Princeton, NJ – May 20, 2024 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, encourages its eligible stockholders to participate in the upcoming Annual Meeting of Stockholders to be held virtually at 9:00AM ET on May 23, 2024. “This Annual Meeting is exceedingly important to the Company,” stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. “We have a number of proposals to be voted on in order to continue to provide value to our stockholders and advance our rare disease pipeline forward, including our confirmatory Phase 3 study with HyBryte™ for the treatment of cutaneous T-cell lymphoma (CTCL).”

Only stockholders at the close of business on the record date, April 10, 2024 will be eligible to participate. Even stockholders as of April 10, 2024 who have subsequently sold their shares are eligible and encouraged to vote. While voting via the Internet and by phone before the meeting will be open until May 22, 2024 at 11:59 PM ET, we encourage eligible stockholders to vote as early as possible to ensure their vote is counted.

Eligible stockholders may vote their shares via the Internet, telephone or mail:

• Go to www.proxyvote.com and follow the instructions (have your proxy card available)
• Call 1-800-690-6903 and follow the voice prompts (have your proxy card available)
• If you have received a proxy card, mark your vote, sign your name exactly as it appears on your proxy card, date your card and return it in the envelope provided

Please refer to the official proxy filing for further details on each proposal, this can be found at https://ir.soligenix.com/sec-filings.

About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our Specialized BioTherapeutics business segment is developing and moving toward potential commercialization of HyBryte™ (SGX301 or synthetic hypericin sodium) as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma (CTCL). With successful completion of the second Phase 3 study, regulatory approvals will be sought to support potential commercialization worldwide. Development programs in this business segment also include expansion of synthetic hypericin (SGX302) into psoriasis, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of inflammatory diseases, including oral mucositis in head and neck cancer, and (SGX945) in Behçet's Disease.

Our Public Health Solutions business segment includes development programs for RiVax^®, our ricin toxin vaccine candidate, as well as our vaccine programs targeting filoviruses (such as Marburg and Ebola) and CiVax™, our vaccine candidate for the prevention of COVID-19 (caused by SARS-CoV-2). The development of our vaccine programs incorporates the use of our proprietary heat stabilization platform technology, known as ThermoVax^®. To date, this business segment has been supported with government grant and contract funding from the National Institute of Allergy and Infectious Diseases (NIAID), the Defense Threat Reduction Agency (DTRA) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at https://www.soligenix.com and follow us on LinkedIn and Twitter at @Soligenix_Inc.