EX-99.1 2 d86585dex991.htm EX-99.1

Exhibit 99.1 Nasdaq: CBIO CATALYST BIOSCIENCES Corporate Overview 17 November 2020 CatalystBiosciences.com © Catalyst BiosciencesExhibit 99.1 Nasdaq: CBIO CATALYST BIOSCIENCES Corporate Overview 17 November 2020 CatalystBiosciences.com © Catalyst Biosciences

Forward looking statements This presentation includes forward-looking statements that involve Various important factors could cause actual results or events to differ substantial risks and uncertainties All statements included in this materially, including, but not limited to, the risk that trials and studies presentation, other than statement of historical facts, are forward- may be delayed as a result of the novel coronavirus (COVID-19) looking statements. Forward-looking statements include statements outbreak and other factors, that trials may not have satisfactory about the potential benefits of products based on Catalyst’s outcomes, that additional human trials will not replicate the results engineered protease platform; potential markets for and advantages of from earlier trials, that potential adverse effects may arise from the MarzAA and DalcA; plans in Q4 2020 to enroll a pivotal Phase 3 testing or use of DalcA or MarzAA, including the generation of registration study of MarzAA , initiate a Phase 1/2 trial in FVII neutralizing antibodies, which has been observed in patients treated Deficiency, Glanzmann Thrombasthenia, and patients treated with with DalcA, the risk that costs required to develop or manufacture the Hemlibra; the potential for MarzAA and DalcA to effectively and Company’s products will be higher than anticipated, including as a therapeutically treat hemophilia subcutaneously; potential markets for result of delays in development and manufacturing resulting from our anticomplement and gene therapy programs; potential payments COVID-19 and other factors, the risk that Biogen will terminate from Biogen; plans to declare a development candidates in our Catalyst’s agreement, competition and other risks described in the systemic complement program in Q4 2020; the superiority of CB “Risk Factors” section of the Company’s quarterly report filed with the 2679d-GT over other gene therapy candidates; and the Company’s Securities and Exchange Commission on November 5, 2020, and in collaboration with Biogen for the development and commercialization other filings with the Securities and Exchange Commission. The of pegylated CB 2782 for the potential treatment of geographic Company does not assume any obligation to update any forward- atrophy-associated dry age-related macular degeneration (AMD). looking statements, except as required by law. Actual results or events could differ materially from the plans, intentions, expectations and projections disclosed in the forward- looking statements. © Catalyst Biosciences 2Forward looking statements This presentation includes forward-looking statements that involve Various important factors could cause actual results or events to differ substantial risks and uncertainties All statements included in this materially, including, but not limited to, the risk that trials and studies presentation, other than statement of historical facts, are forward- may be delayed as a result of the novel coronavirus (COVID-19) looking statements. Forward-looking statements include statements outbreak and other factors, that trials may not have satisfactory about the potential benefits of products based on Catalyst’s outcomes, that additional human trials will not replicate the results engineered protease platform; potential markets for and advantages of from earlier trials, that potential adverse effects may arise from the MarzAA and DalcA; plans in Q4 2020 to enroll a pivotal Phase 3 testing or use of DalcA or MarzAA, including the generation of registration study of MarzAA , initiate a Phase 1/2 trial in FVII neutralizing antibodies, which has been observed in patients treated Deficiency, Glanzmann Thrombasthenia, and patients treated with with DalcA, the risk that costs required to develop or manufacture the Hemlibra; the potential for MarzAA and DalcA to effectively and Company’s products will be higher than anticipated, including as a therapeutically treat hemophilia subcutaneously; potential markets for result of delays in development and manufacturing resulting from our anticomplement and gene therapy programs; potential payments COVID-19 and other factors, the risk that Biogen will terminate from Biogen; plans to declare a development candidates in our Catalyst’s agreement, competition and other risks described in the systemic complement program in Q4 2020; the superiority of CB “Risk Factors” section of the Company’s quarterly report filed with the 2679d-GT over other gene therapy candidates; and the Company’s Securities and Exchange Commission on November 5, 2020, and in collaboration with Biogen for the development and commercialization other filings with the Securities and Exchange Commission. The of pegylated CB 2782 for the potential treatment of geographic Company does not assume any obligation to update any forward- atrophy-associated dry age-related macular degeneration (AMD). looking statements, except as required by law. Actual results or events could differ materially from the plans, intentions, expectations and projections disclosed in the forward- looking statements. © Catalyst Biosciences 2

