IO-112

Completed enrollment of pivotal Phase 3 trial of lead investigational therapeutic cancer vaccine, IO102-IO103, in combination with KEYTRUDA® (pembrolizumab), in patients with advanced melanoma; planned interim analysis for overall response rate (ORR) expected in third quarter of 2024 by independent data monitoring committeeProgressed clinical development of IO102-IO103 with first patient dosed in Phase 2 basket trial of IO102-IO103 in combination with pembrolizumab as neoadjuvant and adjuvant treatment of patients with resectable solid tumorsEnded 2023 with cash and cash equivalents of approximately $143.2 million; expected operational runway into the fourth quarter of 2025 NEW YORK, March 05, 2024 (GLOBE NEWSWIRE) -- IO Biotech (Nasdaq: IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulating therapeutic cancer vaccines based on its T-win® platform, today reported financial results for the fourth quarter and year-ended December 31, 2023. “In 2023, we reached a significant milestone in our pivotal Phase 3 trial evaluating our lead therapeutic cancer vaccine, IO102-IO103, in combination with KEYTRUDA, completing enrollment in this trial in mid-November,” said Mai-Britt Zocca, Ph.D., President and CEO of IO Biotech. “The acceleration in enrollment observed in this study in the second half of 2023 is a testament to the need that exists today for more efficacious and better tolerated first-line treatment options for patients with advanced melanoma.” Dr. Zocca continued, “The coming months will prove to be a critical period in the development of IO Biotech, with the outcome of the pivotal Phase 3 interim analysis expected in the third quarter of 2024, and, more importantly, the primary endpoint of progression free survival estimated to follow in the second half of 2025. Our team is dedicated to continuing our diligent work to efficiently bring IO102-IO103 to patients in need, potentially as early as 2025.” Fourth Quarter 2023 and other Recent Highlights In November 2023, the company completed enrollment of 380 patients in its pivotal Phase 3 trial (IOB-013/KN-D18) of IO102-IO103 in combination with Merck’s anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in advanced melanoma. The primary endpoint of the pivotal Phase 3 trial is progression free survival (PFS). The PFS analysis is event-driven and will be conducted when 226 events have occurred in the trial, which the company estimates will take place in the second half of 2025. Additionally, a planned interim analysis of overall response rate (ORR) will be conducted when the first 225 randomized patients reach one year of treatment in June 2024. The outcome of this analysis is expected in the third quarter of 2024.In December 2023, the first patient was dosed in the company’s Phase 2 solid tumor basket trial (IOB-032/PN-E40) studying treatment with IO102-IO103 in combination with pembrolizumab given before (neo-adjuvant) and after (adjuvant) surgery with curative intent in patients with resectable melanoma or squamous cell carcinoma of the head and neck (SCCHN).The company’s Phase 2 basket trial (IOB-022/KN-D38) evaluating IO102-IO103 in combination with pembrolizumab in patients with metastatic non-small cell lung cancer (NSCLC) or recurrent or metastatic SCCHN is ongoing. Encouraging preliminary data that support the potential of IO102-IO103 in combination with pembrolizumab as first-line treatment in NSCLC and SCCHN were presented at the IASLC 2023 World Conference on Lung Cancer (WCLC) in September 2023 and at the European Society of Medical Oncology (ESMO) annual meeting in October 2023.Progress continued in several investigator-initiated trials the company is supporting including dosing of the first patient in the Phase 2 trial evaluating its lead therapeutic cancer vaccine candidate, IO102-IO103, and pembrolizumab as neoadjuvant followed by adjuvant treatment of patients with SCCHN (NCT05977907), as well as continuing enrollment in both the Phase 2 trial of IO102-IO103 given in combination with nivolumab-relatlimab in patients with untreated, unresectable Stage III/IV melanoma (NCT05912244) and the Phase 1 study of the IO102-IO103 vaccine in combination with pembrolizumab for patients with BCG-unresponsive