X0306 4 2021-05-11 0 0001827506 Talaris Therapeutics, Inc. TALS 0001713663 Longitude Capital Partners III, LLC C/O LONGITUDE CAPITAL PARTNERS III, LLC 2740 SAND HILL ROAD, 2ND FLOOR MENLO PARK CA 94025 0 0 1 0 0001674099 Longitude Venture Partners III, L.P. 2740 SAND HILL ROAD, 2ND FLOOR MENLO PARK CA 94025 0 0 1 0 0001253886 ENRIGHT PATRICK G 2740 SAND HILL ROAD, 2ND FLOOR MENLO PARK CA 94025 0 0 1 0 0001431159 Tammenoms Bakker Juliet 2740 SAND HILL ROAD, 2ND FLOOR MENLO PARK CA 94025 0 0 1 0 Common Stock 2021-05-11 4 C 0 2985775 A 2985775 I By Longitude Venture Partners III, L.P. Common Stock 2021-05-11 4 P 0 235000 17.00 A 3220775 I By Longitude Venture Partners III, L.P. Series A Preferred Stock 2021-05-11 4 C 0 1308410 0.00 D Common Stock 1308410 0 I By Longitude Venture Partners III, L.P. Series A-1 Preferred Stock 2021-05-11 4 C 0 1271027 0.00 D Common Stock 1271027 0 I By Longitude Venture Partners III, L.P. Series B Preferred Stock 2021-05-11 4 C 0 406338 0.00 D Common Stock 406338 0 I By Longitude Venture Partners III, L.P. Each share of Series A Preferred Stock converted into common stock on a 1-for-5.35 basis automatically upon the closing of the Issuer's initial public offering. Each share of Series A-1 Preferred Stock converted into common stock on a 1-for-5.35 basis automatically upon the closing of the Issuer's initial public offering. Each share of Series B Preferred Stock converted into common stock on a 1-for-5.35 basis automatically upon the closing of the Issuer's initial public offering. The Series A Preferred Stock, Series A-1 Preferred Stock and Series B Preferred Stock had no expiration date. These shares are held by Longitude Venture Partners III, L.P ("LVP III"). Longitude Capital Partners III, LLC ("LCP III") is the general partner of LVP III and may be deemed to have voting and investment power over the shares held by LVP III. Patrick G. Enright and Juliet Tammenoms Bakker are managing members of LCP III and may be deemed to share voting and investment power with respect to the shares held by LVP III. Each of LCP III, Mr. Enright and Ms. Tammenoms Bakker disclaims beneficial ownership of such shares and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein. On May 11, 2021, LVP III purchased 235,000 shares of Common Stock of the Issuer at a price of $17.00 per share pursuant to an underwritten public offering. /s/ Patrick G. Enright, individually, and as Managing Member of Longitude Capital Partners III, LLC and as Managing Member of Longitude Capital Partners III, LLC., General Partner of Longitude Venture Partners III, L.P. 2021-05-11 /s/ Juliet Tammenoms Bakker 2021-05-11