Catalyst Biosciences – Protease medicines Protease engineering platform Late-stage asset Hemophilia Complement SQ MarzAA (FVIIa) IVT Anti-C3 Dry AMD SQ Marzeptacog alfa CB 2782-PEG (activated) SQ Dalcinonacog MarzAA (FVIIa) alfa – DalcA (FIX) Factor IX Gene Therapy SQ Systemic Phase 3 in 2020 Complement Factor Xa Inhibitors © Catalyst Biosciences 3Catalyst Biosciences – Protease medicines Protease engineering platform Late-stage asset Hemophilia Complement SQ MarzAA (FVIIa) IVT Anti-C3 Dry AMD SQ Marzeptacog alfa CB 2782-PEG (activated) SQ Dalcinonacog MarzAA (FVIIa) alfa – DalcA (FIX) Factor IX Gene Therapy SQ Systemic Phase 3 in 2020 Complement Factor Xa Inhibitors © Catalyst Biosciences 3

Harnessing the catalytic power of proteases One protease molecule regulates 1000s of target molecules Therapeutic protease Target protein An adaptable protease platform Demonstrated efficacy of clinical stage assets Functionally enhanced natural proteases (FVIIa, FIX) Specific cleavage site Engineered novel protein degraders (Anti-C3) Ideal for high concentration drug targets or controlling amplification cascades Potential to address novel targets Increased potency and extended half-life variants © Catalyst Biosciences 4Harnessing the catalytic power of proteases One protease molecule regulates 1000s of target molecules Therapeutic protease Target protein An adaptable protease platform Demonstrated efficacy of clinical stage assets Functionally enhanced natural proteases (FVIIa, FIX) Specific cleavage site Engineered novel protein degraders (Anti-C3) Ideal for high concentration drug targets or controlling amplification cascades Potential to address novel targets Increased potency and extended half-life variants © Catalyst Biosciences 4

Pipeline R PC P1/2 P2 P3 Hemostasis SQ Marzeptacog alfa (activated) MarzAA” Hem A or B with inhibitors – ToB FVIID/Glanzmann/Hemlibra – ToB SQ Dalcinonacog alfa “DalcA” Hem B (rFIX) FIX-Gene Therapy Hem B (CB 2679d-GT) Complement IVT CB 2782-PEG Anti-C3 protease for Dry AMD SQ systemic complement inhibitors – CB DC © Catalyst Biosciences 5Pipeline R PC P1/2 P2 P3 Hemostasis SQ Marzeptacog alfa (activated) MarzAA” Hem A or B with inhibitors – ToB FVIID/Glanzmann/Hemlibra – ToB SQ Dalcinonacog alfa “DalcA” Hem B (rFIX) FIX-Gene Therapy Hem B (CB 2679d-GT) Complement IVT CB 2782-PEG Anti-C3 protease for Dry AMD SQ systemic complement inhibitors – CB DC © Catalyst Biosciences 5

Investment highlights Novel subcutaneous factors Anti-C3 Dry AMD with Biogen with orphan drug designation; FVIIa SQ systemic complement MarzAA & DalcA – P2 efficacy FIX regulator research program in prophylaxis studies complete Multibillion-dollar market Experienced team opportunities 178 worldwide patents Strong balance sheet, CBIO retains full ownership $104M cash – Q3 of all compounds © Catalyst Biosciences 6 6Investment highlights Novel subcutaneous factors Anti-C3 Dry AMD with Biogen with orphan drug designation; FVIIa SQ systemic complement MarzAA & DalcA – P2 efficacy FIX regulator research program in prophylaxis studies complete Multibillion-dollar market Experienced team opportunities 178 worldwide patents Strong balance sheet, CBIO retains full ownership $104M cash – Q3 of all compounds © Catalyst Biosciences 6 6

