Catalyst Biosciences to Present Multi-Dose Subcutaneous Data for CB 2679d in Individuals with Hemophilia B in an Oral Presentation at the 11th Annual Congress of EAHAD

Pharmacokinetics and activity after daily dosing with high potency FIX variant will be reported

Conference call and webcast for investment community to be held Feb. 9, 2018 at 8:30 a.m. EST

SOUTH SAN FRANCISCO, Calif., Jan. 31, 2018 -- Catalyst Biosciences, Inc. (NASDAQ:CBIO), a clinical-stage biopharmaceutical company focused on developing novel medicines to address hematology indications, today announced an oral presentation of top-line data from the Phase 1/2 trial of subcutaneous (SQ) Factor IX candidate CB 2679d/ISU304 at the 11^th Annual Congress of The European Association for Haemophilia and Allied Disorders (EAHAD) being held Feb. 7-9 in Madrid.

Oral presentation Details
Presentation Title:                  Phase 1/2 Trial of Subcutaneously Administered Factor IX Variant CB2679d/ISU304: Pharmacokinetics and Activity
Presenter:                               Howard Levy, M.B.B.Ch., Ph.D., M.M.M.
Session:                                  Session 6
Date/Time:                              Friday, Feb. 9, at 9:00 a.m. CET
Location:                                 Palacio Municipal, Madrid, Spain

Conference Call and Webcast
The management team will host a conference call with slides for investors on Friday Feb. 9, 2018 at 8:30 a.m. EST to discuss the data and answer questions. Conference call, webcast and post-conference call replay details are as follows:

Domestic: +1.800.239.9838
International: +1.325.794.2551 
Conference ID: 8902500
Webcast: http://public.viavid.com/index.php?id=128119

Replay is available two hours after completion of the call through Feb. 23:
Domestic: +1.844.512.2921
International: +1.412.317.6671
Replay ID: 8902500
The call will also be archived on the Company’s website for 30 days at www.catbio.com.

About Catalyst Biosciences
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.catbio.com.

Forward-Looking Statements
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 the potential uses and benefits of CB 2679d and development plans for this product candidate are 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 trials and enrollment may be delayed and may not have satisfactory outcomes, that human trials will not replicate the results from preclinical studies, 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’s products will be higher than anticipated, competition, and other factors described in the “Risk Factors” section of the Company’s most recent Annual Report on Form 10-K filed with the SEC on March 8, 2017 and Quarterly Report on Form 10-Q filed with the SEC on November 2, 2017. Catalyst does not assume any obligation to update any forward-looking statements, except as required by law.

Contacts:       
                                   
Investors:
Fletcher Payne, CFO
Catalyst Biosciences, Inc.
+1.650.871.0761
[email protected]

Media
Josephine Belluardo, Ph.D.
LifeSci Public Relations
+1.646.751.4361
[email protected]