<SEC-DOCUMENT>0001193125-18-037083.txt : 20180209
<SEC-HEADER>0001193125-18-037083.hdr.sgml : 20180209
<ACCEPTANCE-DATETIME>20180209080033
ACCESSION NUMBER:		0001193125-18-037083
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20180209
ITEM INFORMATION:		Other Events
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20180209
DATE AS OF CHANGE:		20180209

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CATALYST BIOSCIENCES, INC.
		CENTRAL INDEX KEY:			0001124105
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				562020050
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51173
		FILM NUMBER:		18587798

	BUSINESS ADDRESS:	
		STREET 1:		260 LITTLEFIELD AVENUE
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		6507450655

	MAIL ADDRESS:	
		STREET 1:		260 LITTLEFIELD AVENUE
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TARGACEPT INC
		DATE OF NAME CHANGE:	20000919
</SEC-HEADER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>d536030d8k.htm
<DESCRIPTION>8-K
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<HTML><HEAD>
<TITLE>8-K</TITLE>
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 <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT
STYLE="white-space:nowrap">8-K</FONT></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:14pt; font-family:Times New Roman" ALIGN="center"><B>CURRENT
REPORT </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Pursuant to Section&nbsp;13 or 15(d) </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>of the Securities Exchange Act of 1934 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Date of Report (Date of earliest event reported): February&nbsp;9, 2018 </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>CATALYST BIOSCIENCES, INC. </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact name of registrant as specified in its charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top" ALIGN="center"><B>Delaware</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">000-51173</FONT></B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">56-2020050</FONT></B></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>of incorporation)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Commission</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>File Number)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(IRS Employer</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification No.)</B></P></TD></TR>
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<TD VALIGN="top" COLSPAN="3" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>260 Littlefield Ave.</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>South San Francisco, California</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center"><B>94080</B></TD></TR>
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<TD VALIGN="top" COLSPAN="3" ALIGN="center"><B>(Address of principal executive offices)</B></TD>
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<TD VALIGN="top" ALIGN="center"><B>(Zip Code)</B></TD></TR>
</TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(650) 871&#150;0761 </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Registrant&#146;s telephone number, including area code </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Check the appropriate box below
if the Form <FONT STYLE="white-space:nowrap">8-K</FONT> filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: </P>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top">Soliciting material pursuant to Rule <FONT STYLE="white-space:nowrap">14a-12</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.14a-12)</FONT></TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT STYLE="white-space:nowrap">14d-2(b)</FONT> under the Exchange Act (17 CFR
<FONT STYLE="white-space:nowrap">240.14d-2(b))</FONT></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT STYLE="white-space:nowrap">13e-4(c)</FONT> under the Exchange Act (17 CFR
<FONT STYLE="white-space:nowrap">240.13e-4(c))</FONT></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether the registrant is an emerging growth company as defined
in Rule 405 of the Securities Act of 1933 (&#167; 230.405 of this chapter) or Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Securities Exchange Act of 1934 (&#167; <FONT STYLE="white-space:nowrap">240.12b-2</FONT> of this chapter). </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Emerging growth company&nbsp;&nbsp;&#9746; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging
growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section&nbsp;13(a) of the Exchange
Act.&nbsp;&nbsp;&#9746; </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>

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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;8.01</B></TD>
<TD ALIGN="left" VALIGN="top"><B>Other Events </B></TD></TR></TABLE> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On February&nbsp;9, 2018, Catalyst Biosciences, Inc. issued a press release announcing <FONT
STYLE="white-space:nowrap">top-line</FONT> data from its Phase 1/2 study of subcutaneous CB 2679d/ISU304 in individuals with Hemophilia B. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">A copy of the
press release announcing the <FONT STYLE="white-space:nowrap">top-line</FONT> data from the Phase 1/2 study is attached hereto as Exhibit 99.1 and is incorporated herein by reference. </P>
<P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;9.01</B></TD>
<TD ALIGN="left" VALIGN="top"><B>Financial Statements and Exhibits. </B></TD></TR></TABLE> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(d) Exhibits. </P>
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<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Exhibit</B><br><B>No.</B></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" NOWRAP STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman"><B>Description</B></P></TD></TR>


