Os Therapies Incorporated · AMEX:OSTX
Os Therapies — Investor Presentation (September 2026)
19 slides from Os Therapies's investor presentation, September 2026
Slide 1: Corporate Presentation
Corporate Presentation September 2026 NYSE American: OSTX
Slide 2: Safe Harbor Statement
Safe Harbor Statement This document contains forward-looking statements. In addition, from time to time, we or our representatives may make forward-looking statements orally or in writing. We base these forward-looking statements on our expectations and projections about future events, which we deri
Slide 3: Investment Highlights
Investment Highlights Over $300 million has been invested in listeria platform to date, mostly by Advaxis/Ayala (OS acquired all listeria-based assets in April 2025) Platforms Near-Term Catalytic Milestones Total Addressable Market OST-HER2: Listeria monocytogenes (Lm): Meetings with FDA/MHRA/EMA &
Slide 4: Clinical-Stage Pipeline (Listeria Platform)
Clinical-Stage Pipeline (Listeria Platform) Trial Preclinical Phase 1 Phase 2a Phase 2b Phase 3 Approval Launched ✔ Orphan drug designation Osteosarcoma (OS) Lead (OST-HER2) Positive Phase 2b Data. Targeting Accelerated Approval Q2-Q3/26 ✔ Fast Track Designation ✔ Rare Pediatric Disease Program Desi
Slide 5: Preclinical Pipeline – Silicone Linker tADC Platform
Preclinical Pipeline –Silicone Linker tADC Platform Trial Preclinical Phase 1 Phase 2a Phase 2b Phase 3 Approval Launched Ovarian Cancer (OST-tADC) Breast Cancer (OST-tADC) Other Solid Tumors (OST-tADC) Solid Tumors (8 undisclosed OST-Lm therapeutic candidates) NYSE American: OSTX 5
Slide 6: Management Team - 100+ Years of Experience
Management Team - 100+ Years of Experience Robert Petit, PhD Jutta Wanner, PhD Paul Romness, MHP Gerald Commissiong Chief Medical & Scientific Officer Advisor President & CEO - OS Therapies Chief Business Officer Founding Scientist: OST-HER2 Founding Scientist: OST-tADC • 25 years of experience in t
Slide 7: Scientific Advisory Board for Osteosarcoma
Scientific Advisory Board for Osteosarcoma Peter M. Anderson, MD Meenakshi Hedge, MD Nabil M. Ahmed, MD Assistant Professor, Associate Professor, Department Of Pediatric Department Of Pediatrics, Department Of Pediatrics, Hematology, Oncology And Section Of Hematology - Section Of Hematology- Blood
Slide 8: Advisory Boards, Media and Partnerships
Advisory Boards, Media and Partnerships Antibody Drug Conjugates OS Patient Advocacy Commercialization (ADCs) Miriam Cohen Serena Subada Dr. Jutta Wanner Chris Benecchi Mother of OS Angel Osteosarcoma Patient Founding Scientist Chief Business Officer OST-HER2 Trial Participant Mac Tichenor Olivia Eg
Slide 9: OST-HER2: Osteosarcoma + Other Cancers
OST-HER2: Osteosarcoma + Other Cancers
Slide 10: Osteosarcoma (Bone Cancer)
Osteosarcoma (Bone Cancer) No Treatments Available to Prevent or Delay Subsequent Recurrences Global Death Rate Upon Recurrence/Metastasis Preclinica Phase 1 is 80-90% Phase 2b Crompton et al: Survival after recurrence of osteosarcoma: A 20‐year experience at a single institution. August 2005: Pedia
Slide 11: Mechanism of Action: Immune Activation
Mechanism of Action: Immune Activation 1 2 3 4 5 CD8+ NK MHC I CD4+ NK CD8+ HER2 Helper T NK cell Killer T MHC I MHC II DC TUMOUR Mono DC CELL L. monocytogenes (Lm) Attenuated Macro- phage Monocyte Dendritic cell HER2-tLLO payload HER2 peptide Treg MDSC The Construct Trojan Horse Entry Peptide-MHC A
Slide 12: OST-HER2 Open Label Phase 2b Trial
OST-HER2 Open Label Phase 2b Trial Enrollment Criteria • 12-39 years old • Recurred, resected metastatic (METS) Osteosarcoma • 39 evaluable patients at 21 centers, single treatment arm – FULL TREATMENT ARM COMPLETE • 52 Weeks on Study: Dosed 16 times every 3 weeks for 48 weeks with 4-week follow-up
Slide 13: OST-HER2: Interim 3-Year Overall Survival Data vs. Historical Control
OST-HER2: Interim 3-Year Overall Survival Data vs. Historical Control 71.2% Overall Survival for OST-HER2 vs. 45.8% for historical control (p=0.002)
Slide 14: OST-HER2 Clinical Data in Recurrent, Resected Metastatic Osteosarcoma
OST-HER2 Clinical Data in Recurrent, Resected Metastatic Osteosarcoma OST-HER2 Treated Group (n=41) Published Historical Control (n=42) P-Value Primary Endpoint:12-month EFS 35% (n = 40 evaluable, 1 lost to follow-up) 20% 0.0196 Interim Secondary Endpoint: 3-year OS 71.8% (n = 35 evaluable, 5 lost t
Slide 15: OST-HER2 Regulatory Strategy
OST-HER2 Regulatory Strategy Next Steps • Continued monitoring of overall survival for continued separation • U.K. MHRA and EMA have accepted historical control as comparator • FDA risk/benefit analysis being updated based upon recent Type C Meeting to include pending final 3-year OS data • U.K. MHR
Slide 16: OST-HER2 Additional Cancer Clinical Targets
OST-HER2 Additional Cancer Clinical Targets Solid Tumor Treatment Potential – Combined $20B +TAM HER2 positivity across cancers: analysis of 37,992 samples by HER2+ Solid Tumors1 IHC. IHC 3+ was considered HER2 IHC positive Bladder, Breast Cancer, other HER2+ solid tumors OST-HER2 plus trastuzumab m
Slide 17: OST-Lm Platform Additional Immunotherapy Candidates
OST-Lm Platform Additional Immunotherapy Candidates Solid Tumor Treatment Potential – Combined $35B TAM OST-AXAL (HPV Cancers) • AIM2SERV Trial Completed: 1st of 2 Phase 3 clinical trials needed for approval • Phase 3a trial completed • Phase 3b trial OST-503 (NSCLC & Glioblastoma) • Positive NSCLC
Slide 18: Key Takeaways
Key Takeaways Catalyst Rich Advanced OST-HER2 Cancer Therapeutic Platform Preclinica Phase 1 Phase 2b l Multiple Near-Term Clinical Significant Market Favorable Regulatory Experienced, Successful Milestones Opportunity Review Process Leadership • Phase 2b trial for OST-HER2 in • TAM Human Osteosarco
Slide 19: Thank You!
Thank You! Investor Relations Harrison Seidner, PhD WaterSeid Partners OSTX@waterseid.com Paul Romness President & CEO Public Relations par@ostherapies.com Stephanie Chen (703) 541-9811 Elev8 New Media stephanie@elev8newmedia.com
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