X0609 4 2026-04-20 0002096997 Kailera Therapeutics, Inc. KLRA 0001703031 Bain Capital Life Sciences Investors, LLC false 200 CLARENDON STREET BOSTON MA 02116 false false true false 0001996931 Bain Capital Life Sciences IV General Partner, LLC false 200 CLARENDON STREET BOSTON MA 02116 false false true false 0001996979 Bain Capital Life Sciences Fund IV, L.P. false 200 CLARENDON STREET BOSTON MA 02116 false false true false 0002015967 BCLS Fund IV Investments GP, LLC false 200 CLARENDON STREET BOSTON MA 02116 false false true false 0002015454 BCLS Fund IV Investments, L.P. false 200 CLARENDON STREET BOSTON MA 02116 false false true false false Common Stock 2026-04-20 4 C false 16875000 A 16875000 I See footnotes Common Stock 2026-04-20 4 C false 4145768 A 21020768 I See footnotes Common Stock 2026-04-20 4 P false 1562500 16.00 A 22583268 I See footnotes Series A-1 Preferred Stock 2026-04-20 4 C false 16875000 0 D Common Stock 16875000 0 I See footnotes Series B Preferred Stock 2026-04-20 4 C false 4145768 0 D Common Stock 4145768 0 I See footnotes Each share of the Issuer's Series A-1 Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date. Each share of the Issuer's Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date. Represents securities held directly by BCLS Fund IV Investments, LP ("BCLS Fund IV Investments"). Bain Capital Life Sciences Investors, LLC ("BCLSI") is the manager of Bain Capital Life Sciences IV General Partner, LLC ("BCLS Fund IV GP"), which is the general partner of Bain Capital Life Sciences Fund IV, L.P. ("BCLS Fund IV"), which is the managing member of BCLS Fund IV Investments GP, LLC ("BCLS Fund IV Investments GP"), which is the general partner of BCLS Fund IV Investments. As a result, each of BCLSI, BCLS Fund IV GP, BCLS Fund IV and BCLS Fund IV Investments GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund IV Investments. BCLSI, BCLS Fund IV GP, BCLS Fund IV and BCLS Fund IV Investments GP each disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. See signatures included in Exhibit 99.1 2026-04-20