Tonix Pharmaceuticals Holding Corp. · NASDAQ:TNXP

Tonix Pharmaceuticals — World Congress on Vaccines 2025

39 slides from Tonix Pharmaceuticals's conference presentation, Jul 10, 2025

1. Slide 1: TNX-801, A Single-Dose Live Vaccine Platform for Mpox and Other Emerging Viral Diseases

   TNX - 801, A SINGLE - DOSE LIVE VACCINE PLATFORM FOR MPOX AND OTHER EMERGING VIRAL DISEASES: SAFETY, IMMUNOGENICITY, AND EFFICACY Sina Bavari, Ph.D. World Congress on Vaccines July 10 th , 2025 © 2025 Tonix Pharmaceuticals Holding Corp.

2. Slide 2: Disclaimer

   2 © 2025 Tonix Pharmaceuticals Holding Corp. DISCLAIMER "Certain statements in this presentation regarding strategic plans, expectations and objectives for future operations or results are “forward - looking statements” as defined by the Private Securities Litigation Reform Act of 1995 . These state

3. Slide 3: Talk Overview

   TALK OVERVIEW © 2025 Tonix Pharmaceuticals Holding Corp. 1) Background 2) TNX - 801 attenuation in vitro and in vivo 3) TNX - 801 immunogenicity and efficacy in animal models *TNX - 801 is in the pre - IND stage of development and has not been approved for any indication.

4. Slide 4: Poxviruses

   POXVIRUSES » Double stranded DNA, ~128 - 456 kb size » Virions: enveloped, brick - shaped » Size:  220 to 450 nm long î 140 to 260 nm wide î 140 to 260 nm thick » Infect vertebrate or invertebrate hosts » Genus Orthopoxvirus : ▪ Human Pathogens: • VARV: Case fatality rate  30 to 50% • MPXV: Case f

5. Slide 5: Poxviruses: Ubiquitous in the Environment

   POXVIRUSES: UBIQUITOUS IN THE ENVIRONMENT © 2025 Tonix Pharmaceuticals Holding Corp.

6. Slide 6: Monkeypox Virus (Mpox)

   MONKEYPOX VIRUS (MPOX) © 2025 Tonix Pharmaceuticals Holding Corp. » Endemic in Central and West Africa » Two Clades: 1) Clade I (DRC) 2) Clade IIa (West Africa) and IIb (Nigeria) » Human Case Fatality Rate: ▪ Clade I –  11% ▪ Clade IIa –  3% ▪ Clade IIb –  <0.1% » Clade IIb – 2022 Outbreak ▪ 122

7. Slide 7: Variola Virus (Smallpox)

   VARIOLA VIRUS (SMALLPOX) © 2025 Tonix Pharmaceuticals Holding Corp. » Oldest written record –  3,500 years » Oldest sequences –  1,400 years » Human Case Fatality Rate:  30% » 20 th century –  250 to 500 million deaths » Eradication: 1980

8. Slide 8: Edward Jenner - Smallpox Vaccine (1796)

   EDWARD JENNER - SMALLPOX VACCINE (1796) » Jenner observed milkmaids were protected from smallpox, reasoned that infection with an illness similar to smallpox but less deadly could protect one against smallpox ▪ “Cowpox” was the name of a disease in cows that could transfer to humans and cause sores

9. Slide 9: Smallpox Vaccines

   SMALLPOX VACCINES © 2025 Tonix Pharmaceuticals Holding Corp. » Vaccine: Cowpox origin » Serial passaging: Humans, cows, and horses (143 years) » Vaccine: Vaccinia Virus (1939) closely related to cowpox but serologically distinct 1 » Multiple Vaccinia virus - based vaccines developed » Smallpox eradi

10. Slide 10: Balance of Tolerability and Reactogenicity for Pox-Based Vaccines

    BALANCE OF TOLERABILITY AND REACTOGENICITY FOR POX - BASED VACCINES Well tolerated, Requires high dose, 2 vaccinations ~1 death per million ~10 deaths per million Non - propagating © 2025 Tonix Pharmaceuticals Holding Corp. Robustly Propagating Dryvax Lister TianTan Copenhagen Tashkent MVA NYVAC Can

11. Slide 11: Balance of Tolerability and Reactogenicity for Pox-Based Vaccines

    BALANCE OF TOLERABILITY AND REACTOGENICITY FOR POX - BASED VACCINES Well tolerated, Requires high dose, 2 vaccinations ~1 death per million ~10 deaths per million Non - propagating © 2025 Tonix Pharmaceuticals Holding Corp. Robustly Propagating Dryvax Lister TianTan Copenhagen Tashkent MVA NYVAC Can

12. Slide 12: Prong Approach to Mpox/Smallpox Vaccine

    4 PRONG APPROACH TO MPOX/SMALLPOX VACCINE (TNX - 801) © 2025 Tonix Pharmaceuticals Holding Corp. 1) Well - tolerated 2) Single dose 3) Durable 4) Protection against mpox disease (lesions)

13. Slide 13: Attenuation In Vitro and In Vivo

    TNX - 801 ATTENUATION IN VITRO AND IN VIVO © 2025 Tonix Pharmaceuticals Holding Corp.

