Sutro Biopharma, Inc. · NASDAQ:STRO
Sutro Biopharma — Investor Presentation (September 2025)
29 slides from Sutro Biopharma's investor presentation, September 2025
Slide 1: Designed to Deliver – September 2025
DESIGNED / |O DELIVER September 2025
Slide 2: Forward-Looking Statements
Forward-Looking Statements This presentation and the accompanying oral presentation contain “forward-looking” statements that are based on our management’s beliefs and assumptions and on information currently available to management. Forward-looking statements include all statements other than state
Slide 3: Proprietary Platform Creates Best-in-Class ADCs
Proprietary Platform Creates Best-in-Class ADCs At the forefront of next-gen ADCs, with improved antibody, linker, and payload for superior safety and efficacy Single-payload ADCs Dual-payload ADCs, with partnered and for complex targets where wholly-owned programs, to overcome competition is limite
Slide 4: Differentiated Pipeline of Single- and Dual-Payload ADCs
Differentiated Pipeline of Single- and Dual-Payload ADCs SINGLE-PAYLOAD ADCs: DUAL-PAYLOAD ADCs: Focused on Complex Targets Overcome Resistance and Expressed Across Many Tumor Types Delay Progression STRO-00X and STRO-00Y: STRO-004: STRO-006: Dual-Payload ADCs TF-Targeting ADC ITGB6-Targeting ADC S
Slide 5: Next-Generation ADCs
Next-Generation ADCs Enabled by Sutro’s Proprietary Platform
Slide 6: Designed to Deliver: Precision, Versatility, Scalability
Designed to Deliver: Proprietary platform enables enhanced ADCs Precision Versatility Scalability Site-specific conjugation Increased flexibility on linker- Same cell-free system from using non-natural amino acids payload number, placement, discovery to commercial and click chemistry or combinations
Slide 7: Sutro's Platform Designed to Optimize Every Component of the ADC
Sutro’s Platform Designed to Optimize Every Component of the ADC Expanding the therapeutic window to minimize toxicity and maximize efficacy 1 1 ANTIBODY ▸High throughput screening identifies Ab with ideal attributes ▸Reduced ILD risk enabled by Fc-silent design 2 PAYLOAD ▸High DAR exatecans; stable
Slide 8: Our Proprietary Platform Enables Industry-Leading ADC Exposure
Our Proprietary Platform Enables Industry-Leading ADC Exposure, a Key Driver of Safety and Efficacy Comparing ADC exposure in NHPs at highest non-severely toxic dose 6,000 Conjugated PL Exposure [h ug/mL] 5,000 STRO-ADC DAR8 4,000 STRO-ADC STRO-ADC DAR8 DAR8 j 3,000 Exatecan/Topo1i ADCs Enhertu DAR8
Slide 9: STRO-004
STRO-004 Potential Best-in-Class Exatecan ADC Targeting Tissue Factor
Slide 10: STRO-004: Potent TF-Targeting Exatecan ADC Engineered for Robust Exposure and Efficacy
STRO-004: Potent TF-Targeting Exatecan ADC Engineered for Robust Exposure and Efficacy 50x preclinical exposure vs approved TF ADC 1 1 ANTIBODY ▸Tumor targeting, does not interfere with TF biology ▸Fc-silent to reduce ILD risk 2 PAYLOAD ▸DAR 8; safely boosts potency ▸Drives efficacy in low-copy targ
Slide 11: Significant Unmet Need Across Large Oncology Patient Populations
Significant Unmet Need Across Large Oncology Patient Populations STRO-004 demonstrated activity supporting broad indication potential, beyond cervical cancer Incidence (U.S.) Across Select Relevant Tumor Types Phase 1 Basket Trial: Dose Escalation/Expansion Designed to quickly identify a go-forward
Slide 12: STRO-004: Favorable In Vitro Tolerability Profile vs. Approved TF ADC
STRO-004: Favorable In Vitro Tolerability Profile vs. Approved TF ADC Eye Inflammation Skin Toxicities Human Corneal Epithelial Cells Human Keratinocyte STRO-004 (DAR8-exatecan) Approved TF ADC (DAR4-MMAE) DAR – Drug to a ntib ody ra tio; MMA E – Monomethyl aurista tin E; TF – Tissue factor NON-CONF
Slide 13: STRO-004: Promising Anti-Tumor Activity in Multiple TF-Expressing Cancer Models
STRO-004: Promising Anti-Tumor Activity in Multiple TF-Expressing Cancer Models > 50% of tumors respond to STRO-004 at low dose STRO-004, 5 mg/kg single dose Approved TF ADC (DAR4 MMAE), ~3 mg/kg single dose DAR – Drug to a ntib ody ra tio; NS CLC – Non-small cell lung cancer; MMAE – Monomethyl auri
Slide 14: STRO-006
STRO-006 Potential Best-in-Class Exatecan ADC Targeting Integrin-Beta 6
Slide 15: STRO-006: Selective ITGB6-Targeting Exatecan ADC for Leading Tolerability and PK
STRO-006: Selective ITGB6-Targeting Exatecan ADC for Leading Tolerability and PK 2-3x higher drug exposure than many conventional ADCs 1 1 ANTIBODY ▸High affinity to ITGB6 without effect on TGFβ signaling ▸Fc-silent to reduce ILD risk 2 PAYLOAD ▸ High stable DAR (8) ▸ Potent anti-tumor activity with
Slide 16: ITGB6: Attractive Broad Solid Tumor Target but Biologically Complex
