Exhibit 99.1 IO Biotech Reports First Quarter 2024 Financial Results and Provides Business Highlights • Outcome of interim analysis for the overall response rate (ORR) for the first 225 patients randomized in the pivotal Phase 3 trial (IOB-013/KN-D18) of lead investigational therapeutic cancer vaccine, IO102-IO103, in combination with pembrolizumab still expected in Q3 2024; outcome of primary endpoint of progression free survival (PFS) is now projected to occur in first half of 2025 • Completed enrollment ...