Exhibit 99.1

CATALYST BIOSCIENCES Corporate Overview 7 February 2020

Forward looking statements Nasdaq: CBIO This presentation includes forward-looking statements Various important factors could cause actual results or that involve substantial risks and uncertainties All events to differ materially, including, but not limited to, the statements included in this presentation, other than risk that additional human trials will not replicate the statement of historical facts, are forward-looking results from earlier trials or animal studies, that potential statements Examples of such statements include, but adverse effects may arise from the testing or use of are not limited to, potential markets for MarzAA, DalcA MarzAA or DalcA, including the generation of antibodies, and CB 2782-PEG, potential benefits of subcutaneous which has been observed in patients treated with DalcA, dosing, potential use of MarzAA as a subcutaneous that clinical trials will take longer than anticipated to be therapy for patients with hemophilia A or B with inhibitors completed, that costs required to develop or manufacture and other bleeding disorders, potential use of DalcA as a the Company’s products will be higher than anticipated, subcutaneous therapy for patients with hemophilia B, that Biogen will discontinue development of CB 2782-potential benefits of CB 2679d-GT as gene therapy, PEG, competition and other factors that affect our ability clinical trial results, plans for a registrational trial for to establish collaborations on commercially reasonable MarzAA in second half of 2020, plans for final Phase 2b terms and other risks described in the “Risk Factors” clinical trial data for DalcA in the second quarter of 2020, section of the Company’s quarterly report on Form 10-Q plans for non-human primate data for CB 2679d-GT in the filed with the Securities and Exchange second quarter of 2020, and potential milestone and Commission on November 7, 2019, and in other filings royalty payments from Biogen Actual results or events with the Securities and Exchange Commission The could differ materially from the plans, expectations and Company does not assume any obligation to update any projections disclosed in these forward-looking statements forward-looking statements, except as required by law catalystbiosciences com 2

Nasdaq: CBIO Essential Medicines – Superior Outcomes Late-Stage Asset Hemophilia Complement SQ Marzeptacog alfa SQ MarzAA IVT Anti-C3 (activated) CB 2782-PEG MarzAA (FVIIa) SQ Dalcinonacog alfa – DalcA (FIX) Phase 3 Ready Factor IX Gene Therapy SQ Systemic Complement Factor Xa Inhibitors Protease Engineering Platform catalystbiosciences com 3

Pipeline Nasdaq: CBIO Hemostasis R PC P1/2 P2 P3 SQ Marzeptacog alfa (activated) “MarzAA” Hemophilia & bleeding disorders (rFVIIa) SQ Dalcinonacog alfa “DalcA” Hemophilia B (rFIX) FIX-Gene Therapy Hemophilia B (CB 2679d-GT) Complement IVT CB 2782-PEG anti-C3 protease for Dry AMD SQ Systemic complement inhibitors catalystbiosciences com 4

Investment highlights Nasdaq: CBIO Novel subcutaneous factors with orphan drug designation, Multi-billion-dollar market FVIIa opportunities MarzAA & DalcA – SQ P2b FIX clinical efficacy demonstrated Anti-C3 collaboration with Biogen Experienced team SQ systemic complement inhibitors research program ~134 worldwide patents – Well funded CBIO retains full ownership $85 M cash (Q3 2019) of all compounds catalystbiosciences com 5

Addressing unmet needs in orphan bleeding disorders Nasdaq: CBIO SQ treatment of bleeds and prophylaxis – $3 7B market Hemophilia A MarzAA & DalcA w/ Inhibitors Hemophilia B Hemophilia B Hemophilia A w/ Inhibitors Factor VII Acquired Deficiency Hemophilia Glanzmann Thrombasthenia catalystbiosciences com 6

The Catalyst Biosciences subcutaneous solution Nasdaq: CBIO Our highly potent candidates + Quick & simple self-administered SQ injection + SQ dosing is the future in hemophilia and other rare hematology indications + Ideal for pediatric patients + Significantly increases half-life + Much higher & more stable factor levels for prophylaxis + Enable SQ treatment of bleeding catalystbiosciences com 7

The new standard in hemophilia prophylaxis Nasdaq: CBIO Patients in high mild range are protected from spontaneous bleeds Normal clotting levels IV treatment SQ treatment 50% Mild Hemophilia Protection from spontaneous hemarthrosis when activity >12% 5% Moderate Hemophilia 15-20 bleeds/year 1% Severe Hemophilia ~30 bleeds/year + Our concept of prophylactic treatment is to keep severe & moderate hemophilia patients in the high mild range + Subcutaneous factor treatments build up over time, offering long-term stability in clotting levels catalystbiosciences com 8

