SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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. Issuer Name and Ticker or Trading Symbol RAPID MICRO BIOSYSTEMS, INC. [ RPID ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 07/19/2021
	4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	07/19/2021		C		6,999,998	A	(1)	6,999,998	I	See footnotes(2)(5)(6)(7)
Class A Common Stock	07/19/2021		C		1,334,562	A	(1)	8,334,560	I	See footnotes(3)(5)(6)(7)
Class A Common Stock	07/19/2021		P		100,000	A	$20	8,434,560	I	See footnotes(4)(5)(6)(7)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series B1 Preferred Stock	(1)	07/19/2021		C			35,000,001	(1)	(1)	Class A Common Stock	6,999,998	(1)	0	I	See footnotes(2)(5)(6)(7)
Series C1 Preferred Stock	(1)	07/19/2021		C			6,672,819	(1)	(1)	Class A Common Stock	1,334,562	(1)	0	I	See footnotes(3)(5)(6)(7)

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* 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, L.P. (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)

1. Name and Address of Reporting Person* Schwartz Jeffrey Lawrence (Last) (First) (Middle) C/O BAIN CAPITAL LIFE SCIENCES INVESTORS LLC, 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* Koppel Adam (Last) (First) (Middle) 200 CLARENDON STREET (Street) BOSTON MA 02116 (City) (State) (Zip)

Explanation of Responses:

1. Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

2. Represents 31,750,072 shares of the Issuer's Series B1 Preferred Stock held by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 3,249,929 shares of the Issuer's Series B1 Preferred Stock held by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities"), which were automatically converted into 6,350,013 and 649,985 shares of the Issuer's Class A Common Stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

3. Represents 6,053,214 shares of the Issuer's Series C1 Preferred Stock held by BCLS and 619,605 shares of the Issuer's Series C1 Preferred Stock held by BCIPLS, which were automatically converted into 1,210,642 and 123,920 shares of the Issuer's Class A Common stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

4. Represents 90,714 and 9,286 shares of the Issuer's Class A Common Stock purchased by BCLS and BCIPLS, respectively, in the Issuer's initial public offering.

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

6. Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

7. Jeffrey Schwartz is a director of the Issuer.

Remarks:

	BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC, By: /s/ Jeffrey Schwartz, Title: Managing Director	07/21/2021
	BAIN CAPITAL LIFE SCIENCES PARTNERS, LP, By: Bain Capital Life Sciences Investors, LLC, its general partner, By: /s/ Jeffrey Schwartz, Title: Managing Director	07/21/2021
	BAIN CAPITAL LIFE SCIENCES FUND, L.P., By: Bain Capital Life Sciences Partners, LP, its general partner, By: Bain Capital Life Sciences Investors, LLC, its general partner, By: /s/ Jeffrey Schwartz, Title: Managing Director	07/21/2021
	BCIP LIFE SCIENCES ASSOCIATES, LP, By: Boylston Coinvestors, LLC, its general partner, By: /s/ Jeffrey Schwartz, Title: Authorized Signatory	07/21/2021
	/s/ Jeffrey Schwartz	07/21/2021
	/s/ Adam Koppel	07/21/2021
	** Signature of Reporting Person	Date
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