14. Slide 14: In Vitro Attenuation

    IN VITRO ATTENUATION OF TNX - 801 © 2025 Tonix Pharmaceuticals Holding Corp. » Investigate attenuation of TNX - 801 in vitro relative to VACV strains ▪ Positive Control: VACV - Western Reserve (WR) , VACV - International Health Department (IHD) ▪ Older vaccines used in smallpox eradication: 1) VACV

15. Slide 15: Displays Small Plaque Phenotype

    TNX - 801 DISPLAYS SMALL PLAQUE PHENOTYPE VACCINA VIRUSES VACV - Western Reserve (WR) VACV - International Health Department (IHD) VACV - Lister (Lis) VACV - New York City Board of Health (NYCBH) TNX - 801 MVA © 2025 Tonix Pharmaceuticals Holding Corp.

16. Slide 16: Replication in Primary Human Cells (Dermal Tract)

    TNX - 801: REPLICATION IN PRIMARY HUMAN CELLS (DERMAL TRACT) Plaque Assay qPCR TNX - 801:  27 - to 119 - fold more attenuated than VACV based vaccines VACV - Western Reserve (WR) VACV - International Health Department (IHD) VACV - Lister (Lis) VACV - New York City Board of Health (NYCBH) TNX - 801

17. Slide 17: In Vivo Attenuation

    IN VIVO ATTENUATION OF TNX - 801 » Investigate attenuation of TNX - 801 in vivo relative to VACV based vaccines ▪ Immunocompromised Mice (C57BL/6 ifnar - / - , C57BL/6 ifngr - / - , C57BL/6 ifnar - / - /ifngr - / - ) • Interferon receptor knockout model • Sensitive to virus infection ▪ Positive Cont

18. Slide 18: Lacks Lethality Associated with Older Smallpox Vaccine Strains

    TNX - 801 LACKS LETHALITY ASSOCIATED WITH OLDER SMALLPOX VACCINE STRAINS (LIS, NYCBH) TNX - 801*, Mock ~3 x 10 8 PFU VACV - Lis, NYCBH ~10 4 and 10 3 PFU VACV - WR, IHD ~10 3 PFU TNX - 801 is up to 100,000 - fold more attenuated © 2025 Tonix Pharmaceuticals Holding Corp.

19. Slide 19: Infection Displays Limited Replication

    TNX - 801 INFECTION DISPLAYS LIMITED REPLICATION VACV - IHD ~10 6 PFU ( ) VACV - NYCBH ~10 6 PFU ( ) TNX - 801 ~10 8 PFU ( ) © 2025 Tonix Pharmaceuticals Holding Corp.

20. Slide 20: Highly Attenuated with Improved Safety Profiles Compared to Other Vaccinia-Based Vaccines

    TNX - 801 IS HIGHLY ATTENUATED WITH IMPROVED SAFETY PROFILES COMPARED TO OTHER VACCINA - BASED VACCINES © 2025 Tonix Pharmaceuticals Holding Corp.

21. Slide 21: Immunogenicity and Efficacy in Animal Models (Single Dose)

    TNX - 801 IMMUNOGENICITY AND EFFICACY IN ANIMAL MODELS (SINGLE DOSE) 1) 2) 3) © 2025 Tonix Pharmaceuticals Holding Corp.

22. Slide 22: NHP Immunogenicity and Efficacy Study Design

    NHP IMMUNOGENICITY AND EFFICACY STUDY DESIGN rVACV = Plaque pick from ACAM2000 (Approved Vaccine) © 2025 Tonix Pharmaceuticals Holding Corp.

23. Slide 23: NHP Immunogenicity: Induces Neutralizing Antibody Response

    NHP IMMUNOGENICITY: TNX - 801 INDUCES NEUTRALIZING ANTIBODY RESPONSE © 2025 Tonix Pharmaceuticals Holding Corp.

24. Slide 24: Provides Protection Against Mpox Disease

    TNX - 801 PROVIDES PROTECTION AGAINST MPOX DISEASE NO LESIONS in TNX - 801 vaccinated groups © 2025 Tonix Pharmaceuticals Holding Corp.

25. Slide 25: Provides Protection Against Lethal Monkeypox Clade I Challenge

    TNX - 801 PROVIDES PROTECTION AGAINST LETHAL MONKEYPOX CLADE I CHALLENGE NO LETHALITY in TNX - 801 vaccinated groups © 2025 Tonix Pharmaceuticals Holding Corp.