or intolerant high-risk non-muscle invasive bladder cancer (NCT05843448).Three posters were presented at the Society for Immunotherapy of Cancer’s (SITC) 38th Annual Meeting in November 2023 with data providing further evidence of the differential biological impact of therapeutic vaccines IO102, IO103 and IO112.The company expanded its Board of Directors with the appointment of Helen Collins, MD in November 2023. Fourth Quarter 2023 Financial Results Net loss for the three months ended December 31, 2023, was $26.2 million, compared to $20.1 million for the three months ended December 31, 2022.Research and development expenses were $21.8 million for the three months ended December 31, 2023, compared to $14.4 million for the three months ended December 31, 2022. The increase was primarily related to clinical trial-related activities for the company’s IO102-IO103 therapeutic cancer vaccine candidate, including the continued execution of the company’s Phase 3 clinical trial. The company recognized $0.5 million in research and development equity-based compensation for the three months ended December 31, 2023, compared to $0.6 million for the three months ended December 31, 2022.General and administrative expenses were $6.4 million for the three months ended December 31, 2023, compared to $6.0 million for the three months ended December 31, 2022. The increase was primarily related to personnel costs due to an increase in head count that was offset by a decrease in professional services, consultant and other costs. The company recognized $1.0 million in general and administrative equity-based compensation for the three months ended December 31, 2023, compared to $1.1 million for the three months ended December 31, 2022.Cash and cash equivalents as of December 31, 2023 were $143.2 million, compared to $142.6 million at December 31, 2022. During the three months ended December 31, 2023, the company used cash, cash equivalents and restricted cash of $22.9 million from operating and investing activities. About IO102-IO103 IO102-IO103 is an investigational off-the-shelf therapeutic cancer vaccine designed to kill both tumor cells and immune-suppressive cells in the tumor microenvironment (TME) by stimulating activation and expansion of T cells against indoleamine 2,3-dioxygenase (IDO) and/or programmed death-ligand 1 (PD-L1) cells. The company is currently conducting a pivotal Phase 3 trial (IOB-013/KN-D18; NCT05155254) investigating IO102-IO103 in combination with pembrolizumab versus pembrolizumab alone in patients with advanced melanoma, a Phase 2 basket trial (IOB-022/KN-D38; NCT05077709) investigating IO102-IO103 in combination with pembrolizumab as first line treatment in patients with solid tumors, and a Phase 2 basket trial (IOB-032/PN-E40; NCT05280314) investigating IO102-IO103 in combination with pembrolizumab as neo-adjuvant/adjuvant treatment of patients with solid tumors. The clinical trials are sponsored by IO Biotech and conducted in collaboration with Merck and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103. KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA. About the IOB-013/KN-D18 Pivotal Phase 3 Clinical Trial IOB-013/KN-D18 (Clinical Trials.gov: NCT05155254) is an open label, randomized Phase 3 clinical trial of IO102-IO103 in combination with pembrolizumab versus pembrolizumab alone in patients with previously untreated, unresectable or metastatic (advanced) melanoma, being conducted in collaboration with Merck. Patients have been enrolled from centers across the United States, Europe, Australia, Turkey, Israel and South Africa. The primary endpoint of the study is progression free survival. Biomarker analyses will also be conducted. IO Biotech is sponsoring the Phase 3 trial and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103. About the IOB-013/KN-D18 Clinical Trial Endpoints The primary endpoint of the IOB-013/KN-D18 trial is progression free survival (PFS). The PFS analysis is event-driven and will be conducted when 226 events have occurred in the trial, which the company estimates will take place in the second half of 2025. Additionally, there is a planned per-protocol interim analysis of overall response rate when the first 