Os Therapies Incorporated · AMEX:OSTX
Os Therapies — Investor Presentation (October 2025)
28 slides from Os Therapies's investor presentation, Oct 17, 2025
Slide 1: Corporate Presentation October 2025
NYSE American: OSTX Corporate Presentation October 2025
Slide 2: Safe Harbor Statement
NYSE American: OSTX 2 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 abou
Slide 3: Investment Highlights
NYSE American: OSTX 3 OS $1.2B Breast Cancer $35B Cancer Immunotherapy $126B Investment Highlights Over $300 million has been invested in listeria platform to date, mostly by Advaxis/Ayala (OS acquired all listeria - based asset s in April 2025) Platforms Total Addressable Market Near - Term Catalyt
Slide 4: Clinical-Stage Pipeline (Listeria Platform)
NYSE American: OSTX 4 Clinical - Stage Pipeline (Listeria Platform) Trial Preclinical Phase 1 Phase 2a Phase 2b Phase 3 Approval Launched Osteosarcoma (OS) (OST - HER2) HPV Cancers (OS) (OST - AXLA) Non - Small Cell Lung Cancer* (NSCLC) (OST - 503) Non - Small Cell Lung Cancer* (NSCLC) (OST - 503) G
Slide 5: Preclinical Pipeline (Listeria & ADC Platform)
NYSE American: OSTX 5 Preclinical Pipeline (Listeria & ADC Platform) 5 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)
Slide 6: Human & Canine Osteosarcoma + Other Human Cancers
OST - HER2: Human & Canine Osteosarcoma + Other Human Cancers
Slide 7: Scientific Advisory Board for Osteosarcoma
NYSE American: OSTX 7 Department Of Pediatric Hematology, Oncology And Blood & Marrow Transplantation Peter M. Anderson, MD Scientific Advisory Board for Osteosarcoma Assistant Professor, Department Of Pediatrics, Section Of Hematology - Oncology, Baylor College Of Medicine Meenakshi Hedge, MD Assoc
Slide 8: Commercialization and Partnerships
NYSE American: OSTX 8 Commercialization and Partnerships OS Patient Advocacy Antibody Drug Conjugates (ADCs) Commercialization Miriam Cohen Mother of OS Angel Serena Subada Osteosarcoma Patient Mac Tichenor Father of OS Angel Olivia Egge Osteosarcoma Patient Tony Trent Father of OS Angel OST - HER2
Slide 9: Osteosarcoma: No Treatments to Prevent or Delay Recurrences
NYSE American: OSTX 9 9 Preclinica l Phase 1 Phase 2b Osteosarcoma (Bone Cancer) No Treatments Available to Prevent or Delay Subsequent Recurrences Global Death Rate Upon Recurrence/Metastasis is 80 - 90% Crompton et al: Survival after recurrence of osteosarcoma: A 20 - year experience at a single i
Slide 10: Osteosarcoma Micro-Metastasis
NYSE American: OSTX 10 Preclinica l Phase 1 Phase 2b Osteosarcoma Micro - Metastasis Lymphocytes (T - Cells) OST - HER2 leverages antigen presentation to drive attack on metastases
Slide 11: Open Label Phase 2b Trial
NYSE American: OSTX 11 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 w
Slide 12: Clinical Data in Recurrent, Resected Metastatic Osteosarcoma
P - Value Published Historical Control (n=42) OST - HER2 Treated Group (n=41) 0.0196 20% 35% (n = 40 evaluable, 1 lost to follow - up) Primary Endpoint:12 month EFS <0.0001 40% 75% (n = 36 evaluable, 5 lost to follow - up) Secondary Endpoint: 2 - year OS 100% Subgroup: OS in =>12month EFS 59% Subgro
Slide 13: Canine Osteosarcoma Program
NYSE American: OSTX 13 OST - HER2 Canine Osteosarcoma Program University of Pennsylvania Veterinary School (UPenn Vet) Regulatory Pathway Positive proof - of - concept data post - resection: Published • Able to distinguish responders with biomarkers • Treatment response, as measured by immune marker
Slide 14: Breast Cancer Treatment: Positive Preclinical & Phase 1 Results
NYSE American: OSTX 14 OST - HER2 Breast Cancer Treatment Positive Preclinical & Phase 1 Results > Anticipate 2025 Phase 2 Trial – $30B TAM Preclinical Studies • In nonclinical studies, OST31 - 164 was found to cause regression of tumors in both a spontaneous HER2 - expressing tumor model and in a m
Slide 15: Animal Data: Inhibition of Growth of Breast Cancer Tumors
