X0306 4 2021-02-08 0 0001785345 Landos Biopharma, Inc. LABP 0001678736 Poukalov Konstantin C/O LANDOS BIOPHARMA, INC. 1800 KRAFT DRIVE, SUITE 216 BLACKSBURG VA 24060 1 0 1 0 Common Stock 2021-02-08 4 C 0 13369728 A 13369728 I By funds Common Stock 2021-02-08 4 P 0 1250000 16.00 A 14619728 I By funds Series A Preferred Stock 2021-02-08 4 C 0 5883538 D Common Stock 5883538 0 I By funds Series B Preferred Stock 2021-02-08 4 C 0 7486190 D Common Stock 7486190 0 I By funds Each share of the Issuer's Series A preferred stock automatically converted into 1.8249 shares of the Issuer's common stock immediately upon the closing of the Issuer's initial public offering. The Series A preferred stock had no expiration date. Each share of the Issuer's Series B preferred stock automatically converted into 1.8249 shares of the Issuer's common stock immediately upon the closing of the Issuer's initial public offering. The Series B preferred stock had no expiration date. Consists of 5,799,564 shares of common stock held by Perceptive Life Sciences Master Fund, Ltd. ("PLSMF"), 5,799,564 shares of common stock held by Perceptive Xontogeny Venture Fund, LP ("PXVF"), and 1,770,600 shares of common stock held by PX Venture (A), LLC ("PXV"). Perceptive Advisors, LLC ("Perceptive Advisors") serves as the investment manager to PLSMF, PXVF, and PXV. The Reporting Person is a managing director of Perceptive Advisors. The Reporting Person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. Securities are held by PLSMF, PXVF, and PXV. Perceptive Advisors serves as the investment manager to Perceptive PLSMF, PXVF, and PXV and as a result may be deemed to have beneficial ownership over such securities. The Reporting Person is a Managing Director of Perceptive Advisors and may be deemed to indirectly beneficially own the securities. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein. Securities are held by PLSMF and PXVF. Perceptive Advisors serves as the investment manager to PLSMF and PXVF. and as a result may be deemed to have beneficial ownership over such securities. The Reporting Person is a Managing Director of Perceptive Advisors and may be deemed to indirectly beneficially own the securities. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein. Consists of 2,941,769 shares of common stock issuable upon conversion of Series A preferred stock held by PLSMF and 2,941,769 shares of common stock issuable upon conversion of Series A preferred stock held by PXVF. Perceptive Advisors serves as the investment manager to PLSMF and PXVF. The Reporting Person is a managing director of Perceptive Advisors. The Reporting Person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. Consists of 2,857,795 shares of common stock issuable upon conversion of Series B preferred stock held by PLSMF, 2,857,795 shares of common stock issuable upon conversion of Series B preferred stock held by PXVF and 1,770,600 shares of common stock issuable upon conversion of Series B preferred stock held by PXV. Perceptive Advisors serves as the investment manager to PLSMF, PXVF, and PXV. The Reporting Person is a managing director of Perceptive Advisors. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein. /s/ Eric W. Blanchard, Attorney-in-Fact 2021-02-08