IO Biotech

About IO Biotech

IO Biotech (Nasdaq: IOBT) is a clinical-stage biopharmaceutical firm, established in December 2014, developing therapies to combat cancer. The company was founded by Dr. Mai-Britt Zocca, who currently serves as CEO, and Professor Mads Hald Andersen, leveraging their deep expertise in immunology and oncology. Dr. Zocca has a Ph.D. in tumor immunology from the University of Copenhagen and NIH, NCI, and has founded several other biotech companies, bringing extensive experience in translational and clinical immuno-oncology.

The company's core focus is its proprietary T-win® technology platform, which engineers "off-the-shelf" therapeutic cancer vaccines. This platform has a dual-action mechanism designed to activate the patient's own T cells to simultaneously target and kill both cancer cells and the immune-suppressive cells within the tumor microenvironment (TME). By disrupting key immunosuppressive pathways mediated by proteins like IDO (indoleamine 2,3-dioxygenase) and PD-L1, the T-win vaccines aim to create a powerful, durable anti-tumor response. This approach differs from many immunotherapies that block a single pathway or personalized vaccines that must be created for each patient.

IO Biotech's lead product candidate is Cylembio (also known as IO102-IO103), a vaccine targeting IDO and PD-L1. In August 2025, the company announced results from a pivotal Phase 3 trial for Cylembio combined with pembrolizumab for advanced melanoma. While the trial narrowly missed its primary endpoint for statistical significance (p=0.056), it demonstrated a notable clinical improvement, extending median progression-free survival to 19.4 months in the combination arm versus 11.0 months for the control group. Based on the totality of the data, which showed encouraging trends, IO Biotech plans to engage with the FDA to discuss a potential path to approval. The company is also advancing other candidates, like IO112 targeting arginase-1 (Arg1), with plans for an IND submission in 2025.

Headquartered in Copenhagen, Denmark, with a U.S. base in New York, IO Biotech operates as a publicly traded company. The company went public in November 2021, raising approximately $115.1 million in its initial public offering. Its business model centers on advancing its pipeline through clinical trials and research, funded by equity and strategic financing. As a clinical-stage company, it does not currently generate revenue from product sales but relies on capital from investors and potential future revenue from licensing agreements, milestone payments, and royalties upon commercialization.