Marzeptacog alfa (activated): MarzAA rFVIIa Addresses a clear unmet need in hemophilia & other bleeding disorders P129A T128N 9-fold higher activity vs NovoSeven RT + Potency allows for SQ dosing that prolongs half-life + Simple, small volume SQ administration M298Q Preclinical efficacy of SQ on-demand treatment Q286R + HA mouse after tail cut; HA dog; HA rat P2/3 prophylaxis efficacy & safety in HA or HB with inhibitors Increased procoagulant + 46 patients treated including: single dose IV, up to 3 SQ activity doses/day, & daily SQ up to 97 days © Catalyst Biosciences 7Marzeptacog alfa (activated): MarzAA rFVIIa Addresses a clear unmet need in hemophilia & other bleeding disorders P129A T128N 9-fold higher activity vs NovoSeven RT + Potency allows for SQ dosing that prolongs half-life + Simple, small volume SQ administration M298Q Preclinical efficacy of SQ on-demand treatment Q286R + HA mouse after tail cut; HA dog; HA rat P2/3 prophylaxis efficacy & safety in HA or HB with inhibitors Increased procoagulant + 46 patients treated including: single dose IV, up to 3 SQ activity doses/day, & daily SQ up to 97 days © Catalyst Biosciences 7

SQ MarzAA is a large commercial opportunity Global NovoSeven sales breakdown SQ MarzAA has a superior profile by indication (2019) Faster & easier to administer vs N7 dosed every 2 hours IV until hemostasis $139M MarzAA SQ half-life ~8x longer than N7 $63M 9-fold higher activity vs N7 $93M $578M Potential to reduce rebleeding $1.2B $81M Stops bleeding in multiple preclinical models Can be combined with Hemlibra in vitro without increased thrombogenicity $263M Ideal for pediatrics and patients with venous access issues Hem A Inh (47%) Hem B Inh (11%) Prophylaxis efficacy demonstrated in P2 Other (22%) FVII Def (5%) Glanzmann (7%) AHA (8%) Source: Adivo Associates market research; Catalyst Biosciences market research. Data on file © Catalyst Biosciences 8SQ MarzAA is a large commercial opportunity Global NovoSeven sales breakdown SQ MarzAA has a superior profile by indication (2019) Faster & easier to administer vs N7 dosed every 2 hours IV until hemostasis $139M MarzAA SQ half-life ~8x longer than N7 $63M 9-fold higher activity vs N7 $93M $578M Potential to reduce rebleeding $1.2B $81M Stops bleeding in multiple preclinical models Can be combined with Hemlibra in vitro without increased thrombogenicity $263M Ideal for pediatrics and patients with venous access issues Hem A Inh (47%) Hem B Inh (11%) Prophylaxis efficacy demonstrated in P2 Other (22%) FVII Def (5%) Glanzmann (7%) AHA (8%) Source: Adivo Associates market research; Catalyst Biosciences market research. Data on file © Catalyst Biosciences 8

MarzAA could be the first prophylaxis for Glanzmann & FVIID Growing number of Glanzmann and FVIID patients treated with NovoSeven $144M $131M $121M 9% total increase in patients over 3 years 2017 2018 2019 Unmet need in Global NovoSeven on demand sales prophylaxis Glanzmann, FVIID Source: Catalyst Biosciences, Adivo Associates Market Research, Data on file. *Note: Treated patients may be counted multiple times as patients may have multiple bleeding events per year needing factor treatment © Catalyst Biosciences 9MarzAA could be the first prophylaxis for Glanzmann & FVIID Growing number of Glanzmann and FVIID patients treated with NovoSeven $144M $131M $121M 9% total increase in patients over 3 years 2017 2018 2019 Unmet need in Global NovoSeven on demand sales prophylaxis Glanzmann, FVIID Source: Catalyst Biosciences, Adivo Associates Market Research, Data on file. *Note: Treated patients may be counted multiple times as patients may have multiple bleeding events per year needing factor treatment © Catalyst Biosciences 9

