X0609 4 2026-10-08 0 0002139097 TRex Bio, Inc. TRXB 0001717728 SVLSF VI, LLC false 28 STATE STREET, SUITE 980 BOSTON MA 02109 0 0 1 0 0001717730 SV Life Sciences Fund VI (GP), L.P. false 28 STATE STREET, SUITE 980 BOSTON MA 02109 0 0 1 0 0001642251 SV Life Sciences Fund VI, L.P. false 28 STATE STREET, SUITE 980 BOSTON MA 02109 0 0 1 0 0 Common Stock 2026-10-08 4 P 0 89783 14.00 A 214869 I By SV Life Sciences Fund VI, L.P. Common Stock 2026-10-13 4 C 0 1574074 0 A 1788943 I By SV Life Sciences Fund VI, L.P. Common Stock 2026-10-13 4 C 0 475411 0 A 2264354 I By SV Life Sciences Fund VI, L.P. Common Stock 2026-10-08 4 P 0 3074 14.00 A 7356 I By SV Life Sciences Fund VI Strategic Partners, L.P. Common Stock 2026-10-13 4 C 0 53892 0 A 61248 I By SV Life Sciences Fund VI Strategic Partners, L.P. Common Stock 2026-10-13 4 C 0 16277 0 A 77525 I By SV Life Sciences Fund VI Strategic Partners, L.P. Common Stock 2026-10-13 4 C 0 669939 0 A 669939 I By SV Trex Coinvestment, L.P. Series A Preferred Stock 2026-10-13 4 C 0 1574074 0 D Common Stock 1574074 0 I By SV Life Sciences Fund VI, L.P. Series B Preferred Stock 2026-10-13 4 C 0 475411 0 D Common Stock 475411 0 I By SV Life Sciences Fund VI, L.P. Series A Preferred Stock 2026-10-13 4 C 0 53892 0 D Common Stock 53892 0 I By SV Life Sciences Fund VI Strategic Partners, L.P. Series B Preferred Stock 2026-10-13 4 C 0 16277 0 D Common Stock 16277 0 I By SV Life Sciences Fund VI Strategic Partners, L.P. Series B Preferred Stock 2026-10-13 4 C 0 669939 0 D Common Stock 669939 0 I By SV Trex Coinvestment, L.P. The shares are held directly by SV Life Sciences Fund VI, L.P. ("SV Fund VI"). SV Life Sciences Fund VI (GP), L.P. (the "GP LP") is the general partner of SV Fund VI, and SVLSF VI, LLC ("SVLSF") is the general partner of GP LP. Investment and voting decisions of SV Fund VI are made by the investment committee of SVLSF. Each of GP LP and SVLSF disclaims beneficial ownership except to the extent of its pecuniary interest, and this report is not an admission of beneficial ownership for any other purpose. The shares are held directly by SV Life Sciences Fund VI Strategic Partners, L.P. ("SV Strategic Partners VI"). GP LP is the general partner of SV Strategic Partners VI, and SVLSF is the general partner of GP LP. Investment and voting decisions of SV Strategic Partners VI are made by the investment committee of SVLSF. Each of GP LP and SVLSF disclaims beneficial ownership except to the extent of its pecuniary interest, and this report is not an admission of beneficial ownership for any other purpose. The shares are held directly by SV Trex Coinvestment, L.P. ("SV Coinvestment"). GP LP is the general partner of SV Coinvestment, and SVLSF is the general partner of GP LP. Investment and voting decisions of SV Coinvestment are made by the investment committee of SVLSF. Each of GP LP and SVLSF disclaims beneficial ownership and this report is not an admission of beneficial ownership for any other purpose. On October 13, 2026, 3.8649 shares of preferred stock automatically converted into one share of common stock upon the closing of the issuer's initial public offering, for no additional consideration. The preferred stock has no expiration date. Represents shares purchased by SV Fund VI in the issuer's initial public offering. Represents shares purchased by SV Strategic Partners VI in the issuer's initial public offering. SVLSF VI, LLC By: Brent M. Faduski, Officer /s/ Brent M. Faduski 2026-10-13 SV Life Sciences Fund VI (GP), L.P. By: SVLSF VI, LLC, its General Partner By: Brent M. Faduski, Officer /s/ Brent M. Faduski 2026-10-13 SV Life Sciences Fund VI, L.P. By: SV Life Sciences Fund VI (GP), L.P., its General Partner By: SVLSF VI, LLC, its General Partner By: Brent M. Faduski, Officer /s/ Brent M. Faduski 2026-10-13