SCHEDULE 13G/A 0001750698 XXXXXXXX LIVE 1 Common stock, par value $0.001 per share 09/30/2025 0001865494 IO Biotech, Inc. 449778109 Ole MaalOes Vej 3 Copenhagen N G7 DK-2200 Rule 13d-1(c) Vivo Capital IX, LLC b DE 0.00 0.00 0.00 0.00 0.00 N 0 OO Vivo Capital Fund IX, L.P. b DE 0.00 0.00 0.00 0.00 0.00 N 0 PN Vivo Opportunity, LLC b DE 3157894.00 0.00 3157894.00 0.00 3157894.00 N 4.6 OO The number represents 3,157,894 shares of common stock, par value $ 0.001 per share (the "Common Stock") of IO Biotech, Inc. (the "Issuer"), issuable upon exercise of certain warrants. All securities are held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. Based on the sum of (i) 65,880,914 shares of Common Stock outstanding of the Issuer as of August 11, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (the "SEC") on August 14, 2025, and (ii) 3,157,894 shares of Common Stock, issuable upon exercise of the warrants held of records by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity Fund Holdings, L.P. b DE 3157894.00 0.00 3157894.00 0.00 3157894.00 N 4.6 PN The number represents 3,157,894 shares of Common Stock of the Issuer, issuable upon exercise of certain warrants. All securities are held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. Based on the sum of (i) 65,880,914 shares of Common Stock outstanding of the Issuer as of August 11, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the SEC on August 14, 2025, and (ii) 3,157,894 shares of Common Stock, issuable upon exercise of the warrants held of records by Vivo Opportunity Fund Holdings, L.P. IO Biotech, Inc. Ole MaalOes Vej 3, Copenhagen N, Denmark, DK-2200. Vivo Capital IX, LLC Vivo Capital Fund IX, L.P. Vivo Opportunity, LLC Vivo Opportunity Fund Holdings, L.P. 192 Lytton Avenue, Palo Alto, CA 94301 Delaware limited liability company. Y VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 SHARES VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 SHARES VIVO CAPITAL IX, LLC: 0% VIVO CAPITAL FUND IX, L.P.: 0% VIVO OPPORTUNITY, LLC: 4.6% VIVO OPPORTUNITY FUND HOLDINGS, L.P.: 4.6% VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 shares VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 shares 0 VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 shares VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 shares 0 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Vivo Capital IX, LLC /s/ Frank Kung 11/14/2025 Vivo Capital Fund IX, L.P. /s/ Frank Kung 11/14/2025 Vivo Opportunity, LLC /s/ Kevin Dai 11/14/2025 Vivo Opportunity Fund Holdings, L.P. /s/ Kevin Dai 11/14/2025