ITGB6: Attractive Broad Solid Tumor Target but Biologically Complex—Requires Advanced Engineering Leukocyte-specific receptors Collagen receptors αL αM αX αD α1 α2 β2 α9 α10 αE β7 α4 α11 β1 α5 α7 αIIb β3 αv α8 α6 β5 α3 β4 β6 β8 RCD receptors Laminin receptors ITGB6 is part of the αvβ6 heterodimer, w
Slide 17: STRO-006 is Designed for Superior Selectivity, Safety and Stability
STRO-006 is Designed for Superior Selectivity, Safety and Stability STRO-006 Binds Specifically to αvβ6 STRO-006 Exhibits Favorable Safety, PK, and Not Other Integrin Family Members and Stability Profile in NHP Studies • No measurable effect on TGFβ signaling in vitro • Well-tolerated up to 25 mg/kg
Slide 18: ITGB6 Expression has Unique Promise in NSCLC as well as Other Common Solid Tumors
ITGB6 Expression has Unique Promise in NSCLC as well as Other Common Solid Tumors STRO-006 is designed for monotherapy and combination use, expanding its therapeutic reach Incidence (U.S.) Across Select Relevant Tumor Types 40,000 75,000 150,000 200,000 TNBC HNSCC CRC Lung ITGβ6 expression assumptio
Slide 19: Single Dose of STRO-006 Drove Durable Tumor Response in Xenograft Models
Single Dose of STRO-006 Drove Durable Tumor Response in Xenograft Models at ≤10 mg/kg Head and Neck (ITGB6+) Bladder (ITGB6++) Lung (ITGB6+++) ITG B6 – Integrin beta 6; MMAE – Monomethyl aurista tin E NON-CONFIDENTIAL 19
Slide 20: Delivering Dual-Payloads: The Next Revolution in ADCs
Delivering Dual-Payloads: The Next Revolution in ADCs
Slide 21: Dual-Payload ADCs: Targeted Combination Therapy to Improve Outcomes
Dual-Payload ADCs: Targeted Combination Therapy to Improve Outcomes Combination treatment approaches have been shown to improve outcomes in oncology vs single agent chemotherapy and remain standard of care in many therapeutic areas Dual-Payload ADCs: Potential to Become Future Standard of Care • Ove
Slide 22: Proprietary Cell-Free Platform Positions Sutro at the Forefront of Dual-Payload Innovation
Proprietary Cell-Free Platform Positions Sutro at the Forefront of Dual-Payload Innovation Enables novel drug combinations and ratios with the broadest payload diversity to overcome tumor resistance and improve tolerability Topo1 x Tubulin Improved clinical activity when combining Topo1 and Tubulin
Slide 23: Potential for Greater Efficacy and Tolerability, with Established Development Path
Potential for Greater Efficacy and Tolerability, with Established Development and Regulatory Path Proprietary linker enables efficient delivery of both payloads simultaneously within the tumor cells — minimizing systemic exposure 1 ANTIBODY 1 ▸High affinity antibody with superior internalization ▸Id
Slide 24: Sutro's Cell-Free Platform Enables Site-Selective ADCs
Sutro’s Cell-Free Platform Enables Site-Selective ADCs with Superior Exposure and Design Flexibility Clinical Precedence for Higher ADC DAR12 ADCs Exposure Leading to Better ORR Site combo 4 Payload Adjusted Dose ADC Exposures Site combo 6 Site combo 8 Higher Same Exposure Site combo 15 Payload With
Slide 25: 12.5 mg/kg for 8+4 dpADC vs Highest Reported Dose for DAR4 MMAE ADC
12.5 mg/kg for 8+4 dpADC vs Highest Reported Dose for DAR4 MMAE ADC Area Target Linker Payload DAR NHP HNSTD Highest Clinical Phase Padcev Nectin-4 Val-cit MMAE 4 3 mg/kg1 (Q1Wx4) Approved Tivdak TF Val-cit MMAE 4 3 mg/kg1 (Q3Wx5) Approved SGN-B6A ITGB6 Val-cit MMAE 4 6 mg/kg1 (Q3Wx2) Phase 3 LCB84
Slide 26: Dual-Payload ADCs Have Overcome Resistance and Driven Tumor Regression
Dual-Payload ADCs Have Overcome Resistance and Driven Tumor Regression in Preclinical Models Dual-Payload ADC Induces Tumor Dual-Payload ADCs Have Improved In Vivo Regression After Sequential ADC Resistance Efficacy in an MTI-Resistant CRC Xenograft Model HCT-116 Tumor Growth Curves 10 mg/kg Enhertu
Slide 27: iADC: Dual-Payload ADC Combining Cytotoxin and Immune Stimulator
iADC: Dual-Payload ADC Combining Tumor-Targeted Delivery of a Cytotoxin and Immune Stimulator Strategic partnership with Astellas to deliver new treatment options for cold tumors and patients unresponsive to existing cancer immunotherapies Combining a cytotoxin and immune modulator gives potential t
Slide 28: Leadership Team
Leadership Team Jane Chung, RPh Greg Chow, MBA Hans-Peter Gerber, PhD Chief Executive Officer Chief Financial Officer Chief Scientific Officer Barbara Leyman, PhD David Pauling, JD, MA Venkatesh Srinivasan, PhD Chief Business Officer Chief Administrative Officer and Chief Technical General Counsel O
Slide 29: Pipeline of Next-Generation Single- and Dual-Payload ADCs
Pipeline of Next-Generation Single- and Dual-Payload ADCs PHASE 3/ PROGRAM MODALITY/TARGET INDICATION DISCOVERY PRECLINICAL PHASE 1/1B PHASE 2 REGISTRATIONAL PARTNER WHOLLY-OWNED PROGRAMS STRO-004 Tissue Factor ADC Solid Tumors STRO-006 Integrin αvβ6 Solid Tumors STRO-00X Dual-Payload ADC Solid Tumo
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