X0206 3 2021-02-03 0 0001785345 Landos Biopharma, Inc. LABP 0001224962 PERCEPTIVE ADVISORS LLC 51 ASTOR PLACE, 10TH FLOOR NEW YORK NY 10003 1 0 1 0 0001249675 PERCEPTIVE LIFE SCIENCES MASTER FUND LTD 51 ASTOR PLACE, 10TH FLOOR NEW YORK NY 10003 1 0 1 0 0001844296 Xontogeny, LLC 51 ASTOR PLACE, 10TH FLOOR NEW YORK NY 10003 1 0 1 0 0001757940 Perceptive Xontogeny Venture Fund, LP 51 ASTOR PLACE, 10TH FLOOR NEW YORK NY 10003 1 0 1 0 0001164426 EDELMAN JOSEPH 51 ASTOR PLACE, 10TH FLOOR NEW YORK NY 10003 1 0 1 0 Common Stock 3090924 I See footnote Series A Preferred Stock Common Stock 2941769 I See footnote Series A Preferred Stock Common Stock 2941769 I See footnote Series B Preferred Stock Common Stock 2857795 I See footnote Series B Preferred Stock Common Stock 2857795 I See footnote Series B Preferred Stock Common Stock 1770600 I See footnote The securities are directly held by Xontogeny, LLC ("Xontogeny"). C2 Ventures, LLC ("C2") is the manager of Perceptive XV Holdings, LLC ("Holdings"), the manager of Xontogeny. Joseph Edelman is the managing member of C2. Holdings, C2, and Mr. Edelman disclaim, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of his or its indirect pecuniary interest therein, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purposes. The securities are directly held by Perceptive Life Sciences Master Fund Ltd. (the "Master Fund"). Perceptive Advisors LLC (the "Advisor") serves as the investment manager of Master Fund. Joseph Edelman is the managing member of the Advisor. Each of Mr. Edelman and the Advisor disclaims, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of his/its indirect pecuniary interest therein, and this report shall not be deemed an admission that either Mr. Edelman or the Advisor is the beneficial owner of such securities for purposes of Section 16 or for any other purposes. The securities are directly held by Perceptive Xontogeny Ventures, L.P. ("PXV"). The Advisor serves as the investment manager of PXV, and Perceptive Xontogeny Ventures GP, LLC ("PXV GP") is the general partner of PXV. Mr. Edelman is the managing member of PXV GP and the Advisor. The Advisor, PXV GP and Mr. Edelman disclaim, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of his or its indirect pecuniary interest therein, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purposes. The securities are directly held by PX Venture (A), LLC. The Advisor serves as the investment manager of PXV, and Perceptive Xontogeny Ventures GP, LLC ("PXV GP") is the general partner of PXV. Mr. Edelman is the managing member of PXV GP and the Advisor. The Advisor, PXV GP and Mr. Edelman disclaim, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of his or its indirect pecuniary interest therein, and this report shall not be deemed an admission that they are the beneficial owner of such securities for purposes of Section 16 or for any other purposes. Each share of the Issuer's Series A preferred stock will automatically convert 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 has no expiration date. Each share of the Issuer's Series B preferred stock will automatically convert 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 has no expiration date. /s/ Joseph Edelman - for Perceptive Advisors LLC, By: Joseph Edelman, its managing member 2021-02-03 /s/ Joseph Edelman - for Perceptive Life Sciences Master Fund Ltd, By: Perceptive Advisors LLC, its investment manager, By: Joseph Edelman, its managing member 2021-02-03 /s/ Joseph Edelman - for Xontogeny LLC, By: C2 Ventures, LLC, By: Joseph Edelman, its managing member 2021-02-03 /s/ Joseph Edelman - for Perceptive Xontogeny Venture Fund L.P., By: Perceptive Xontogeny Ventures GP, LLC, its general partner, By: Joseph Edelman, its managing member 2021-02-03 /s/ Joseph Edelman 2021-02-03