X0306 4 2015-08-20 0 0001124105 CATALYST BIOSCIENCES, INC. CBIO 0001342821 Himawan Jeff 260 LITTLEFIED AVENUE SOUTH SAN FRANCISCO CA 94080 1 0 1 0 Common Stock 2015-08-20 4 J 0 1068790 A 1068790 I By Essex Woodlands Health Ventures Fund VIII, L.P. Common Stock 2015-08-20 4 J 0 77059 A 1145849 I By Essex Woodlands Health Ventures Fund VIII-A, L.P. Common Stock 2015-08-20 4 J 0 33503 A 1179352 I By Essex Woodlands Health Ventures Fund VIII-B, L.P. Warrant (Right to Buy) 33.27 2015-08-20 4 J 0 3065 A 2019-04-09 Common Stock 3065 3065 I By Essex Woodlands Health Ventures Fund VIII, L.P. Warrant (Right to Buy) 33.27 2015-08-20 4 J 0 220 A 2019-04-09 Common Stock 220 220 I By Essex Woodlands Health Ventures Fund VIII-A, L.P. Warrant (Right to Buy) 33.27 2015-08-20 4 J 0 96 A 2019-04-09 Common Stock 96 96 I By Essex Woodlands Health Ventures Fund VIII-B, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 17757 A 2020-05-29 Common Stock 17757 17757 I By Essex Woodlands Health Ventures Fund VIII, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 1280 A 2020-05-29 Common Stock 1280 1280 I By Essex Woodlands Health Ventures Fund VIII-A, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 556 A 2020-05-29 Common Stock 556 556 I By Essex Woodlands Health Ventures Fund VIII-B, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 21926 A 2010-06-29 Common Stock 21926 21926 I By Essex Woodlands Health Ventures Fund VIII, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 1580 A 2010-06-29 Common Stock 1580 1580 I By Essex Woodlands Health Ventures Fund VIII-A, L.P. Warrant (Right to Buy) 3.33 2015-08-20 4 J 0 687 A 2010-06-29 Common Stock 687 687 I By Essex Woodlands Health Ventures Fund VIII-B, L.P. Represents shares of the Issuer issued pursuant to that certain Agreement and Plan of Merger (the "Merger Agreement"), dated as of March 5, 2015 as amended on May 6 and May 13, 2015, by and among the Issuer, Talos Merger Sub, Inc. and a Delaware corporation then known as Catalyst Biosciences, Inc. ("Old Catalyst"). Pursuant to the terms of the Merger Agreement, each share of common stock of Old Catalyst was converted into 0.0382 shares of the Issuer's common stock. Essex Woodlands Health Ventures VIII, L.P. (the "Essex Funds GP"), is the general partner of each of Essex Woodlands Health Ventures Fund VIII, L.P. ("Fund VIII"), Essex Woodlands Health Ventures Fund VIII-A, L.P. ("Fund VIII-A") and Essex Woodlands Health Ventures Fund VIII-B, L.P. ("Fund VIII-B", and together with Fund VIII and Fund VIII-A, the "Essex Funds"). Essex Woodlands Health Ventures VIII, L.L.C. (the "General Partner") is the general partner of the Essex Funds GP. The General Partner holds sole voting and dispositive power over the shares held by each of the Essex Funds (the "Shares"). The managers of the General Partner are James L. Currie, Martin P. Sutter, Immanuel Thangaraj, Ron Eastman, Guido Neels, Petri Vainio, Jeff Himawan (also a member of the Issuer's board of directors), and Steve Wiggins (collectively, the "Managers"), and may exercise voting and investment control over the Shares only by the majority action of the Managers. (Continued in Footnote 3) 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 interests therein. On April 9, 2014, Reporting Person was granted a warrant to purchase 80,240 shares of the Series E Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series E Preferred Stock of Old Catalyst was convertible into 1 share of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 3,065 shares of the Catalyst's common stock at a per share exercise price of $33.27. The warrant is fully vested and exercisable. On April 9, 2014, Reporting Person was granted a warrant to purchase 5,785 shares of the Series E Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series E Preferred Stock of Old Catalyst was convertible into 1 share of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 220 shares of the Catalyst's common stock at a per share exercise price of $33.27. The warrant is fully vested and exercisable. On April 9, 2014, Reporting Person was granted a warrant to purchase 2,515 shares of the Series E Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series E Preferred Stock of Old Catalyst was convertible into 1 share of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 96 shares of the Catalyst's common stock at a per share exercise price of $33.27. The warrant is fully vested and exercisable. On May 29, 2015, Reporting Person acquired a warrant to purchase 46,848 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 17,757 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. On May 29, 2015, Reporting Person acquired a warrant to purchase 3,351 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 1,280 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. On May 29, 2015, Reporting Person acquired a warrant to purchase 1,457 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 556 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. On June 29, 2015, Reporting Person acquired a warrant to purchase 57,400 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 21,926 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. On June 29, 2015, Reporting Person acquired a warrant to purchase 4,138 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 1,580 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. On June 29, 2015, Reporting Person acquired a warrant to purchase 1,799 shares of the Series F Preferred Stock of Old Catalyst at an exercise price of $1.2706 per share. Each share of Series F Preferred Stock of Old Catalyst was convertible into 10 shares of common stock of Old Catalyst. Pursuant to the Merger Agreement, this warrant was converted into a warrant to purchase 687 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable. /s/ Nassim Usman Attorney-in-Fact for Jeff Himawan 2015-08-20