X0306 4 2021-03-30 0 0001835579 Ikena Oncology, Inc. IKNA 0001030575 FORMELA JEAN FRANCOIS C/O IKENA ONCOLOGY, INC. 645 SUMMER STREET, SUITE 101 BOSTON MA 02210 1 0 0 0 Common Stock 2021-03-30 4 P 0 125000 16.00 A 874634 I See footnote Common Stock 2021-12-10 4 S 0 11989 15.03 D 1256224 I See footnote Common Stock 2021-12-13 4 S 0 8330 14.64 D 1247894 I See footnote Common Stock 2021-12-14 4 S 0 5959 14.00 D 1241935 I See footnote Common Stock 2901609 I See footnote The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims Section 16 beneficial ownership of such shares, except to the extent of his pecuniary interest therein, if any. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.60 to $15.55 inclusive. The Reporting Persons undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (4). The shares are held directly by Atlas Venture Fund XI, L.P. ("Atlas Venture Fund XI"). The general partner of Atlas Venture Fund XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of Associates XI LLC and disclaims Section 16 beneficial ownership of such shares, except to the extent of his pecuniary interest therein, if any. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.60 to $14.65 inclusive. These shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). Atlas Venture Associates X, L.P. ("AVA X LP") is the general partner of Atlas Venture Fund X. Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. The Reporting Person is a member of AVA X LLC and disclaims Section 16 beneficial ownership of such shares, except to the extent of his pecuniary interest therein, if any. /s/ Ommer Chohan, as Attorney-in-Fact for Jean Francois Formela 2021-12-14