MarzAA is efficacious with daily prophylaxis Phase 2: Daily SQ dosing for 44 – 97 days Annualized bleed rate Proportion of days n = 9 with bleeding n = 9 12.3% 19.8 + Greater than 90% reduction in all bleeding – Median ABR = 0 + 2 subjects had dose escalation from 30 to 60 μg/kg + Safe & well tolerated, ~1% ISR (6/517 doses) & no ADA 0.8%, p = 0.009 1.6, p = 0.009 6 m pre-treatment On treatment 6 m pre-treatment On treatment Mahlangu et al. EAHAD 2020 © Catalyst Biosciences 10MarzAA is efficacious with daily prophylaxis Phase 2: Daily SQ dosing for 44 – 97 days Annualized bleed rate Proportion of days n = 9 with bleeding n = 9 12.3% 19.8 + Greater than 90% reduction in all bleeding – Median ABR = 0 + 2 subjects had dose escalation from 30 to 60 μg/kg + Safe & well tolerated, ~1% ISR (6/517 doses) & no ADA 0.8%, p = 0.009 1.6, p = 0.009 6 m pre-treatment On treatment 6 m pre-treatment On treatment Mahlangu et al. EAHAD 2020 © Catalyst Biosciences 10

Current bypass agents require multiple IVs over the course of hours NovoSeven 6 hours + Patients reported needing an average of 6 hours and 3 injections of NovoSeven 72 to resolve bleeds + Some bleeds take longer Hours 1,2,3 than 72 hours to resolve 1 2 3 Source: NovoSeven PI Rev 7/2020; Adivo Associates market research; Catalyst Biosciences market research. Data on file © Catalyst Biosciences 11Current bypass agents require multiple IVs over the course of hours NovoSeven 6 hours + Patients reported needing an average of 6 hours and 3 injections of NovoSeven 72 to resolve bleeds + Some bleeds take longer Hours 1,2,3 than 72 hours to resolve 1 2 3 Source: NovoSeven PI Rev 7/2020; Adivo Associates market research; Catalyst Biosciences market research. Data on file © Catalyst Biosciences 11

MAA-102: PK MarzAA levels support SQ treatment of a bleed 8 subjects at each dose level 100 60 μg/kg SQ 3-hou 60 μg/kg SQ 3-hourly x3 + Target of 24-120 ng/mL to treat a 60 μg/kg SQ 3-hou 60 μg/kg SQ 3-hourly x2 bleed is based on continuous 60 μg/kg SQ 1x 60 μg/kg SQ 1x 80 infusion levels of NovoSeven for hemostasis during surgery 60 + Target levels are rapidly achieved 40 + Target levels can be maintained for MarzAA M 18 hours with a single SQ dose of target level 20 60 μg/kg + No ADA 0 0 6 12 18 24 30 36 42 48 Hours Neuman et al. ISTH 2020 © Catalyst Biosciences 12 MarzAA (ng/mL) MAA-102: PK MarzAA levels support SQ treatment of a bleed 8 subjects at each dose level 100 60 μg/kg SQ 3-hou 60 μg/kg SQ 3-hourly x3 + Target of 24-120 ng/mL to treat a 60 μg/kg SQ 3-hou 60 μg/kg SQ 3-hourly x2 bleed is based on continuous 60 μg/kg SQ 1x 60 μg/kg SQ 1x 80 infusion levels of NovoSeven for hemostasis during surgery 60 + Target levels are rapidly achieved 40 + Target levels can be maintained for MarzAA M 18 hours with a single SQ dose of target level 20 60 μg/kg + No ADA 0 0 6 12 18 24 30 36 42 48 Hours Neuman et al. ISTH 2020 © Catalyst Biosciences 12 MarzAA (ng/mL)

