SCHEDULE 13G/A 0001415889-25-011894 0001863769 XXXXXXXX LIVE 2 Common Stock, $0.0001 par value per share 09/30/2025 0001798749 JADE BIOSCIENCES, INC. 008064206 930 WINTER STREET SUITE M-500 WALTHAM MA 02451 Rule 13d-1(c) Frazier Life Sciences Public Fund, L.P. b DE 0.00 1384646.00 0.00 1384646.00 1384646.00 4.2 PN The shares listed in rows 6, 8 and 9 include shares that were acquired from Frazier Life Sciences Public Overage Fund, L.P. pursuant to a merger between Frazier Life Sciences Public Overage Fund, L.P. and Frazier Life Sciences Public Fund, L.P. The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLSP, L.P. b DE 0.00 1384646.00 0.00 1384646.00 1384646.00 4.2 PN The shares listed in rows 6, 8 and 9 include shares that were acquired from Frazier Life Sciences Public Overage Fund, L.P. pursuant to a merger between Frazier Life Sciences Public Overage Fund, L.P. and Frazier Life Sciences Public Fund, L.P. The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLSP, L.L.C. b DE 0.00 1384646.00 0.00 1384646.00 1384646.00 4.2 OO The shares listed in rows 6, 8 and 9 include shares that were acquired from Frazier Life Sciences Public Overage Fund, L.P. pursuant to a merger between Frazier Life Sciences Public Overage Fund, L.P. and Frazier Life Sciences Public Fund, L.P. The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. Frazier Life Sciences X, L.P. b DE 0.00 9488.00 0.00 9488.00 9488.00 0.0 PN The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLS X, L.P. b DE 0.00 9488.00 0.00 9488.00 9488.00 0.0 PN The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLS X, L.L.C. b DE 0.00 9488.00 0.00 9488.00 9488.00 0.0 OO The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. Frazier Life Sciences XI, L.P. b DE 0.00 19146.00 0.00 19146.00 19146.00 0.1 PN The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLS XI, L.P. b DE 0.00 19146.00 0.00 19146.00 19146.00 0.1 PN The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. FHMLS XI, L.L.C. b DE 0.00 19146.00 0.00 19146.00 19146.00 0.1 OO The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. James N. Topper b X1 0.00 9488.00 0.00 9488.00 9488.00 0.0 IN The shares listed in rows 6, 8 and 9 consist of 9,488 shares of Common Stock held directly by Frazier Life Sciences X, L.P. The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. Patrick J. Heron b X1 0.00 9488.00 0.00 9488.00 9488.00 0.0 IN The shares listed in rows 6, 8 and 9 consist of 9,488 shares of Common Stock held directly by Frazier Life Sciences X, L.P. The percentage listed in row 11 is calculated based on 32,626,730 shares of Common Stock outstanding on August 8, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 13, 2025. JADE BIOSCIENCES, INC. 930 WINTER STREET, SUITE M-500, WALTHAM, MA, 02451. The entities and persons filing this statement (collectively, the "Reporting Persons") are: Frazier Life Sciences Public Fund, L.P. ("FLSPF") FHMLSP, L.P. FHMLSP, L.L.C. Frazier Life Sciences X, L.P. ("FLS X") FHMLS X, L.P. FHMLS X, L.L.C. Frazier Life Sciences XI, L.P. ("FLS XI") FHMLS XI, L.P. FHMLS XI, L.L.C. James N. Topper ("Topper") Patrick J. Heron ("Heron" and together with Topper, the "Members") The address of the principal place of business for each of the Reporting Persons is: c/o Frazier Life Sciences Management, L.P. 1001 Page Mill Rd, Building 4, Suite B Palo Alto, CA 94304 The information contained in row 4 of each Reporting Person's cover page to this Statement is incorporated by reference. Y The information contained in row 9 of each Reporting Person's cover page to this Statement (including the footnotes thereto) is incorporated by reference. FLSPF directly holds 1,384,646 shares of Common Stock. FHMLSP, L.P. is the general partner of FLSPF and the general partner of FHMLSP, L.P. is FHMLSP, L.L.C., which is managed by an investment committee of four that acts by majority vote. Accordingly, no members of such committee are attributed beneficial ownership of the securities directly held by FLSPF. FLS X directly holds 9,488 shares of Common Stock. FHMLS X, L.P. is the general partner of FLS X and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. Heron and Topper are the members of FHMLS X, L.L.C. and therefore share voting and investment power over the shares of Common Stock held by FLS X. FLS XI directly holds 19,146 shares of Common Stock. FHMLS XI, L.P. is the general partner of FLS XI and the general partner of FHMLS XI, L.P. is FHMLS XI, L.L.C., which is managed by an investment committee of three that acts by majority vote. Accordingly, no members of such committee are attributed beneficial ownership of the securities directly held by FLS XI. Except as specifically stated herein, the filing of this Statement shall not be construed as an admission that any Reporting Person or any of the foregoing is, for the purposes of Section 13(d) and/or Section 13(g) of the Act or otherwise, the beneficial owner of any securities covered by this Statement or a member of a "group" with any other person. The information contained in row 11 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. The information contained in row 5 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. The information contained in row 6 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. The information contained in row 7 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. The information contained in row 8 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Exhibit 99.1 Joint Filing Agreement Frazier Life Sciences Public Fund, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLSP, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLSP, L.L.C. /s/ Steve R. Bailey 11/14/2025 Frazier Life Sciences X, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLS X, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLS X, L.L.C. /s/ Steve R. Bailey 11/14/2025 Frazier Life Sciences XI, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLS XI, L.P. /s/ Steve R. Bailey 11/14/2025 FHMLS XI, L.L.C. /s/ Steve R. Bailey 11/14/2025 James N. Topper /s/ Steve R. Bailey 11/14/2025 Patrick J. Heron /s/ Steve R. Bailey 11/14/2025