SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* LAWLOR AUGUSTINE (Last) (First) (Middle) 47 THORNDIKE STREET SUITE B1-1 (Street) CAMBRIDGE MA 02141 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol CATALYST BIOSCIENCES, INC. [ CBIO ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 08/20/2015
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/20/2015		J(1)		1,041,024	A	(1)	1,041,024	I	By HealthCare Ventures VIII, L.P.(2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Warrant (Right to Buy)	$33.27	08/20/2015		J(3)		2,254		(3)	04/09/2019	Common Stock	2,254	(3)	2,254	I	By HealthCare Ventures VIII, L.P.(2)
Warrant (Right to Buy)	$3.33	08/20/2015		J(4)		11,383		(4)	05/29/2020	Common Stock	11,383	(4)	11,383	I	By HealthCare Ventures VIII, L.P.(2)
Warrant (Right to Buy)	$3.33	08/20/2015		J(5)		14,056		(5)	06/29/2020	Common Stock	14,056	(5)	14,056	I	By HealthCare Ventures VIII, L.P.(2)

Explanation of Responses:

1. 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.

2. 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.

3. On April 9, 2014, HCVVIII acquired a warrant to purchase 59,027 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 2,254 shares of the Catalyst's common stock at a per share exercise price of $33.27. The warrant is fully vested and exercisable.

4. On May 29, 2015, HCVVIII acquired a warrant to purchase 29,800 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 11,383 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable.

5. On June 29, 2015, HCVVIII acquired a warrant to purchase 36,796 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 14,056 shares of the Catalyst's common stock at a per share exercise price of $3.33. The warrant is fully vested and exercisable.

Remarks:

	/s/ Nassim Usman Attorney-in-Fact for Augustine Lawlor	08/20/2015
	** Signature of Reporting Person	Date
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