Crimson 1 Phase 3 study: Treatment of episodic bleeding Hemophilia A or B with inhibitors, ABR ≥ 8 N = 30 N = 30 Primary endpoint ● MarzAA SQ SOC IV Non-inferior hemostatic efficacy: 60 µg/kg 1-3 doses standard 4-point scale at 24 h ≤5 bleeds ≤5 bleeds 1-3 doses per patient per patient Secondary endpoints ● Time to bleed resolution; 130 bleeds number of doses; rescue meds 130 bleeds per sequence per sequence Safety ● Adverse events, anti-drug antibodies (ADA); thrombosis MarzAA SQ Statistics SOC IV 60 µg/kg 1-3 doses ≤5 bleeds + SOC estimate 85% ≤5 bleeds 1-3 doses per patient per patient Excellent/good treatment of bleeds + Non-inferiority margin of 12% 114 bleeds per 114 bleeds + 2.5% significance, one-sided sequence per sequence + 90% power © Catalyst Biosciences 13Crimson 1 Phase 3 study: Treatment of episodic bleeding Hemophilia A or B with inhibitors, ABR ≥ 8 N = 30 N = 30 Primary endpoint ● MarzAA SQ SOC IV Non-inferior hemostatic efficacy: 60 µg/kg 1-3 doses standard 4-point scale at 24 h ≤5 bleeds ≤5 bleeds 1-3 doses per patient per patient Secondary endpoints ● Time to bleed resolution; 130 bleeds number of doses; rescue meds 130 bleeds per sequence per sequence Safety ● Adverse events, anti-drug antibodies (ADA); thrombosis MarzAA SQ Statistics SOC IV 60 µg/kg 1-3 doses ≤5 bleeds + SOC estimate 85% ≤5 bleeds 1-3 doses per patient per patient Excellent/good treatment of bleeds + Non-inferiority margin of 12% 114 bleeds per 114 bleeds + 2.5% significance, one-sided sequence per sequence + 90% power © Catalyst Biosciences 13

MAA-202 Phase 1/2 study design FVII deficiency, Glanzmann thrombasthenia and HA on Hemlibra: N = 8 each Phase 1 PK Phase 2 ToB Phase 1 ● Primary endpoint: MarzAA IV MarzAA SQ Pharmacokinetics each cohort 1-3 doses Secondary endpoint: Pharmacodynamics FVIID ≥30 bleeds Single dose ● Phase 2 ToB MarzAA SQ Primary endpoint: Hemostatic efficacy at 24 hours GT ≥30 bleeds Secondary endpoints: Single dose escalation Effective hemostasis at successive timepoints; doses needed; rescue meds Safety: Multiple dose Q3H HA ≥15 bleeds Adverse events and ADA © Catalyst Biosciences 14MAA-202 Phase 1/2 study design FVII deficiency, Glanzmann thrombasthenia and HA on Hemlibra: N = 8 each Phase 1 PK Phase 2 ToB Phase 1 ● Primary endpoint: MarzAA IV MarzAA SQ Pharmacokinetics each cohort 1-3 doses Secondary endpoint: Pharmacodynamics FVIID ≥30 bleeds Single dose ● Phase 2 ToB MarzAA SQ Primary endpoint: Hemostatic efficacy at 24 hours GT ≥30 bleeds Secondary endpoints: Single dose escalation Effective hemostasis at successive timepoints; doses needed; rescue meds Safety: Multiple dose Q3H HA ≥15 bleeds Adverse events and ADA © Catalyst Biosciences 14

Dalcinonacog alfa: novel FIX replacement for SQ delivery Three amino acid substitutions + 22-fold increased potency vs BeneFIX Differentiated from marketed IV FIXs + Small volume SQ administration R318Y + Enhanced pharmacokinetics with prolonged half-life + Excellent extravascular distribution + Potential to maintain continuous protective levels Resistance to T343R R338E antithrombin Increased FVIIIa affinity & procoagulant activity © Catalyst Biosciences 15Dalcinonacog alfa: novel FIX replacement for SQ delivery Three amino acid substitutions + 22-fold increased potency vs BeneFIX Differentiated from marketed IV FIXs + Small volume SQ administration R318Y + Enhanced pharmacokinetics with prolonged half-life + Excellent extravascular distribution + Potential to maintain continuous protective levels Resistance to T343R R338E antithrombin Increased FVIIIa affinity & procoagulant activity © Catalyst Biosciences 15

