X0407 4 2023-06-13 0 0001808865 iTeos Therapeutics, Inc. ITOS 0001792061 DiRocco Derek C/O ITEOS THERAPEUTICS, INC. 321 ARSENAL STREET WATERTOWN MA 02472 1 0 0 0 0 Stock Option (Right to Buy) 14.77 2023-06-13 4 A 0 22383 0.00 A 2024-06-13 2033-06-13 Common Stock 22383 22383 D Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the stock option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund") and the RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund and the Nexus Fund. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying Common Stock. /s/ Adi Osovsky, as Attorney-in-Fact 2023-06-15