X0306 4 2021-06-02 0 0001528115 Annexon, Inc. ANNX 0001790589 Sun Ricky C/O BAIN CAPITAL LIFE SCIENCES INVESTORS 200 CLARENDON STREET BOSTON MA 02116 1 0 0 0 Stock Option (Right to Buy) 21.03 2021-06-02 4 A 0 10000 0.00 A 2031-06-02 Common Stock 10000 10000 D The underlying shares subject to the option vest and become exercisable as to 100% of the total number of shares subject to the option on the earlier of (i) the first anniversary of June 2, 2021 or (ii) the next Annual Meeting following June 2, 2021, subject to Reporting Person's continuous service as a director until such vesting date. /s/ Ricky Sun 2021-06-04