Bain Capital Life Sciences Investors, LLC - May 25, 2023 Form 3 Insider Report for Annexon, Inc. (ANNX)

Role: 10%+ Owner
Signature: Bain Capital Life Sciences Investors, LLC, By: /s/ Ricky Sun, Title: Partner
Stock symbol: ANNX
Transactions as of: May 25, 2023
Transactions value $: $0
Form type: 3
Date filed: 5/30/2023, 09:55 PM
Previous filing: Dec 5, 2022
Next filing: Dec 29, 2023

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	ANNX	Common Stock						5.4M	May 25, 2023	See footnote	F1, F6, F7, F8, F9

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	ANNX	Warrant (right to buy)							May 25, 2023	Common Stock	775K	$5.81	See footnote	F2, F4, F6, F7, F8, F9
holding	ANNX	Pre-Funded Warrant (right to buy)							May 25, 2023	Common Stock	2.74M	$0.00	See footnote	F3, F4, F5, F6, F7, F8, F9

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents 2,940,627 shares of Common Stock held by Bain Capital Life Sciences Fund, L.P. ("BCLS Fund I"), 2,160,298 shares of Common Stock held by BCLS I Investco, LP ("BCLS I Investco") and 301,001 shares of Common Stock held by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS Fund I and BCLS I Investco, the "Bain Capital Life Sciences Entities").
F2	Represents a warrant to purchase 774,943 shares of Common Stock held by BCLS I Investco.
F3	Represents a pre-funded warrant to purchase 2,739,475 shares of Common Stock held by BCLS I Investco.
F4	BCLS I Investco is prohibited from exercising the warrant to purchase Common Stock referred to in footnote (2) above or the pre-funded warrant to purchase Common Stock referred to in footnote (3) above if the Bain Capital Life Sciences Entities would, in the aggregate, beneficially own more than 9.99% of the total number of shares of Common Stock then issued and outstanding immediately after giving effect to such exercise.
F5	The pre-funded warrant does not expire.
F6	Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS Fund I. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund I. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.
F7	BCLS I Investco GP, LLC ("BCLS I Investco GP"), whose manager is BCLS Fund I, is the general partner of BCLS I Investco. As a result, each of BCLSP, BCLS Fund I and BCLS I Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS I Investco. Each of BCLSP, BCLS Fund I and BCLS I Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.
F8	Boylston Coinvestors, LLC is the general partner of BCIPLS.
F9	Bain Capital Life Sciences Investors, LLC ("BCLSI") is the general partner of BCLSP and governs the investment strategy and decision making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.