225 randomized patients reach one year of treatment in mid-2024. The outcome of this analysis is expected in the third quarter of 2024. There is a high statistical bar for the Phase 3 interim analysis (p≤0.005), which was set to preserve most of the alpha for the primary endpoint of PFS. Regardless of the outcome of the interim analysis, the trial is designed to continue to the primary PFS endpoint. About IO Biotech IO Biotech is a clinical-stage biopharmaceutical company developing novel, immune-modulating 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 the immunosuppressive cells in the tumor microenvironment. IO Biotech is advancing its lead cancer vaccine candidate, IO102-IO103, in clinical trials, and additional pipeline candidates through preclinical development. Based on positive Phase 1/2 first line metastatic melanoma data, IO102-IO103, in combination with pembrolizumab, has been granted a breakthrough therapy designation for the treatment of advanced melanoma by the US Food and Drug Administration. IO Biotech is headquartered in Copenhagen, Denmark and has US headquarters in New York, New York. 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 the timing of the interim and primary analyses of the company’s Phase 3 trial, current or future clinical trials, their 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:Maryann Cimino, Director of Investor Relations IO Biotech, Inc.617-710-7305mci@iobiotech.com IO BIOTECH, INC. Consolidated Statements of Operations and Comprehensive Loss (Unaudited in thousands, except share and per share amounts) Three Months EndedDecember 31, Year EndedDecember 31, 2023 2022 2023 2022 Operating expenses Research and development $21,770 $14,433 $67,829 $46,986 General and administrative 6,413 5,955 23,614 24,438 Total operating expenses 28,183 20,388 91,443 71,424 Loss from operations (28,183) (20,388) (91,443) (71,424) Other income (expense) Currency exchange gain, net 405 521 331 130 Interest income 1,949 782 5,881 1,411 Interest expense — — — (302)Total other income (expense), net 2,354 1,303 6,212 1,239 Loss before income tax expense (25,829) (19,085) (85,231) (70,185) Income tax expense 353 987 852 1,273 Net loss (26,182) (20,072) (86,083) (71,458) Net loss attributable to common shareholders (26,182) (20,072) (86,083) (71,458) Net loss per common share, basic and diluted $(0.40) $(0.70) $(1.98) $(2.48) Weighted-average number of shares used in computing net loss per common share, basic and diluted 65,880,914 28,815,267 43,539,976 28,815,267 Other comprehensive (loss) income Net loss $(26,182) $(20,072) $(86,083) $(71,458) Foreign currency translation 204 3,775 472 (8,652) Total comprehensive loss $(25,978) $(16,297) $(85,611) $(80,110) IO BIOTECH, INC. Consolidated Balance Sheets (Unaudited in thousands, except share and per share amounts) December 31, 2023 2022 Assets Current assets Cash and cash equivalents $143,193 $142,590 Prepaid expenses and other current assets 4,062 5,629 Total current assets 147,255 148,219 Restricted cash 268 268 Property and equipment, net 847 741 Right of use lease asset 2,259 2,493 Other non-current assets 89 84 Total non-current assets 3,463 3,586 Total assets $150,718 $151,805 Liabilities and stockholders’ equity Current liabilities Accounts payable $3,878 $4,004 Lease liability - current 655 515 Accrued expenses and other current liabilities 11,184 6,157 Total current liabilities 15,717 10,676 Lease liability - non-current 1,839 2,275 Total non-current liabilities 1,839 2,275 Total liabilities 17,556 12,951 Stockholders’ equity Preferred stock, par value of $0.001 per share; 5,000,000 shares authorized,no shares issued and outstanding as of December 31, 2023 and 2022 — — Common stock, par value of $0.001 per share; 300,000,000 shares authorized at December 31, 2023 and December 31, 2022; 65,880,914 and 28,815,267 shares issued and outstanding as of December 31, 2023 and December 31, 2022, respectively 66 29 Additional paid-in capital 406,587 326,705 Accumulated deficit (263,822) (177,739)Accumulated other comprehensive loss (9,669) (10,141)Total stockholders’ equity 133,162 138,854 Total liabilities and stockholders’ equity $150,718 $151,805

