X0306 4 2022-02-11 0 0001626199 ALPINE IMMUNE SCIENCES, INC. ALPN 0001655827 Frazier Life Sciences VIII, L.P. C/O FRAZIER HEALTHCARE PARTNERS 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001698755 FHM LIFE SCIENCES VIII, L.P. C/O FRAZIER HEALTHCARE PARTNERS 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001698823 FHM LIFE SCIENCES VIII, L.L.C. C/O FRAZIER HEALTHCARE PARTNERS 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001365617 Heron Patrick J C/O FRAZIER HEALTHCARE PARTNERS 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001341382 Topper James N C/O FRAZIER HEALTHCARE PARTNERS 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 1 0 1 0 Common Stock 2022-02-11 4 P 0 112665 7.1006 A 1484115 D The reportable securities are held directly by Frazier Life Sciences VIII, L.P. ("FLS LP"). FHM Life Sciences VIII, L.P. ("FHM LP") is the general partner of FLS LP. FHM Life Sciences VIII, L.L.C. ("FHM LLC") is the general partner of FHM LP. James N. Topper and Patrick J. Heron are the sole managing members of FHM LLC. Mr. Topper, Mr. Heron, FHM LP and FHM LLC disclaims beneficial ownership of the securities held by FLS LP except, to the extent of his or its pecuniary interest therein, if any. Frazier Life Sciences VIII, L.P. By: FHM Life Sciences VIII, L.P., its general partner, By FHM Life Sciences VIII, L.L.C., its general partner, By: /s/ Steve Bailey, Chief Financial Officer 2022-02-15 FHM Life Sciences VIII, L.P. By: FHM Life Sciences VIII, L.L.C., its general partner, By: /s/ Steve Bailey, Chief Financial Officer 2022-02-15 FHM Life Sciences VIII, L.L.C. By: /s/ Steve Bailey, Chief Financial Officer 2022-02-15 /s/ Steve Bailey, Attorney-in-Fact for Patrick J. Heron 2022-02-15 /s/ Steve Bailey, Attorney-in-Fact for James N. Topper 2022-02-15