X0306 4 2018-06-22 0 0001731831 Eidos Therapeutics, Inc. EIDX 0001619841 Shah Rajeev M. C/O RA CAPITAL MANAGEMENT LLC 20 PARK PLAZA, SUITE 1200 BOSTON MA 02116 1 0 0 0 Common Stock 2018-06-22 4 C 0 1103847 A 1103847 I See footnote Common Stock 2018-06-22 4 P 0 1058824 17.00 A 2162671 I See footnote Series B Convertible Preferred Stock 2018-06-22 4 C 0 922950 0.00 D Common Stock 1103847 0 I See footnote The convertible preferred stock automatically converted to common stock immediately prior to the closing of the Issuer's initial public offering on a 1.196-for-one basis, and had no expiration date. Includes (a) 898,533 shares of Common Stock that are held by RA Capital Healthcare Fund, L.P.(the "Fund") and (b) 205,314 shares of Common Stock that are held in an account owned by a separately managed account (the "Account"). RA Capital Management, LLC (the "Adviser") is the general partner of the Fund and the investment adviser of the Account. Peter Kolchinsky is the sole manager of the Adviser, and Mr. Shah is a member of the Adviser. Mr. Shah has no pecuniary interest in the reported securities held in the Account and therefore disclaims beneficial ownership of those securities. Mr. Shah disclaims beneficial ownership of the reported securities held by the Fund except to the extent of his pecuniary interest therein. Includes (a) 856,266 shares of Common Stock held by the Fund and (b) 202,558 held in the Account, in each case acquired in the Issuer's initial public offering. These securities include 1,754,799 shares held by the Fund and 407,872 shares held in the Account. Represents 751,282 shares of Series B Convertible Preferred Stock held by the Fund and 171,668 shares of Series B Convertible Preferred Stock held in the Account. /s/ Franco Valle, Attorney-in-Fact 2018-06-22