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<TD VALIGN="top" NOWRAP>99.1</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top"><A HREF="d536030dex991.htm">Press release of Catalyst Biosciences, Inc. dated February&nbsp;9, 2018. </A></TD></TR>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURES </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned
hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top" COLSPAN="3"><B>CATALYST BIOSCIENCES, INC.</B></TD></TR>
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<TD VALIGN="top">Date: February&nbsp;9, 2018</TD>
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<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Fletcher Payne</P></TD></TR>
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<TD VALIGN="top" COLSPAN="3">Fletcher Payne</TD></TR>
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<TD VALIGN="top" COLSPAN="3">Chief Financial Officer</TD></TR>
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<DOCUMENT>
<TYPE>EX-99.1
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Exhibit 99.1 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Catalyst Biosciences Announces Positive <FONT STYLE="white-space:nowrap">Top-Line</FONT> Data from Phase 1/2 Study of </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Subcutaneous CB 2679d/ISU304 in Individuals with Hemophilia B </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>All individuals with severe hemophilia improved to mild hemophilia activity levels after only six </I></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>daily doses with a continuous linear increase in Factor IX clotting activity </I></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>These results suggest that long-term dosing of SQ CB 2679d has the potential to maintain stable </I></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>clotting activity in the high-mild hemophilia to normal range </I></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><I>Conference call and webcast to be held today, February&nbsp;9, 2018, at 8:30 a.m. EST </I></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>SOUTH SAN FRANCISCO, Calif. &#150; Feb. 9, 2018</B> &#150; Catalyst Biosciences, Inc. (NASDAQ: CBIO), a clinical-stage biopharmaceutical company focused on
developing novel medicines to address hematology indications, today announced <FONT STYLE="white-space:nowrap">top-line</FONT> data from its Phase 1/2 study of subcutaneous (SQ) prophylactic candidate CB 2679d/ISU304 being developed for the
treatment of hemophilia B in an oral presentation at the 11<SUP STYLE="font-size:85%; vertical-align:top">th</SUP> Annual Congress of The European Association for Haemophilia and Allied Disorders (EAHAD) in Madrid. Results from the trial showed a
continuous linear increase in Factor IX (FIX) activity levels following daily dosing of CB 2679d for six days. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">&#147;These exciting results demonstrate
for the first time the feasibility of a subcutaneous FIX injection to provide meaningful protection from bleeding, even after only six doses,&#148; said Dr.&nbsp;John Pasi, professor of haemostasis and thrombosis at Barts and The London School of
Medicine and Dentistry. &#147;As a result, this treatment option has the potential to normalize coagulation activity and dramatically improve the quality of life of individuals affected by hemophilia B.&#148; </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Howard Levy, chief medical officer of Catalyst, presented results from the fifth cohort of the Phase 1/2 trial of CB 2679d in patients with severe
hemophilia B. After six days of once-daily SQ dosing, CB 2679d increased FIX activity levels in 5 patients who were each dosed daily with 140 IU/kg SQ, from very low levels after washout of prior therapy to a median FIX activity level of 16% (range <FONT
STYLE="white-space:nowrap">11.5-18%),</FONT> that is well into the mild hemophilia range <FONT STYLE="white-space:nowrap">(5-40%),</FONT> and is higher than a level required to prevent hemarthrosis. The observed increase in FIX activity levels after
the daily dosing was linear, indicating that continued SQ dosing may achieve high-mild hemophilia or even normal FIX clotting activity. Terminal SQ half-life was 63.2 hours (interquartile range <FONT STYLE="white-space:nowrap">60.2-64</FONT> hours)
with the result that activity levels were still <FONT STYLE="white-space:nowrap">4-6.4%,</FONT> 5 days after the last dose. No inhibitors to CB 2679d or FIX were induced to date. One subject had moderate adverse events of pain, erythema and redness
after the first 2 injections and mild rating after subsequent injections. Other subjects in cohort 5 reported some of these adverse events, mainly with initial injections. Two subjects had bruising after injection when FIX activity levels were low
that did not occur with subsequent injections as FIX activity levels rose. Presentation materials can be accessed at: <U>http://ir.catalystbiosciences.com/phoenix.zhtml?c=254141&amp;p=irol-calendar</U>. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Levy remarked, &#147;Existing IV therapies have FIX trough levels that can drop as low as <FONT STYLE="white-space:nowrap">1-3%</FONT> before repeat
dosing. Daily subcutaneous dosing of CB 2679d has the potential to minimize the variability in FIX activity levels observed between IV doses and maintain individuals in the mild or even normal hemophilia range. This study demonstrates that, even
after just six days of treatment, CB 2679d compares favorably to currently approved therapies for hemophilia B, all of which are infused IV.&#148; </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Conference Call and Webcast </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The management team will host a conference call with slides for investors today, Friday Feb. 9, 2018, at 8:30 a.m. EST to discuss the data and answer
