Proceeds to support Phase 2-enabling activities for Gamma-PN, including cGMP manufacturing, expansion of the Company's OPA-testing capabilities and planned submission of an IND to the FDA

NEW YORK and ADELAIDE, Australia, Nov. 2, 2026 /PRNewswire/ -- GPN Vaccines, Inc., a clinical-stage biotechnology company developing a new generation of broadly protective bacterial vaccines designed to overcome the limitations of serotype-specific vaccination, today announced the closing of its US$10 million private placement financing with participation from new and existing investors. Proceeds from the financing will support preparations to advance the Company's lead vaccine candidate, Gamma-PN™, into Phase 2 clinical development, including cGMP batch manufacturing, expansion of its opsonophagocytic activity (OPA) testing laboratory, and submission of the Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA).

Gamma-PN is an investigational, serotype-independent pneumococcal vaccine designed to address a fundamental limitation of currently available serotype-specific vaccines. More than 100 serotypes of Streptococcus pneumoniae exist, yet currently available vaccines provide protection against only a subset, requiring manufacturers to continually develop vaccines incorporating additional serotypes. Gamma-PN is designed to generate immune responses against protein antigens shared across all pneumococcal strains, offering the potential to elicit protection independent of capsular serotype.

"For decades, pneumococcal vaccine development has focused on expanding the number of serotypes included in increasingly complex products," said Tim Hirst, Ph.D., Chairman and CEO of GPN Vaccines. "Gamma-PN is designed to take a fundamentally different approach by targeting protein antigens inherent to all pneumococcal strains, with the goal of providing broad protection regardless of serotype. This financing provides the resources to complete key Phase 2-enabling activities and advance a program that we believe could meaningfully expand the possibilities for pneumococcal disease prevention. We are grateful to our existing and new investors for their confidence in our vision."

Gamma-PN has completed four Phase 1 clinical studies demonstrating safety, tolerability and immunogenicity across different adult populations. Additionally, data produced by GPN indicate that Gamma-PN generates functional OPA antibodies in humans capable of bacterial killing across multiple serotypes. OPA has been used as an immunologic endpoint and, in specified contexts, as a surrogate measure in the regulatory evaluation of pneumococcal vaccines. GPN is now preparing for a multinational, randomized, controlled, double‑blinded, dose ranging study to evaluate the safety, tolerability and immunogenicity of a single dose of Gamma-PN in adults aged 50+.

The global pneumococcal vaccine market exceeds $9 billion annually, led by Pfizer's Prevnar^® franchise and Merck's Vaxneuvance^® and Capvaxive^®. Despite decades of innovation, currently marketed vaccines remain limited by their serotype-specific design that requires multivalent manufacturing processes that can add substantial development and supply-chain complexity. Together, these factors create significant opportunity for a broadly protective, elegantly designed vaccine capable of addressing both current and emerging strains.

"The size of the pneumococcal vaccine market reflects both the enormous global disease burden and the value of effective vaccination, yet the industry is still constrained by vaccines that address serotypes individually," said Bruce Forrest, M.D., Ph.D., MBA, Executive Chief Scientific Officer of GPN Vaccines. "Gamma-PN takes a fundamentally different approach. By targeting protein antigens common across pneumococcal strains, it is designed to generate functional immunity broadly across serotypes without requiring each one to be incorporated into the vaccine. As such, we believe Gamma-PN has the potential to upend the current serotype-specific model in a market where the leading vaccine franchise generates approximately $6.5 billion in annual sales."

About Gamma-PN™

Gamma-PN™ is GPN Vaccines' lead investigational pneumococcal vaccine, designed to provide broad, serotype-independent protection against Streptococcus pneumoniae. Unlike conventional vaccines that target selected serotypes, Gamma-PN is designed to generate immune responses against protein antigens common across pneumococcal strains, with the potential to protect against more than 100 existing serotypes as well as those that may emerge in the future. Gamma-PN has completed four Phase 1 clinical studies demonstrating safety, tolerability and immunogenicity, including the generation of functional opsonophagocytic activity (OPA) responses demonstrating activity against multiple pneumococcal serotypes. OPA responses have been used as immunologic endpoints and, in specified contexts, as surrogate measures supporting regulatory approval of pneumococcal vaccines. GPN is preparing to advance Gamma-PN into Phase 2 clinical development.

About GPN Vaccines

GPN Vaccines, Inc. is a clinical-stage biotechnology company developing a new generation of broadly protective bacterial vaccines designed to overcome the limitations of serotype-specific vaccination. The Company's lead candidate, Gamma-PN™, is a potentially disruptive whole-cell pneumococcal vaccine designed to provide broad, serotype-independent protection against Streptococcus pneumoniae, including current and emerging serotypes. Gamma-PN has completed four Phase 1 clinical studies demonstrating safety, tolerability and immunogenicity, and GPN is preparing to advance Gamma-PN into Phase 2 clinical development. Additionally, GPN is building a broader bacterial vaccine pipeline that includes its Gamma-SU program targeting Streptococcus suis and programs targeting non-typeable Haemophilus influenzae and Moraxella catarrhalis through BacVax. For more information, visit www.gpnvaccines.com.

Investor Contact:
Tiberend Strategic Advisors, Inc.
David Irish / Brooke Cooper
+1-231-632-0002 / +1-862-274-1134
dirish@tiberend.com / bcooper@tiberend.com

Media Contact:
Tiberend Strategic Advisors, Inc.
Casey McDonald / Michelle Katsel
+1-646-577-8520 / +1-201-790-3390
cmcdonald@tiberend.com / mkatsel@tiberend.com 

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SOURCE GPN Vaccines, Inc.