Osivax and GC Biopharma Enter Strategic Collaboration to Develop a Next-Generation Influenza Vaccine Combining OVX836 and GC FLU

• Combines Osivax’s proprietary OVX836 T-cell vaccine and technology with GC Biopharma’s marketed influenza vaccine and worldwide manufacturing expertise
• Positions Osivax as the global development lead for a differentiated next-generation influenza vaccine candidate
• Aims to deliver enhanced and more durable protection against highly mutating seasonal influenza strains

Lyon, France and Yongin, Republic of Korea – 27 August 2026 – Osivax, a clinical-stage biopharmaceutical company developing differentiated influenza vaccines designed to generate broad-spectrum immune responses, and GC Biopharma, a leading South Korean biopharmaceutical company with extensive experience in vaccines and plasma-derived products, today announced a long-term collaboration to develop and commercialize a next-generation seasonal influenza vaccine candidate designed to provide broader and more durable protection against a wide range of influenza strains.

Under the agreement, the companies will develop the combination of OVX836, Osivax’s broad-spectrum influenza A vaccine candidate targeting the highly conserved nucleoprotein (NP), with GC FLU, GC Biopharma’s standard-dose, WHO-prequalified, inactivated seasonal influenza vaccine, in a single injection. The combination is expected to leverage complementary immune mechanisms to provide higher and broader protection against circulating and emerging influenza strains. OVX836 is designed to induce T-cell responses against the highly conserved NP antigen, while GC FLU provides antibody responses against the well-known Hemagglutinin (HA) surface antigen.

The agreement grants Osivax a non-exclusive, sublicensable, global license (excluding Japan and Korea) to use GC FLU in combination with OVX836. Osivax will lead the global development strategy for the combination vaccine candidate and will be responsible for its development and commercialization outside the Republic of Korea, where GC Biopharma will retain exclusive rights. GC Biopharma will receive royalties and ensure long-term supply of GC FLU. Additional details and financial terms have not been disclosed.

“Despite decades of progress in influenza vaccination, there remains a significant need for approaches that can provide broader and more durable protection against evolving influenza strains,” said Alexandre Le Vert, CEO and Co-Founder of Osivax. “This agreement marks a key step towards developing a superior seasonal influenza vaccine by combining Osivax’s T-cell-focused approach with GC Biopharma’s established GC FLU vaccine and manufacturing capabilities. This partnership is a cornerstone of our strategy to lead the development of a next-generation seasonal influenza vaccine while preserving Osivax’s strategic independence.”

“Advancing next-generation influenza vaccines requires collaboration between companies with complementary expertise across various scientific disciplines,” said Eun-Chul Huh, CEO of GC Biopharma. “We are pleased to partner with Osivax to develop a combination vaccine candidate designed to address long-standing unmet needs in seasonal influenza prevention. This agreement supports GC Biopharma’s continued expansion into major advanced markets while reinforcing our domestic position.”

Seasonal influenza remains a significant public health burden, particularly among older adults and people at increased risk of complications. Current seasonal influenza vaccines primarily target surface antigens that can vary substantially from season to season. OVX836 is designed to target NP, a more conserved internal influenza A antigen, with the aim of broadening protection across influenza A strains. Osivax previously reported that co-administration of OVX836 with a seasonal inactivated influenza vaccine was well tolerated and induced complementary immune responses, supporting further development of combination approaches.

About OVX836
OVX836 is a first-in-class influenza A vaccine candidate that targets the nucleoprotein (NP), a highly conserved internal antigen. Unlike surface antigens, the NP is much less likely to mutate, providing a broader and more universal immune response. Osivax’ oligoDOM^TM technology enables the design and production of a recombinant version of the NP, which self-assembles into a nanoparticle, thus triggering powerful T- and B-cell immune responses. OVX836 has been tested in 7 clinical trials with over 4,000 participants so far, and has shown promising safety, immunogenicity, and efficacy read-outs.

About GC FLU
GC FLU is GC Biopharma’s seasonal influenza vaccine. WHO prequalification listings identify GC FLU inj. and GC FLU Multi inj. as current WHO-prequalified seasonal trivalent influenza vaccines manufactured by GC Biopharma Corp. in the Republic of Korea.

About Osivax
Osivax is a clinical-stage biopharmaceutical company developing a portfolio of differentiated influenza vaccines generating superior T-cell responses in addition to strong and sustained B-cell responses, thanks to its novel, self-assembling nanoparticle platform technology, oligoDOM^TM. The company’s lead candidate, OVX836, is a broad-spectrum influenza A vaccine candidate currently in Phase 2b clinical trials with over 4,000 volunteers tested and encouraging efficacy proof of concept data. By combining OVX836 with standard flu vaccines, Osivax is advancing toward a best-in-class seasonal flu vaccine to prevent all strains of influenza. Osivax collaborates with leading global health agencies, including US based BARDA and NIH, and European-based institutions and top-tier pharmaceutical companies, reinforcing its mission to prevent all types of seasonal and pandemic influenza. The company will expand into other infectious disease indications through combinations and collaborations worldwide. For further information: www.osivax.com

About GC Biopharma
GC Biopharma, formerly known as Green Cross Corporation, is a biopharmaceutical company headquartered in Yongin, Republic of Korea. The company has more than half a century of experience in the development and manufacturing of plasma derivatives and vaccines, and is expanding its global presence. GC Biopharma also continues to invest in innovation by leveraging R&D capabilities in protein engineering, mRNA and lipid nanoparticle drug delivery technologies to develop therapeutics in areas including rare diseases and immunology and inflammation.

Contact

Attachment

• Osivax and GC Biopharma Enter Strategic Collaboration to Develop a Next-Generation Influenza Vaccine