DalcA P2b demonstrated efficacy & safety Target levels >12% achieved with daily SQ 100 IU/kg dosing for 28 days + Dosed 6 severe HB subjects § Subject 102 withdrew on Day 7 + Steady state FIX levels up to 27% achieved after 14 days + No breakthrough bleeds Target + No neutralizing ADA Level + Mild to moderate ISR – transient & Wash-Out self-limiting + Terminal half-life is Days 2.5 - 5.1 days © Catalyst Biosciences 16 Factor IX Activity (%)DalcA P2b demonstrated efficacy & safety Target levels >12% achieved with daily SQ 100 IU/kg dosing for 28 days + Dosed 6 severe HB subjects § Subject 102 withdrew on Day 7 + Steady state FIX levels up to 27% achieved after 14 days + No breakthrough bleeds Target + No neutralizing ADA Level + Mild to moderate ISR – transient & Wash-Out self-limiting + Terminal half-life is Days 2.5 - 5.1 days © Catalyst Biosciences 16 Factor IX Activity (%)

Catalyst’s CB 2679d gene therapy for hemophilia B CB 2679d-GT has a superior profile vs Padua in preclinical studies + Stable high activity levels with 1/10th vector dose in mouse model Novel Engineered Lower AAV + 4 to 5-fold reduction in bleeding time when Transgene Capsid Dose compared to the Padua + Potential for improved efficacy & safety at 1-2 log FIX AAV Study Dose FIX Activity reduced dose Transgene Capsid (vg/kg) (U/mL) Novel 10 * CB 2679d-GT 8.0x10 20 Achieved high initial FIX levels Chimeric in NHP * 11 Padua TAK-748 7.4x10 20 + Presented at World Federation of Hemophilia Virtual Summit 2020 * 10 Padua TAK-748 7.4x10 1 + Additional vector optimization & dose ranging *Weiller et al. (2019) Blood Vol. 134, Supplement S1 P4633 studies ongoing Wholly-owned & issued patents License & sponsored research agreement covering gene therapy © Catalyst Biosciences 17Catalyst’s CB 2679d gene therapy for hemophilia B CB 2679d-GT has a superior profile vs Padua in preclinical studies + Stable high activity levels with 1/10th vector dose in mouse model Novel Engineered Lower AAV + 4 to 5-fold reduction in bleeding time when Transgene Capsid Dose compared to the Padua + Potential for improved efficacy & safety at 1-2 log FIX AAV Study Dose FIX Activity reduced dose Transgene Capsid (vg/kg) (U/mL) Novel 10 * CB 2679d-GT 8.0x10 20 Achieved high initial FIX levels Chimeric in NHP * 11 Padua TAK-748 7.4x10 20 + Presented at World Federation of Hemophilia Virtual Summit 2020 * 10 Padua TAK-748 7.4x10 1 + Additional vector optimization & dose ranging *Weiller et al. (2019) Blood Vol. 134, Supplement S1 P4633 studies ongoing Wholly-owned & issued patents License & sponsored research agreement covering gene therapy © Catalyst Biosciences 17

Targeting complement – a pathway regulated by proteases Dysregulated complement activity is associated with a broad range of disorders and a logical fit for our protease platform Antigen Classical C3a antibody pathway complexes Immune response inflammation Lectin Pathogen C3b C3 C5a C5 pathway surfaces CB 2782-PEG Targeting C3 blocks Activating Alternate C5b downstream surfaces and pathway C3 tick-over complement Membrane attack complex (MAC) Autoimmune diseases Inflammatory diseases Multiple rare diseases © Catalyst Biosciences 18Targeting complement – a pathway regulated by proteases Dysregulated complement activity is associated with a broad range of disorders and a logical fit for our protease platform Antigen Classical C3a antibody pathway complexes Immune response inflammation Lectin Pathogen C3b C3 C5a C5 pathway surfaces CB 2782-PEG Targeting C3 blocks Activating Alternate C5b downstream surfaces and pathway C3 tick-over complement Membrane attack complex (MAC) Autoimmune diseases Inflammatory diseases Multiple rare diseases © Catalyst Biosciences 18

