X0206 3 2021-07-14 0 0001380106 RAPID MICRO BIOSYSTEMS, INC. RPID 0001703031 Bain Capital Life Sciences Investors, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001703030 Bain Capital Life Sciences Partners, LP 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001687968 Bain Capital Life Sciences Fund, L.P. 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001702921 BCIP Life Sciences Associates, LP 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001702957 Schwartz Jeffrey Lawrence 200 CLARENDON STREET BOSTON MA 02116 1 0 1 0 0001578965 Koppel Adam 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 Series B1 Preferred Stock Class A Common Stock 6999998 I See footnotes Series C1 Preferred Stock Class A Common Stock 1334562 I See footnotes Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock is convertible, at the option of the holder, into 0.2 of a share of the Issuer's Class A Common Stock and will automatically convert immediately prior to the closing of the Issuer's initial public offering. These securities have no expiration date. 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"). 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. 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. 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. Jeffrey Schwartz is a director of the Issuer. BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC, By: /s/ Jeffrey Schwartz, Title: Managing Director 2021-07-14 BAIN CAPITAL LIFE SCIENCES PARTNERS, LP, By: Bain Capital Life Sciences Investors, LLC, its general partner, By: /s/ Jeffrey Schwartz, Title: Managing Director 2021-07-14 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 2021-07-14 BCIP LIFE SCIENCES ASSOCIATES, LP, By: Boylston Coinvestors, LLC, its general partner, By: /s/ Jeffrey Schwartz, Title: Authorized Signatory 2021-07-14 /s/ Jeffrey Schwartz 2021-07-14 /s/ Adam Koppel 2021-07-14