MarzAA is only bypass agent for both SQ prophylaxis and Nasdaq: CBIO SQ treatment of bleeds Attractive commercial profile targeting an existing $2 2B bypass agent market IV NovoSeven ($1 2B 2018 sales) validates SQ MarzAA has a superior profile to IV rFVIIa in multiple rare bleeding disorders NovoSeven – over 100 clinicians surveyed: + Hemophilia A or B with inhibitors + All physicians surveyed indicated a + Severe Factor VII Deficiency preference for SQ MarzAA over IV N7 in + Glanzmann Thrombasthenia one or more settings + Acquired Hemophilia A + SQ MarzAA can create & expand multiple prophylaxis markets catalystbiosciences com 9

Marzeptacog alfa (activated): MarzAA rFVIIa Nasdaq: CBIO SQ prophylaxis and SQ treatment of a bleed are clear unmet needs in hemophilia and other bleeding disorders + Four engineered amino acid substitutions P129A T128N within the FVIIa protein + 9-fold more potent catalytic activity than NovoSeven RT M298Q + Allows subcutaneous dosing + Half-life prolonged when using Q286R subcutaneous dosing Orphan Drug Designation Increased procoagulant activity Granted in the US and EU catalystbiosciences com 10

MarzAA Phase 2 demonstrates clinical efficacy Nasdaq: CBIO Greater than 90% reduction in all bleeding; Median ABR zero; Median bleeding days zero 19 8 12 3% Annualized Proportion of Days Bleed Rate with Bleeding n = 9 n = 9 1 6, p = 0 009 0 8%, p = 0 009 6 m pre-treatment On treatment 6 m pre-treatment On treatment Mean Annualized Bleeding Rates (ABR) significantly reduced from 19 8 to 1 6 Mean Proportion of Days with Bleeding (PDB) significantly reduced from 12 3% to 0 8% Safe & well tolerated, ~1% ISRs (6/517 SQ doses) and no ADAs catalystbiosciences com 11

In a world of SQ prophylaxis: Nasdaq: CBIO Patients need a SQ treatment of a bleed option Individuals on Hemlibra® SQ MarzAA meets the profile for an need additional treatments Ideal Solution  Fast & easy to administer NovoSeven® is safe but is administered IV Stops bleeding in a validated preclinical model Can be safely combined with FEIBA lacks a safety margin Hemlibra and is administered IV Blouse et al ASH 2019 catalystbiosciences com 12

MAA-102 PK dose levels supports treatment of a bleed Nasdaq: CBIO + Dose-proportional increases in Cmax and AUC + 25% of Cmax at 1 hour + 40% of Cmax at 1 5 hours + 50% of Cmax at 2 hours + No ADA Confidential 13

Marzeptacog alfa (activated) Nasdaq: CBIO Phase 3 studies to initiate in 2020 Large commercial opportunity across multiple rare bleeding disorders Demonstrated P2 Clinical efficacy & tolerability for prophylaxis indications Demonstrated preclinical PoC for SQ treatment of a bleed MarzAA can be safely combined with Hemlibra No SQ dose escalation PK/PD study supports treatment of a bleed – final data in Q2 2020 P3 guidance from EMA & MHRA received catalystbiosciences com 14

Dalcinonacog alfa: a novel SQ FIX product Nasdaq: CBIO Three substitutions within the FIX protein: + Increased catalytic activity + Higher affinity for FVIIIa + Resistance to antithrombin inhibition + 22-fold increased potency over BeneFIX Differentiated from marketed IV FIXs: + Simple SQ administration + Potential to maintain continuous protective levels + Small volume injection Resistance to + Enhanced pharmacokinetics with prolonged half-life antithrombin T343R R338E Increased FVIIIa affinity Orphan Drug Designation in US & EU & procoagulant activity catalystbiosciences com 15

Dalcinonacog alfa phase 2b SQ clinical trial design Nasdaq: CBIO Enrollment complete + Primary endpoint: Steady state FIX + 10 severe HB patients screened; 6 dosed activity level above 12% with daily dosing + Rare propeptide mutation excluded + Secondary endpoints: safety including weekly ADA testing, pharmacokinetics, pharmacodynamics, bleeding events, catalystbiosciences com 16

Target levels achieved with 100 IU/kg dosing for 28 Days Nasdaq: CBIO Target FIX >12% Achieved + Dosed 6 severe HB 110 continues 102 withdrew on Day 7 + Steady state FIX levels up to 27% achieved after 14 days + Consistent PK profiles + Terminal half-life is 70-112 hr + No breakthrough bleeds + No ADAs *Data cutoff 05 Feb 2020 catalystbiosciences com 17

Conclusions Nasdaq: CBIO + SQ dalcinonacog alfa provides stable therapeutic levels of Factor IX + Demonstrates the potential to be an effective prophylaxis treatment for individuals with Haemophilia B Trial enrollment complete Excellent & consistent therapeutic FIX activity levels attained Prolonged half-life with SQ administration No SAEs, systemic hypersensitivity, ADAs or nAb to DalcA or wild-type FIX Mild to moderate ISR’s primarily with initial injections No bleeding events during treatment demonstrates effective prophylaxis catalystbiosciences com 18

