X0306 4 2019-04-01 0 0001124105 CATALYST BIOSCIENCES, INC. CBIO 0001262327 LAWLOR AUGUSTINE 55 CAMBRIDGE PARKWAY SUITE 301 CAMBRIDGE MA 02142 1 0 0 0 Common Stock 2019-04-01 4 A 0 2414 0.00 A 5146 D Common Stock 69401 I By HealthCare Ventures VIII, L.P Represents shares of stock received in lieu of fees. HealthCare Ventures VIII, L.P. ("HCVVIII") is the registered owner of the securities. The Reporting Person is a managing director of HealthCare Partners VIII, LLC ("HCPVIII LLC"), the General Partner of HealthCare Partners VIII, L.P. ("HCPVIII"). HCPVIII is the General Partner of HCVVIII. The Reporting Person shares voting and investment power over the shares held by HCVVIII with each of Christopher Mirabelli, James Cavanaugh, John Littlechild and Harold Werner as managing directors of HCPVIII LLC. The Reporting Person disclaims beneficial ownership of those securities in which he does not have a pecuniary interest and this report shall not be deemed an admission that he is the beneficial owner of these securities for purposes of Section 16, except to the extent of his pecuniary interest therein. /s/ Nassim Usman, Attorney-in-Fact for Augustine Lawlor 2019-04-02