X0306 4 2020-07-28 0 0001808865 iTeos Therapeutics, Inc. ITOS 0001465914 Davis Aaron I. C/O ITEOS THERAPEUTICS, INC. 139 MAIN STREET CAMBRIDGE MA 02142 1 0 1 0 Common Stock 2020-07-28 4 C 0 2943568 A 2943568 I See Footnote Common Stock 2020-07-28 4 C 0 48691 A 48691 I See Footnote Common Stock 2020-07-28 4 P 0 1401448 19.00 A 4345016 I See Footnotes Common Stock 2020-07-28 4 P 0 23552 19.00 A 72243 I See Footnotes Series B-2 Preferred Stock 2020-07-28 4 C 0 9593086 D Common Stock 2943568 0 I See Footnote Series B-2 Preferred Stock 2020-07-28 4 C 0 158687 D Common Stock 48691 0 I See Footnote Each share of Series B-2 Convertible Preferred stock is convertible at any time, at the Reporting Person's election, into Common Stock, based on the then-applicable conversion rate and has no expiration date. The shares of Series B-2 Convertible Preferred stock held by Boxer Capital, LLC ("Boxer Capital") will convert automatically into 2,943,568 shares of Common Stock upon the closing of the Issuer's initial public offering. The shares of Series B-2 Convertible Preferred stock held by MVA Investors, LLC ("MVA Investors") will convert automatically into 48,691 shares of Common Stock upon the closing of the Issuer's initial public offering. These amounts reflect a 1-for-3.3115 reverse stock split which became effective on July 20, 2020. These securities are owned directly by Boxer Capital, which may be deemed to be a member of a "group" for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, consisting of (i) Boxer Capital, (ii) Boxer Asset Management Inc., (iii) MVA Investors, (iv) Aaron I. Davis, and (v) Joe Lewis (collectively, the "Boxer Group"). Each member of the Boxer Group other than Boxer Capital disclaims beneficial ownership of these securities to the extent it does not have a pecuniary interest therein. These securities are owned directly by MVA Investors. Each member of the Boxer Group other than MVA Investors disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein. On July 28, 2020, Boxer Capital purchased 1,401,448 shares of Common Stock of the Issuer at a price of $19.00 per share pursuant to an underwritten public offering.. On July 28, 2020, MVA Investors purchased 23,552 shares of Common Stock of the Issuer at a price of $19.00 per share pursuant to an underwritten public offering. /s/ Michel Detheux, as Attorney-in-Fact 2020-07-30