X0609 4 2026-08-10 0002056611 Latigo Biotherapeutics, Inc. LTGO 0001581754 Tananbaum James B. false C/O LATIGO BIOTHERAPEUTICS, INC. 1300 RANCHO CONEJO BLVD., SUITE 305 THOUSAND OAKS CA 91320 true false true false 0 Common Stock 2026-08-10 4 C 0 3117664 A 3117664 I See footnote Common Stock 2026-08-10 4 C 0 445320 A 3562984 I See footnote Common Stock 2026-08-10 4 C 0 1125823 A 1125823 I See footnote Common Stock 2026-08-10 4 C 0 742201 A 1868024 I See footnote Common Stock 2026-08-10 4 P 0 140000 18 A 2008024 I See footnote Common Stock 2026-08-10 4 C 0 195776 A 2203800 I See footnote Common Stock 2026-08-10 4 C 0 3117664 A 3117664 I See footnote Common Stock 2026-08-10 4 C 0 296880 A 3414544 I See footnote Series A-2 Convertible Stock 2026-08-10 4 C 0 3117664 D Common Stock 3117664 0 I See footnote Series B Convertible Preferred Stock 2026-08-10 4 C 0 445320 D Common Stock 445320 0 I See footnote Series A-2 Convertible Preferred Stock 2026-08-10 4 C 0 1125823 D Common Stock 1125823 0 I See footnote Series B Convertible Preferred Stock 2026-08-10 4 C 0 742201 D Common Stock 742201 0 I See footnote Series A-2 Convertible Preferred Stock 2026-08-10 4 C 0 3117664 D Common Stock 3117664 0 I See footnote Series B Convertible Preferred Stock 2026-08-10 4 C 0 296880 D Common Stock 296880 0 I See footnote Convertible Promissory Note 2026-08-10 4 C 0 195776 D Common Stock 195776 0 I See footnote Each share of preferred stock converted automatically into 1 share of common stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The preferred stock had no expiration date. The securities are held of record by Foresite Capital Fund V, L.P. (Fund V). Foresite Capital Management V, LLC (FCM V) is the general partner of Fund V and may be deemed to have sole voting and dispositive power over the securities held by Fund V. The Reporting Person is the sole managing member of FCM V and may be deemed to have sole voting and dispositive power over the securities held by Fund V. Each of Fund V, FCM V and the Reporting Person disclaims the existence of a "group" and disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. The securities are held of record by Foresite Capital Fund VI, LP (Fund VI). Foresite Capital Management VI, LLC (FCM VI) is the general partner of Fund VI and may be deemed to have sole voting and dispositive power over the securities held by Fund VI. The Reporting Person is the sole managing member of FCM VI and may be deemed to have sole voting and dispositive power over the securities held by Fund VI. Each of Fund VI, FCM VI and the Reporting Person disclaims the existence of a "group" and disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Reflects a convertible note that is convertible into shares of Common Stock of the Issuer. The convertible note has a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. The securities are held of record by Foresite Capital Opportunity Fund V, L.P. (Opportunity Fund V). Foresite Capital Opportunity Management V, LLC (FCOM V) is the general partner of Opportunity Fund V and may be deemed to have sole voting and dispositive power over the shares held by Opportunity Fund V. The Reporting Person is the sole managing member of FCOM V and may be deemed to have sole voting and dispositive power over the securities held by Opportunity Fund V. Each of Opportunity Fund V, FCOM V and the Reporting Person disclaims the existence of a "group" and disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. /s/ Sabrina Nieder, Attorney-in-Fact 2026-08-10