NYSE American: OSTX 15 Animal Data: Inhibition of Growth of Breast Cancer Tumors Treatment Model Mouse Models of Breast Cancer • The first figure on the right is a treatment model • The second figure on the right is a prevention model The first figure shows Lm - LLO - chHER2 (OST - HER2 component) A
Slide 16: Combination with HER2 Antibody Shows Stronger Efficacy
NYSE American: OSTX 16 The Combination of OST - HER2 + HER2 Antibody (e.g. Herceptin, et al) shows strong improvement vs. HER2 Antibody alone (PBS + HER2 Ab) * Lm - LLO - (XXX) = OST - HER2 component OST - HER2+ HER - 2/neu Ab Combo Shows Stronger Efficacy Than HER - 2/neu Ab Alone
Slide 17: Suppression of Growth of Metastatic Breast Cancer in the Brain
NYSE American: OSTX 17 Suppression of Growth of Metastatic Breast Cancer in the Brain Delay of Breast Cancer Growth in the Brain To determine whether OST - could inhibit the growth of a metastatic breast cancer in the brain, BALB/c mice (n=4 animals/ group) were administered 5 × 10^8 CFU of OST - HE
Slide 18: Additional Cancer Clinical Targets
NYSE American: OSTX 18 OST - HER2 Additional Cancer Clinical Targets Bladder, Breast Cancer, other HER2+ solid tumors OST - HER2 plus trastuzumab may prevent development of trastuzumab resistance in HER2+ solid tumors like Bladder, Breast, others https://doi.org/10.1016/S1470 - 2045(07)70190 - 0 Sol
Slide 19: OST-Lm Platform Additional Immunotherapy Candidates
NYSE American: OSTX 19 OST - Lm Platform Additional Immunotherapy Candidates • AIM2SERV Trial Completed: 1st of 2 Phase 3 clinical trials needed for approval • Phase 3a trial completed • Phase 3b trial Solid Tumor Treatment Potential – Combined $35B TAM OST - AXAL (HPV Cancers) • Positive NSCLC data
Slide 20: OST-tADC Linker Platform
NYSE American: OSTX 20 OST - tADC Linker Platform tADCs / tSM - DCs /tmRNA - DCs
Slide 21: OST-tADC Product Overview
NYSE American: OSTX 21 OST - tADC Product Overview • “Plug & Play” - Targeting Ligands, pH sensitive SiLinkersTM (silicon linkers), and multiple CAPed (Conditionally Active) Payloads • Antibodies (ADC), small molecules (SM - DC) and mRNA therapeutics (mRNA - DC) Potential to Displace Legacy Cancer C
Slide 22: OST-tADC Platform Is Plug and Play and Adaptable
NYSE American: OSTX 22 OST - tADC PLATFORM IS “PLUG AND PLAY” AND “ADAPTABLE” Modular Approach is a Key Differentiator - Preferred Building Block Examples
Slide 23: Chemical Modifiers Allow Tunable SiLinkers Cleavage
NYSE American: OSTX 23 CHEMICAL MODIFIERS ALLOW TUNABLE SiLINKERS CLEAVAGE Payload Release can be Tuned to Occur Either in Endosome or Lysosome Key Points: • Proximal functional groups influence the hydrolysis rate of the silicone linkers • We have demonstrated that rapid hydrolysis with the pyrimid
Slide 24: tADC Patented Silicon Linkers Design
NYSE American: OSTX 24 tADC Patented Silicon Linkers Design Patented OST SiLinker Pioneering Next - Gen ADCs Next - Gen Silicone LINKER Traditional GGFG LINKER Traditional VAL - CIT LINKER +++ + + % Payload at Released at Target Tumor Site YES Limited NO Stability in Circulation YES NO NO New IP for
Slide 25: Corporate Overview
Corporate Overview
Slide 26: Management Team - 100+ Years of Experience
NYSE American: OSTX 26 Paul Romness, MHP President & CEO - OS Therapies Robert Petit, PhD Chief Medical & Scientific Officer Founding Scientist: OST - HER2 Jutta Wanner, PhD Advisor Founding Scientist: OST - tADC Gerald Commissiong Chief Business Officer Management Team - 100+ Years of Experience De
Slide 27: Key Takeaways
NYSE American: OSTX 27 Preclinica l Phase 1 Phase 2b Key Takeaways Catalyst Rich Advanced OST - HER2 Cancer Therapeutic Platform • Phase 2b trial for OST - HER2 in Osteosarcoma positive data: Announced Jan 2025 • Path to Pivotal OST - HER2 Canine OS study to support full approval pending USDA alignm
Slide 28: Thank You!
Thank You! Paul Romness President & CEO par@ostherapies.com (703) 541 - 9811 Investor Relations Harrison Seidner, PhD WaterSeid Partners OSTX@waterseid.com Public Relations Stephanie Chen Elev8 New Media stephanie@elev8newmedia.com