: directors' dealings · United States · SEC (Form 4)

About IO Biotech, Inc.

IO Biotech, Inc. is a U.S.-listed clinical-stage biopharmaceutical company trading on Nasdaq (United States) under the ticker IOBT. The company is focused on immuno-oncology and is developing off-the-shelf therapeutic cancer vaccines designed to modulate the tumor microenvironment and enhance anti-tumor immune responses. Its proprietary T-win® platform aims to target both tumor cells and immunosuppressive cells within the tumor microenvironment, with the strategic objective of converting “cold” tumors into more inflamed, treatment-responsive disease states. From a corporate-history standpoint, IO Biotech has strong Scandinavian roots with a transatlantic footprint. SEC filings show that the company is headquartered in Copenhagen, Denmark, and also maintains a U.S. headquarters in New York, New York. The company’s public-market debut came in November 2021, when it began trading on the Nasdaq Global Market. This dual presence reflects a common biotech operating model: discovery and development centered around the company’s scientific base in Europe, with capital-markets access and investor relations anchored in the United States. The lead asset is Cylembio® (imsapepimut and etimupepimut, adjuvanted), also known historically as IO102-IO103. This investigational vaccine is being evaluated primarily in combination with PD-1 inhibitors such as pembrolizumab (KEYTRUDA®) in advanced melanoma and in other solid-tumor settings. Beyond its lead program, IO Biotech is advancing additional preclinical candidates, including IO112, which targets arginase 1, and IO170, which targets TGF-β. That broader pipeline suggests a platform strategy rather than a single-asset story: IO Biotech is trying to build a family of therapeutic vaccines that address distinct immunosuppressive pathways. In competitive terms, IO Biotech operates in a highly crowded oncology immunotherapy landscape dominated by large pharmaceutical groups and well-capitalized biotech peers. Its differentiation lies in the novelty of the T-win mechanism, the off-the-shelf nature of its vaccine candidates, and the potential to combine with existing checkpoint inhibitors rather than compete head-on with them. If the clinical signal holds, that could be meaningful in high-unmet-need indications such as melanoma, non-small cell lung cancer, and head and neck cancer. Recent company highlights have centered on clinical execution and regulatory dialogue. In 2025, IO Biotech reported five-year clinical outcomes from an earlier phase 1/2 study, advanced enrollment and data generation across phase 2 programs, and disclosed pivotal phase 3 results for Cylembio in advanced melanoma. The company also referenced ongoing discussions with the FDA regarding the next development and filing path. For investors, IO Biotech remains a classic data-dependent biotech: the upside case is driven by clinical differentiation and regulatory progress, while the key risks are typical of development-stage oncology companies, including trial outcomes, financing needs, and commercialization uncertainty.