FIX gene therapy: CB 2679d-GT for hemophilia B Nasdaq: CBIO CB 2679d-GT in combination with a novel chimeric The 8x1010 vg/kg in hemophilia B mice AAV capsid provides significant improvements + Stable high activity levels in a mouse hemophilia B model – FIX AAV Study Dose FIX Activity Transgene Capsid (vg/kg) (U/mL) no nAbs Novel 10 CB 2679d-GT 8 0x10 20 + Vector dose reduced 10-fold compared to current constructs Chimeric + Potential for an improved efficacy & safety profile * 11 Padua TAK-748 7 4x10 20 + AAV license and sponsored research agreement with Padua TAK-748* 7 4x1010 1 Stanford University School of Medicine * Weiller et al (2019) Blood Vol 134, Supplement S1 P4633 Superior preclinical efficacy of CB 2679d-GT vs Padua + 4-5-fold reduction in bleeding time + Activity levels elevated throughout the study—no nAbs Wholly-owned & issued patents covering gene therapy catalystbiosciences com 19 Blouse et al EAHAD 2020

Targeting C3 blocks the downstream complement cascade Nasdaq: CBIO Lectin Pathway Classical Pathway Alternative Pathway C3 Convertase IVT CB 2782-PEG C3 Amplification Loop Antigen uptake Lysis C3a C3b Cell removal Cell death Secretion Inflammation C5 Convertase Proliferation C5a C5 C5b MAC Complex catalystbiosciences com 20

CB 2782-PEG anti-complement factor 3 (C3) protease Nasdaq: CBIO Geographic Atrophy in Dry AMD + Geographic atrophy is an advanced stage of dry age-related macular degeneration that results in the irreversible loss of retina and leads to blindness + Dry AMD affects a million people in the United States and over five million people worldwide + Global market is estimated at >$5B with no approved drugs + C3 is the only clinically validated target for the treatment of Dry AMD Sources: National Eye Institute Facts About Age-Related Macular Degeneration, Tufail 2015, The Eye Diseases Prevalence Research Group 2004, GlobalData catalystbiosciences com 21

CB 2782-PEG long acting anti-C3 protease Nasdaq: CBIO Best-in-class anti-C3 profile for dry AMD Biogen Collaboration + Generated from Catalyst’s proprietary + Announced December 19, 2019 protease engineering platform + $15M upfront, up to $ 340M in milestones + Potent, selective and long acting anti-C3 and tiered royalties up to low double digits protease that degrades C3 into inactive + Catalyst to perform fully funded pre-clinical fragments and manufacturing activities + Preclinical PK & PD data predict + Biogen responsible for IND-enabling best-in-class human intravitreal dosing activities, worldwide clinical development & three or four times a year commercialization + Dry AMD is a $5B+ market opportunity with no approved drugs catalystbiosciences com 22

Milestones Nasdaq: CBIO 2019 Q1 Q2 H2 MarzAA P2 efficacy EoP2 ToB enabling Registration (FVIIa) PK/PD Trial DalcA Positive P2b Update Final P2b data Interim data (FIX) CB 2679d-GT Preclinical efficacy NextGen Vector NHP Efficacy (FIX Gene Therapy) CB 2782-PEG Partnership (dAMD) catalystbiosciences com 23

Financial information Nasdaq: CBIO Selected data Financial results Q3 2019 Cash & Cash Equivalents    $85 0 M Operating Expense (YTD)    $43 3 M Net Loss (YTD)                ($41 6M) Net Loss per share (YTD)    ($3 47) Share data Common Stock Outstanding 12,029,992 Officer & Director ownership    7 0% Fully Diluted Shares*    14,859,051 * Includes ~1M options available for issuance catalystbiosciences com 24

Team Nasdaq: CBIO President & CEO SVP, Technical Operations Nassim Usman, Ph D Andrew Hetherington, M B A 26 years 20 years in biotech in biotech Chief Medical Officer VP, Translational Research Howard Levy, M B B Ch , Ph D , M M M Grant Blouse, Ph D 12 years 18 years in biotech in hematology VP, Business Development Jeffrey Landau, M B A 16 years in biotech catalystbiosciences 25

Summary Nasdaq: CBIO Disruptive approach to billion-dollar markets – protease engineering platform FVIIa: SQ MarzAA ~$2 2B market Anti-C3 dAMD: IVT CB 2782-PEG >$5B market + P2 efficacy & safety demonstrated + Biogen collaboration + P1/2 PK/PD supports ToB + $15M upfront, up to $340M in milestones and tiered royalties up to low double digits + FDA EoP2 in early 2020, P3 expected in 2020 FIX: SQ DalcA >$1 5B market SQ systemic complement inhibitor program + Phase 2b efficacy & safety demonstrated + Large orphan disease opportunity + Builds complement franchise + Final Phase 2b data in 2Q 2020 FIX Gene Therapy: CB 2679d-GT Strong financial position + Proprietary preclinical gene therapy asset with superior activity vs current clinical constructs catalystbiosciences com 26

THANK YOU Nasdaq: CBIO catalystbiosciences com