X0206 3 2023-12-29 0 0001936258 NewAmsterdam Pharma Co N.V. NAMS 0001703031 Bain Capital Life Sciences Investors, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001952107 BCLS Fund III Investments, LP 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001952106 Bain Capital Life Sciences III General Partner, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001875273 Bain Capital Life Sciences Fund III, L.P. 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001952080 BCLS Fund III Investments GP, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001818893 BCLS II Investco, LP 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001819101 BCLS II Investco (GP), LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001773187 Bain Capital Life Sciences Fund II, L.P. 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001796155 Bain Capital Life Sciences Investors II, LLC 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 Ordinary Shares 10473913 I See footnotes Warrant (right to buy) 11.50 2022-12-22 2027-11-23 Ordinary Shares 100000 I See footnotes Represents 5,376,356 Ordinary Shares held directly by BCLS Fund III Investments, LP ("BCLS Fund III"), 4,797,557 Ordinary Shares held directly by BCLS II Investco, LP ("BCLS II Investco"), 267,429 Ordinary Shares held directly by Bain Capital Life Sciences Fund II, L.P. ("BCLS Fund II") and 32,571 Ordinary Shares held directly by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS Fund III, BCLS II Investco and BCLS Fund II, the "Bain Capital Life Sciences Entities"). Represents a warrant to purchase 89,143 Ordinary Shares held directly by BCLS Fund II and a warrant to purchase 10,857 Ordinary Shares held directly by BCIPLS. Bain Capital Life Sciences III General Partner LLC ("BCLS III GP") is the general partner of Bain Capital Life Sciences Fund III, L.P. ("BCLS III"), which is the managing member of BCLS Fund III Investments GP, LLC ("BCLS Fund III GP"), which is the general partner of BCLS Fund III. As a result, each of BCLS III GP, BCLS III and BCLS Fund III GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund III. Each of BCLS III GP, BCLS III and BCLS Fund III GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. 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. BCLS II Investco (GP), LLC ("BCLS II Investco GP"), whose managing member 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. Boylston Coinvestors, LLC is the general partner of BCIPLS. Bain Capital Life Sciences Investors, LLC ("BCLSI") is the manager of each of BCLS III GP and BCLSI II 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. See signatures included in Exhibit 99.1 2023-12-29