26. Slide 26: Vaccination via Alternative Routes (ID, SC, IM): Study Design

    TNX - 801 VACCINATION VIA ALTERNATIVE ROUTES (ID, SC, IM): STUDY DESIGN Number of Animal per Group Dose (PFU) Route Treatment 6 (3M/3F) 10 6 ID TNX - 801 6 (3M/3F) 10 5 ID TNX - 801 6 (3M/3F) 10 6 SC TNX - 801 6 (3M/3F) 10 5 SC TNX - 801 6 (3M/3F) 10 6 IM TNX - 801 6 (3M/3F) 10 5 IM TNX - 801 6 (4M/

27. Slide 27: Immunogenicity: Anti-VACV (MVA) Titers

    IMMUNOGENICITY: DAY 28 ANTI - VACV (MVA) TITERS © 2025 Tonix Pharmaceuticals Holding Corp. LOD Comparable IgG titers regardless of Route or Dose

28. Slide 28: Protects Against Clinical Disease (Lesions)

    TNX - 801 PROTECTS AGAINST CLINICAL DISEASE (LESIONS) NO LESIONS in TNX - 801 vaccinated groups © 2025 Tonix Pharmaceuticals Holding Corp.

29. Slide 29: Protects Against Clinical Disease (Lesions)

    TNX - 801 PROTECTS AGAINST CLINICAL DISEASE (LESIONS) NO LESIONS in TNX - 801 vaccinated groups © 2025 Tonix Pharmaceuticals Holding Corp.

30. Slide 30: Protects Against Lethal RPXV Challenge

    TNX - 801 PROTECTS AGAINST LETHAL RPXV CHALLENGE NO LETHALITY in TNX - 801 vaccinated groups © 2025 Tonix Pharmaceuticals Holding Corp.

31. Slide 31: Protection Against Lethal Monkeypox Clade IIa Challenge: Alternative Routes

    TNX - 801 PROVIDES PROTECTION AGAINST LETHAL MONKEYPOX CLADE IIA CHALLENGE: ALTERNATIVE ROUTES © 2025 Tonix Pharmaceuticals Holding Corp.

32. Slide 32: Protection Against Lethal Monkeypox Clade IIa Challenge: Alternative Routes

    TNX - 801 PROVIDES PROTECTION AGAINST LETHAL MONKEYPOX CLADE IIA CHALLENGE: ALTERNATIVE ROUTES TNX - 801 (PERCUT) TNX - 801 (SC) TNX - 801 (IM) Mock Weight Loss Survival *p <0.0001 *p <0.003 * * * * © 2025 Tonix Pharmaceuticals Holding Corp.

33. Slide 33: Durable Protection Against Lethal Rabbitpox Challenge: 6 Months

    TNX - 801 PROVIDES DURABLE PROTECTION AGAINST LETHAL RABBITPOX CHALLENGE: 6 MONTHS © 2025 Tonix Pharmaceuticals Holding Corp.

34. Slide 34: Durable Protection Against Lethal Rabbitpox Challenge: 6 Months

    TNX - 801 PROVIDES DURABLE PROTECTION AGAINST LETHAL RABBITPOX CHALLENGE: 6 MONTHS © 2025 Tonix Pharmaceuticals Holding Corp.

35. Slide 35: Durable Protection Against Lethal Rabbitpox Challenge: 6 Months

    TNX - 801 PROVIDES DURABLE PROTECTION AGAINST LETHAL RABBITPOX CHALLENGE: 6 MONTHS © 2025 Tonix Pharmaceuticals Holding Corp.

36. Slide 36: Durable Protection Against Lethal Rabbitpox Challenge: 14 Months

    TNX - 801 PROVIDES DURABLE PROTECTION AGAINST LETHAL RABBITPOX CHALLENGE: 14 MONTHS © 2025 Tonix Pharmaceuticals Holding Corp.

37. Slide 37: Safety

    TNX - 801 SAFETY © 2025 Tonix Pharmaceuticals Holding Corp. » In vitro : ▪ Small plaque phenotype ▪ Up to 100 - fold lower replication than VACV strains ▪ Primary cells from dermal and respiratory tracts » In vivo : ▪ Well tolerated in mice, rabbits, hamsters, and NHPs ▪ Minimal or no disease in imm

38. Slide 38: Immunogenicity and Efficacy (Single Dose)

    TNX - 801 IMMUNOGENICITY AND EFFICACY (SINGLE DOSE) © 2025 Tonix Pharmaceuticals Holding Corp. » Evaluated in multiple animal models ▪ Mouse, Rabbit, and NHP (Cynomolgus) » Elicits IgG and/or neutralizing responses ▪ Various route percutaneous, subcutaneous, intramuscular ▪ Microneedle delivery » Pr

39. Slide 39: Acknowledgements

    ACKNOWLEDGEMENTS © 2025 Tonix Pharmaceuticals Holding Corp. » University of Alberta ▪ Ryan Noyce ▪ David Evans » Southern Research » TNX - 801 Team ▪ Scott Goebel ▪ Tinoush Moulaei ▪ Natasza Ziółkowska ▪ Siobhan Fogarty ▪ Helen Stillwell ▪ Bruce Daugherty ▪ Farooq Nasar ▪ Seth Lederman » TNX - 801 T

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