SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Bain Capital Life Sciences Investors, LLC (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 12/02/2022	3. Issuer Name and Ticker or Trading Symbol Solid Biosciences Inc. [ SLDB ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	3,130,423	I	See footnotes(1)(2)(3)(4)(5)(6)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Bain Capital Life Sciences Investors, LLC (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* BCLS SB Investco, LP (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* Bain Capital Life Sciences Partners, LP (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* Bain Capital Life Sciences Fund II, L.P. (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* Bain Capital Life Sciences Investors II, LLC (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* BCLS II Investco, LP (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* BCLS II Investo (GP), LLC (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* BCIP Life Sciences Associates, LP (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

Explanation of Responses:

1. Represents 2,301,955 shares of the Issuer's Common Stock held by BCLS II Investco, LP ("BCLS II Investco"), 528,661 shares of the Issuer's Common Stock held by BCLS SB Investco, LP ("BCLS SB"), 267,257 shares of the Issuer's Common Stock held by Bain Capital Life Sciences Fund II, L.P. ("BCLS Fund II"), and 32,550 shares of the Issuer's Common Stock held by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS II Investco, BCLS SB and BCLS Fund II, the "Bain Capital Life Sciences Entities").

2. Bain Capital Life Sciences Investors II, LLC ("BCLSI II") is the general partner of BCLS Fund II. As a result, BCLSI II may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund II. BCLSI II disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

3. BCLS II Investco (GP), LLC ("BCLS II Investco GP"), whose manager is BCLS Fund II, is the general partner of BCLS II Investco. As a result, each of BCLSI II, BCLS Fund II and BCLS II Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Investco. Each of BCLSI II, BCLS Fund II and BCLS II Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

4. Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS SB. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS SB. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

5. Boylston Coinvestors, LLC is the general partner of BCIPLS.

6. Bain Capital Life Sciences Investors, LLC ("BCLSI") (i) is the manager of BCLSI II, (ii) is the general partner of BCLSP and (iii) 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.

Remarks:

	See signatures included in Exhibit 99.1	12/05/2022
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

                                                                    Exhibit 99.1

                    List of Joint Filers and Signature Page

BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC
By: /s/ Adam Koppel
    ----------------
Title: Managing Director

BCLS SB INVESTCO, LP
By: Bain Capital Life Sciences Partners, LP, its general partner
By: Bain Capital Life Sciences Investors, LLC, its general partner
By: /s/ Adam Koppel
    -----------------
Title: Managing Director

BAIN CAPITAL LIFE SCIENCES PARTNERS, LP
By: Bain Capital Life Sciences Investors, LLC, its general partner
By: /s/ Adam Koppel
    -----------------
Title: Managing Director

BAIN CAPITAL LIFE SCIENCES FUND II, L.P.
By: Bain Capital Life Sciences Investors II, LLC, its general partner
By: Bain Capital Life Sciences Investors, LLC, its manager
By: /s/ Adam Koppel
    -----------------
Title: Managing Director

BAIN CAPITAL LIFE SCIENCES INVESTORS II, LLC
By: Bain Capital Life Sciences Investors, LLC, its manager
By: /s/ Adam Koppel
    -----------------
Title: Managing Director

BCLS II INVESTCO, LP
By: BCLS II Investco (GP), LLC, its general partner
By: Bain Capital Life Sciences Fund II, L.P., its manager
By: Bain Capital Life Sciences Investors II, LLC, its general partner
By: Bain Capital Life Sciences Investors, LLC, its manager
By: /s/ Adam Koppel
    ---------------
Title: Managing Director

BCLS II INVESTCO (GP), LLC
By: Bain Capital Life Sciences Fund II, L.P., its manager
By: Bain Capital Life Sciences Investors II, LLC, its general partner
By: Bain Capital Life Sciences Investors, LLC, its manager
By: /s/ Adam Koppel
    ----------------
Title: Managing Director

BCIP LIFE SCIENCES ASSOCIATES, LP
By: Boylston Coinvestors, LLC, its general partner
By: /s/ Adam Koppel
    ------------------
Title: Authorized Signatory