questions.&nbsp;Conference call, webcast and post-conference call replay details are as follows: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Domestic: +1.800.239.9838 </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">International: +1.323.794.2551</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Conference ID: 8902500 </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Webcast: <U>http://public.viavid.com/index.php?id=128119</U> </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Replay will be available two hours after completion of the call through Feb. 23: </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Domestic: +1.844.512.2921 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">International: +1.412.317.6671 </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Replay ID: 8902500 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The call will also be archived on the
Company&#146;s website for 30 days at <U>www.catalystbiosciences.com</U>. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>About the FIX Phase 1/2 Trial </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CB 2679d is designed as a <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">best-in-class</FONT></FONT> high potency recombinant Factor IX
product. The Phase 1/2 clinical trial of CB 2679d in patients with severe hemophilia B was conducted at three centers in South Korea by the Company&#146;s collaborator, ISU Abxis, which uses ISU304 as an alternate product name. The trial measured
the potency, subcutaneous bioavailability, half-life and clotting ability of CB 2679d achieved after single intravenous and subcutaneous dosing in the first three cohorts, followed by daily subcutaneous injections of CB 2679d in the fifth cohort.
Catalyst believes that CB 2679d may provide a subcutaneous prophylactic treatment for individuals with hemophilia B by achieving high-mild hemophilia or normal clotting activity levels in blood. CB 2679d was awarded orphan drug designations by the
European Commission in June 2017 and by the U.S. Food and Drug Administration (FDA) in September 2017. Future studies with CB 2679d are planned, with the goal of evaluating greater duration of daily dosing at lower dose and less frequent dosing.
</P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>About Hemophilia </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Hemophilia, for which there is no
cure, is a rare but serious bleeding disorder that results from a genetic or an acquired deficiency of a protein required for normal blood coagulation. The severity of the disease is defined according to the percentage of normal factor activity in
blood <FONT STYLE="white-space:nowrap">(50-150%).</FONT> According to the definitions of the World Federation of Hemophilia, patients with severe disease have factor levels &lt;1%, those with moderate disease have factor levels of <FONT
STYLE="white-space:nowrap">1-5%</FONT> and those with mild disease have factor levels of <FONT STYLE="white-space:nowrap">5%-40%.</FONT> According to the World Federation of Hemophilia, individuals with severe hemophilia bleed spontaneously and
frequently, as often as one to two times per week, those with moderate hemophilia bleed about once per month but rarely spontaneously, and those with mild hemophilia bleed rarely and some may never have a bleeding problem unless they have surgery or
a trauma. </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>About Catalyst Biosciences </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Catalyst is a clinical-stage biopharmaceutical company developing novel medicines to address hematology indications. Catalyst is focused on the field of
hemostasis, including the subcutaneous prophylaxis of hemophilia and facilitating surgery in individuals with hemophilia. For more information, please visit www.catalystbiosciences.com. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Forward-Looking Statements </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">This press release contains
forward-looking statements that involve substantial risks and uncertainties. All statements, other than statement of historical facts, included in this press release regarding our strategy, the potential uses and benefits of CB 2679d and development
plans for this product candidate are forward-looking statements. Examples of such statements include, but are not limited to, the potential for subcutaneous dosing of CB2679d to maintain clotting activity in the high-mild hemophilia to normal range.
Actual results or events could differ materially from the plans and expectations and projections disclosed in these forward-looking statements. Various important factors could cause actual results or events to differ materially from the
forward-looking statements that Catalyst makes, including, but not limited to, the risk that subsequent clinical trials will not replicate the results from initial clinical studies with small numbers of patients, that multiple subcutaneous dosing of
CB 2679d may result in potential adverse effects, including the generation of neutralizing antibodies (inhibitors), the risk that costs required to develop or manufacture Catalyst&#146;s products will be higher than anticipated, competition, and
other factors described in the &#147;Risk Factors&#148; section of the Company&#146;s most recent Quarterly Report on Form <FONT STYLE="white-space:nowrap">10-Q</FONT> filed with the SEC on November&nbsp;2, 2017. Catalyst does not assume any
obligation to update any forward-looking statements, except as required by law. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Contacts:&nbsp;&nbsp;&nbsp;&nbsp; </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Investors:&nbsp;&nbsp;&nbsp;&nbsp; </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Fletcher Payne,
CFO&nbsp;&nbsp;&nbsp;&nbsp; </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Catalyst Biosciences, Inc.&nbsp;&nbsp;&nbsp;&nbsp; </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1.650.871.0761&nbsp;&nbsp;&nbsp;&nbsp; </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>investors@catbio.com
</U></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Media: </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Josephine Belluardo, Ph.D. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">LifeSci Public Relations </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1.646.751.4361 </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>jo@lifescipublicrelations.com </U></P>
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