NEW YORK, Oct. 03, 2023 (GLOBE NEWSWIRE) -- IO Biotech (Nasdaq: IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulating cancer vaccines based on its T-win® technology platform, announced three poster presentations at the Society for Immunotherapy of Cancer’s 38th Annual Meeting (SITC 2023), to be held in San Diego, California on November 1-5, 2023. Two of the posters will include new in vivo and in vitro data related to IO Biotech’s lead therapeutic cancer vaccine candidate, IO102-IO103, currently being evaluated in a pivotal Phase 3 study. The third poster contains new pre-clinical data for the next candidate in the IO Biotech pipeline, IO112, which targets Arginase 1. Poster Presentations Title: T Cell Receptor Diversity Analysis of in vitro-Expanded T cells Against IDO1 and PD-L1-Derived PeptidesAbstract Number: 1029Presenter: Preeyam Patel, PhD, Senior Scientist, IO BiotechDate: Friday, November 3, 2023Location and time: Poster Hall: 9:00 a.m.– 7:00 p.m. PDT; Poster session Lunch 12:00 –1.30 p.m.; Poster reception 5:10 – 6:40 p.m. Title: Peptide vaccination against PD-L1 reduces tumor growth in preclinical models through stimulation of PD-L1-targeting T cells in the tumor microenvironment Abstract Number: 1468 Presenter: Marion Chapellier, PhD, Senior Scientist, IO Biotech Date: Saturday, November 4, 2023 Location and time: Poster Hall: 9:00 a.m.– 8.30 p.m. PDT; Poster session lunch 11:55 a.m. – 1:25 p.m.; Poster reception 7:00 – 8.30 p.m. Title: Arginase-1 vaccine promotes T cell immunity against arginase 1+ cells, controls tumor growth via immune modulation of tumor microenvironment Abstract Number: 1335 Presenter: Marco Carretta, PhD, Senior Scientist, IO Biotech Date: Friday, November 3, 2023 Location and time: Poster Hall: 9 a.m.– 7 p.m. PDT; Poster session lunch 12:00 – 1.30 p.m.; Poster reception 5:10 – 6:40 p.m. About IO102-IO103 IO102-IO103 is an investigational immune-modulating cancer vaccine designed to target the immunosuppressive mechanisms mediated by the proteins indoleamine 2,3-dioxygenase (IDO) and programmed death-ligand 1 (PD-L1). The company is currently conducting a pivotal Phase 3 trial (IOB-013/KN-D18; NCT05155254) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced melanoma patients, a Phase 2 basket trial (IOB-022/KN-D38; NCT05077709) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced non-small cell lung cancer and head and neck cancer, and a Phase 2 basket trial (IOB-032/PN-E40; NCT05280314) evaluating IO102-IO103 plus pembrolizumab as a perioperative treatment in solid tumors including Melanoma and Squamous Cell Carcinoma of Head and Neck (SCCHN). The clinical trial is sponsored by IO Biotech and conducted in collaboration with Merck. IO Biotech maintains global commercial rights to IO102-IO103. About IOB-032/PN-E40 Phase 2 Basket Trial in Solid Tumors IOB-032/PN-E40, (NCT05280314) is a multi-center, multi-arm basket trial evaluating anti-tumor activity, safety, and immune infiltration of IO102-IO103 in combination with pembrolizumab as neoadjuvant and adjuvant treatment. This proof-of-concept trial will be focused initially on two indications and will include patients with resectable tumors in Melanoma and SCCHN. About IO Biotech IO Biotech is a clinical-stage biopharmaceutical company developing novel, immune-modulating therapeutic cancer vaccines based on its T-win® vaccine platform. The T-win platform is a novel approach to cancer vaccines designed to activate T cells to target the most important immunosuppressive cells in the tumor microenvironment. IO Biotech is advancing in clinical studies its lead cancer vaccine candidate, IO102-IO103, targeting IDO and PD-L1, and through preclinical development its other pipeline candidates. Based on positive Phase 1/2 data, IO102-IO103 has been granted break through designation by the US Food and Drug Administration. IO Biotech is headquartered in Copenhagen, Denmark and has US headquarters in New York, New York. 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 the timing of the interim analysis of our Phase 3 trial, current or future clinical trials, their 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. Company Contact:Maryann Cimino, Director of Investor RelationsIO Biotech, Inc.617-710-7305mci@iobiotech.com