SC 13D/A

NUMBER OF

SHARES

BENEFICIALLY

OWNED BY

EACH

REPORTING

PERSON

WITH

SOLE VOTING POWER

1,820,423

SHARED VOTING POWER

0

SOLE DISPOSITIVE POWER

1,820,423

SHARED DISPOSITIVE POWER

0

SC 13D/A 1 d216705dsc13da.htm SC 13D/A SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Annexon, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

03589W102

(CUSIP Number)

Robert Liptak

Clarus Ventures, LLC

101 Main Street, Suite 1210

Cambridge, MA 02142

(617) 949-2200

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 18, 2021

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

*	The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Clarus Lifesciences III, L.P.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Clarus Ventures III GP, L.P.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Blackstone Clarus III L.L.C.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Blackstone Holdings II L.P.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Blackstone Holdings I/II GP L.L.C.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Blackstone Inc.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Blackstone Group Management L.L.C.
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION Delaware

CUSIP No. 03589W102


1		NAMES OF REPORTING PERSONS Stephen A. Schwarzman
2		CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ☐ (b) ☒
3		SEC USE ONLY
4		SOURCE OF FUNDS (SEE INSTRUCTIONS) OO
5		CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(D) OR 2(E) ☐
6		CITIZENSHIP OR PLACE OF ORGANIZATION United States

This Amendment No. 1 (“Amendment No. 1”) to the statement on Schedule 13D amends and supplements the initial statement on Schedule 13D filed on August 10, 2020 (as amended, the “Schedule 13D”), relating to the common stock, par value $0.001 per share (the “Common Stock”) of Annexon, Inc., a Delaware corporation (the “Issuer”).

Certain terms used but not defined in this Amendment No. 1 have the meanings assigned thereto in the Schedule 13D. Except as specifically provided herein, this Amendment No. 1 does not modify any of the information previously reported in the Schedule 13D.

Item 5.

Interest in Securities of the Issuer

Item 5 of the Schedule 13D is hereby amended and restated as follows:

(a) and (b) Calculations of the percentage of the shares of Common Stock beneficially owned assumes that there were 38,332,276 shares of Common Stock outstanding as of August 10, 2021, based on information set forth in the prospectus on Quarterly Report on Form 10-Q filed by the Issuer on August 16, 2021.

The aggregate number and percentage of the Common Stock beneficially owned by each Reporting Person and, for each Reporting Person, the number of shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Schedule 13D and are incorporated herein by reference.

As of the date hereof, the Fund directly holds 1,820,423 shares of Common Stock.

Clarus GP is the general partner of the Fund. Blackstone Clarus III L.L.C. is the general partner of Clarus GP. The sole member of Blackstone Clarus III L.L.C. is Blackstone Holdings II L.P. The general partner of Blackstone Holdings II L.P. is Blackstone Holdings I/II GP L.L.C. The sole member of Blackstone Holdings I/II GP L.L.C. is Blackstone Inc. The sole holder of the Series II preferred stock of Blackstone Inc. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly-owned by Blackstone’s senior managing directors and controlled by its founder, Stephen A. Schwarzman.

Neither the filing of this Schedule 13D nor any of its contents shall be deemed to constitute an admission that any Reporting Person is the beneficial owner of the Common Stock referred to herein for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, or for any other purpose and each of the Reporting Persons expressly disclaims beneficial ownership of such shares of Common Stock.

Any beneficial ownership of Common Stock by any of the persons listed on Schedule I is set forth on Schedule I attached to the original Schedule 13D.

(c) On August 18, 2021, the Fund distributed 910,212 shares of Common Stock to its limited partners, including Clarus GP (the “Fund Distribution”). Clarus GP then distributed the 124,745 shares it received in the Fund Distribution to its limited partners. Except as set forth above, none of the Reporting Persons has effected any transaction in the Common Stock during the last 60 days.

(d) To the best knowledge of the Reporting Persons, no one other than the Reporting Persons, or the partners, members, affiliates or shareholders of the Reporting Persons, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock reported herein as beneficially owned by the Reporting Persons.

(e) As of August 18, 2021, the Reporting Persons ceased to be the beneficial owners of more than five percent of the outstanding Common Stock.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: August 27, 2021


CLARUS LIFESCIENCES III, L.P.

By:		Clarus Ventures III GP, L.P., its general partner
By:		Blackstone Clarus III, L.L.C., its general partner
By:		Blackstone Holdings II L.P., its managing member
By:		Blackstone Holdings I/II GP L.L.C., its general partner

By:		/s/ Tabea Hsi
Name: Tabea Hsi
Title: Senior Managing Director

CLARUS VENTURES III GP, L.P.

By:		Blackstone Clarus III, L.L.C., its general partner
By:		Blackstone Holdings II L.P., its managing member
By:		Blackstone Holdings I/II GP L.L.C., its general partner

By:		/s/ Tabea Hsi
Name: Tabea Hsi
Title: Senior Managing Director

BLACKSTONE CLARUS III L.L.C.

By:		Blackstone Holdings II L.P., its managing member
By:		Blackstone Holdings I/II GP L.L.C., its general partner

By:		/s/ Tabea Hsi
Name: Tabea Hsi
Title: Senior Managing Director

BLACKSTONE HOLDINGS II L.P.

By:		Blackstone Holdings I/II GP L.L.C., its general partner

By:		/s/ Tabea Hsi
Name: Tabea Hsi
Title: Senior Managing Director


BLACKSTONE HOLDINGS I/II GP L.L.C.

By:		/s/ Tabea Hsi
Name: Tabea Hsi
Title: Senior Managing Director

BLACKSTONE INC.

By:		/s/ Tabea Hsi
Name:		Tabea Hsi
Title:		Senior Managing Director

BLACKSTONE GROUP MANAGEMENT L.L.C.

By:		/s/ Tabea Hsi
Name:		Tabea Hsi
Title:		Senior Managing Director

/s/ Stephen A. Schwarzman
Stephen A. Schwarzman

[Annexon, Inc. – Schedule 13D/A]

SEC Form SC 13D/A filed by Annexon, Inc. (Amendment)