CB 2782-PEG long acting anti-C3 protease Best-in-class anti-C3 profile for dry AMD with dosing every 3 to 4 months Non-Human Primates (vitreous) Human Modeling Time (days) Time (days) Predicted >90% elimination of C3 at 4 months © Catalyst Biosciences 19 C3 Concentration (nM) CB 2782-PEG Concentration (nM) C3 Concentration (nM)CB 2782-PEG long acting anti-C3 protease Best-in-class anti-C3 profile for dry AMD with dosing every 3 to 4 months Non-Human Primates (vitreous) Human Modeling Time (days) Time (days) Predicted >90% elimination of C3 at 4 months © Catalyst Biosciences 19 C3 Concentration (nM) CB 2782-PEG Concentration (nM) C3 Concentration (nM)

CB 2782-PEG: Complement factor 3 (C3) cleaving protease Geographic atrophy in dry AMD can result in blindness + Geographic atrophy is an advanced stage of dry age-related macular degeneration (dAMD) + dAMD affects ~1M people in the US and over 5M worldwide + Global market estimated at >$5B + C3 is the only clinically validated target (randomized P2) for the treatment of dAMD + No currently approved therapy Sources: National Eye Institute. Facts About Age-Related Macular Degeneration, Tufail 2015, The Eye Diseases Prevalence Research Group 2004, GlobalData © Catalyst Biosciences 20CB 2782-PEG: Complement factor 3 (C3) cleaving protease Geographic atrophy in dry AMD can result in blindness + Geographic atrophy is an advanced stage of dry age-related macular degeneration (dAMD) + dAMD affects ~1M people in the US and over 5M worldwide + Global market estimated at >$5B + C3 is the only clinically validated target (randomized P2) for the treatment of dAMD + No currently approved therapy Sources: National Eye Institute. Facts About Age-Related Macular Degeneration, Tufail 2015, The Eye Diseases Prevalence Research Group 2004, GlobalData © Catalyst Biosciences 20

CB 2782-PEG long acting anti-C3 protease Best-in-class anti-C3 profile for dry AMD Biogen collaboration + Generated from Catalyst’s proprietary + Announced December 2019 protease engineering platform + $15M upfront, up to $340M in milestones and + Potent, selective and long acting anti-C3 tiered royalties up to low double digits protease that degrades C3 into inactive + Catalyst to perform fully funded pre-clinical and fragments manufacturing activities + Preclinical NHP PK & PD data* predict + Biogen responsible for IND-enabling activities, best-in-class human intravitreal dosing three worldwide clinical development or four times a year & commercialization *Furfine et al. ARVO 2019 © Catalyst Biosciences 21CB 2782-PEG long acting anti-C3 protease Best-in-class anti-C3 profile for dry AMD Biogen collaboration + Generated from Catalyst’s proprietary + Announced December 2019 protease engineering platform + $15M upfront, up to $340M in milestones and + Potent, selective and long acting anti-C3 tiered royalties up to low double digits protease that degrades C3 into inactive + Catalyst to perform fully funded pre-clinical and fragments manufacturing activities + Preclinical NHP PK & PD data* predict + Biogen responsible for IND-enabling activities, best-in-class human intravitreal dosing three worldwide clinical development or four times a year & commercialization *Furfine et al. ARVO 2019 © Catalyst Biosciences 21

CB 4332 SQ long-acting systemic complement regulator Non-human primate PK supports weekly SQ dosing in humans CB 4332 Expanding the complement portfolio + Leverages Catalyst’s proprietary protease engineering platform + Designed for SQ administration with improved bioavailability Parent Functional Molecule + Simple & efficient production process Improvements + Program update in Q4 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Days © Catalyst Biosciences 22 Plasma levelCB 4332 SQ long-acting systemic complement regulator Non-human primate PK supports weekly SQ dosing in humans CB 4332 Expanding the complement portfolio + Leverages Catalyst’s proprietary protease engineering platform + Designed for SQ administration with improved bioavailability Parent Functional Molecule + Simple & efficient production process Improvements + Program update in Q4 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Days © Catalyst Biosciences 22 Plasma level

