Updated Data as of December 1, 2021 from Phase 1/2 study of IO102-IO103 in Combination with Nivolumab in Metastatic MelanomaThree-year Survival Probability of 73%Subgroup analyses including patients with poor prognosis NEW YORK, April 08, 2022 (GLOBE NEWSWIRE) — IO Biotech (Nasdaq: IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulating cancer therapies based on its T-win® technology platform, announced today updated efficacy data and subgroup analyses from the MM1636 Phase 1/2 clinical trial evaluating IO102-IO103 as investigational agents in metastatic melanoma in an e-poster presentation at the American Association of Cancer Research conference (AACR), being held April 8-13, 2022 in New Orleans, Louisiana. “We are excited to present these further data demonstrating three-year survival probability of 73% for IO102-IO103 in combination with nivolumab in patients with metastatic melanoma,” said Mai-Britt Zocca, Ph.D., President and CEO of IO Biotech. “Based on these data, clinical activity of the combination of IO102-IO103 with nivolumab is encouraging. We look forward to advancing IO102-IO103 through clinical development to deliver a new treatment option for patients in need.” Data highlights from the e-poster titled, “High clinical efficacy in poor prognosis patients with metastatic melanoma treated with an IDO/PD-L1 peptide vaccine in combination with nivolumab” are outlined below: All 30 patients were evaluated after completing the IDO-PD-L1 vaccination schedule in combination with nivolumab as of the December 1, 2021 data cut-off and after a median follow up of 2.7 yearsthe three-year OS probability was 73%the median progression free survival (mPFS) was 25.3 months. Confirmed overall response rate was 73% with 46.7% of patients obtaining complete responses in poor prognosis patients; a response rate of 81.8% (mPFS: 30.9 months) was seen in patients with elevated baseline LDH-levels; in patients classified as M1c at baseline response rate was 88.2%, (mPFS: 25.6 months)In a subgroup analysis, a response rate of 94.1% was observed in PD-L1+ patients (mPFS: 30.9 months) and 61.5% in PD-L1(-) patients (mPFS: 7.2 months) Immune-related adverse events were comparable to those in patients receiving nivolumab monotherapy. No additional toxicity was observed in poor prognosis patients About the MM1636 Clinical Trial The MM1636 trial (ClinicalTrials.gov: NCT03047928), an investigator-initiated trial at the Copenhagen University Hospital, Herlev, enrolled 30 patients with metastatic melanoma. In this Phase 1/2 clinical trial, patients received the multi-antigen immunotherapeutic, IO102-IO103, in combination with the anti-programmed death 1 (PD-1) antibody nivolumab as first line treatment. Patients were treated with nivolumab according to the approved label for melanoma (3mg/kg bi-weekly for up to two years). IO102-IO103 was given from the start of administration of nivolumab and every second week for the first six weeks and thereafter, every fourth week for 41 weeks. The trial objectives were to assess safety, immune response in blood and biopsies as well as efficacy. About IO Biotech IO Biotech is a clinical-stage biopharmaceutical company developing novel, immune-modulating cancer therapies based on its T-win® technology platform. The T-win® platform is a novel approach to cancer immunotherapy designed to activate naturally occurring T cells to target immunosuppressive mechanisms. IO Biotech is advancing in clinical studies its lead immuno-oncology candidate, IO102-IO103, targeting IDO and PD-L1, and through clinical and preclinical development its other pipeline candidates. IO Biotech is headquartered in Copenhagen, Denmark and has additional offices within the United States (New York, New York and Rockville, Maryland) and United Kingdom (Monmouthshire). For further information, please visit www.iobiotech.com 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 regarding results and plans of pending and future clinical trials, 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. Company Contact: Mai-Britt Zocca, Ph.D.President and CEO IO Biotech, Inc.mz@iobiotech.com Keith Vendola, M.D.CFOIO Biotech, Inc.kv@iobiotech.com Investor Inquiries:Corey Davis, Ph.D.LifeSci Advisors212-915-2577cdavis@lifesciadvisors.com Media Contact:Raena Mina, Ph.D.LifeSci Communications646-606-1438rmina@lifescicomms.com