Milestones – 2020 Q1 2020 Q2 2020 Q3 2020 Q4 2020 EoP2 ToB PK/PD MAA-102 data Enroll pivotal P3 Initiate P1/2 in FVII Interim P2b Final P2b Population PK deficiency, Glanzmann Thrombasthenia, and NextGen vector NHP efficacy Hemlibra patients Development MarzAA DalcA CB 2679d-GT CB 2782-PEG CB DC candidate (FVIIa) (FIX) (FIX gene therapy) (dAMD) (Systemic complement) © Catalyst Biosciences 23Milestones – 2020 Q1 2020 Q2 2020 Q3 2020 Q4 2020 EoP2 ToB PK/PD MAA-102 data Enroll pivotal P3 Initiate P1/2 in FVII Interim P2b Final P2b Population PK deficiency, Glanzmann Thrombasthenia, and NextGen vector NHP efficacy Hemlibra patients Development MarzAA DalcA CB 2679d-GT CB 2782-PEG CB DC candidate (FVIIa) (FIX) (FIX gene therapy) (dAMD) (Systemic complement) © Catalyst Biosciences 23

Team Nassim Usman, Ph.D. Grant Blouse, Ph.D. President & CEO SVP Translational Research 28 years in biotech 13 years in biotech Clinton Musil, M.B.A Jeffrey Landau, M.B.A. Chief Financial Officer SVP Business Development 16 years in biotech & investing/banking 18 years in biotech Howard Levy, M.B.B.Ch., Ph.D. Anju Chatterji, Ph.D. Chief Medical Officer SVP Biologics Development & Manufacturing 19 years in biotech 20 years in hematology © Catalyst Biosciences 24Team Nassim Usman, Ph.D. Grant Blouse, Ph.D. President & CEO SVP Translational Research 28 years in biotech 13 years in biotech Clinton Musil, M.B.A Jeffrey Landau, M.B.A. Chief Financial Officer SVP Business Development 16 years in biotech & investing/banking 18 years in biotech Howard Levy, M.B.B.Ch., Ph.D. Anju Chatterji, Ph.D. Chief Medical Officer SVP Biologics Development & Manufacturing 19 years in biotech 20 years in hematology © Catalyst Biosciences 24

Summary Disruptive approach to billion-dollar markets – protease engineering platform FVIIa: SQ MarzAA ~$2.2B market Anti-C3 dAMD: IVT CB 2782-PEG >$5B market + P1 PK/PD & preclinical data supports ToB + Biogen collaboration + P2 efficacy & safety demonstrated + $15M upfront, up to $340M in milestones, up to low double digits tiered royalties + P3 patient enrollment in Q4 2020 SQ systemic complement inhibitor program FIX: SQ DalcA >$1.8B market + Large $B+ rare disease opportunity + Phase 2b efficacy & safety demonstrated + Multiple indications & applications + Potential for less frequent dosing st + 1 development candidate in Q4 2020 FIX Gene Therapy: CB 2679d-GT Well capitalized + Proprietary preclinical gene therapy asset with superior activity and lower dose vs + Cash runway into 2022 current clinical constructs © Catalyst Biosciences 25Summary Disruptive approach to billion-dollar markets – protease engineering platform FVIIa: SQ MarzAA ~$2.2B market Anti-C3 dAMD: IVT CB 2782-PEG >$5B market + P1 PK/PD & preclinical data supports ToB + Biogen collaboration + P2 efficacy & safety demonstrated + $15M upfront, up to $340M in milestones, up to low double digits tiered royalties + P3 patient enrollment in Q4 2020 SQ systemic complement inhibitor program FIX: SQ DalcA >$1.8B market + Large $B+ rare disease opportunity + Phase 2b efficacy & safety demonstrated + Multiple indications & applications + Potential for less frequent dosing st + 1 development candidate in Q4 2020 FIX Gene Therapy: CB 2679d-GT Well capitalized + Proprietary preclinical gene therapy asset with superior activity and lower dose vs + Cash runway into 2022 current clinical constructs © Catalyst Biosciences 25

THANK YOU Nasdaq: CBIO CatalystBiosciences.com © Catalyst BiosciencesTHANK YOU Nasdaq: CBIO CatalystBiosciences.com © Catalyst Biosciences