Soligenix Appoints Former White House Economic Adviser Tomas J. Philipson, PhD as Strategic Advisor

PRINCETON, N.J.,Sept. 23, 2025 /PRNewswire/ — 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, announced today the appointment of Tomas J. Philipson, PhD as a Strategic Advisor.

Dr. Philipson is a leading expert in U.S. economic policy, particularly health care policy, and is a frequent commentator on major media outlets, including Forbes, The Economist, The Wall Street Journal, the New York Times, CNN, BBC, CBS, ABC, CNBC, Fox News, Fox business, newsmax, Yahoo Finance, american Voice, bloomberg, and CSPAN.

Currently, Dr. Philipson serves as Managing Partner of the venture capital firm MEDA Ventures, holds positions on several corporate boards, and has co-founded companies like Precision Health Economics LLC, which was acquired by Blackstone in 2015.

His government experience includes serving as vice chairman and acting chairman of President TrumpS White House Council of Economic Advisers from 2017 to 2020.He also previously advised the heads of the U.S. Food and Drug Administration (FDA) and the Centers for Medicare and Medicaid Services (CMS) in senior economic roles. Dr. Philipson was appointed to the Key Indicator Commission by the Speaker of the House of Representatives in 2012 and served as a scientific advisor to the House of Representatives initiative 21st Century Cures in 2015 and the Biden Cancer Initiative in 2017. He also advised Senator John McCain’s 2008 presidential campaign.

Dr. Philipson is a highly decorated academic, having been a chaired professor at the University of Chicago and receiving numerous research awards, including two Arrow Awards from The International Health economics Association, the Garfield Award for Economic Research, the Prêmio Haralambos Simeonidis from the Brazilian Economic Association, and the Milken Institute’s Distinguished economic Research Award. He holds a BA in mathematics from Uppsala University in Sweden and an MA in Mathematics from Claremont Graduate University.

## HyBryte™ Demonstrates Promising Results in CTCL Treatment and Advances to Second Phase 3 Trial

HyBryte™ has shown significant efficacy and a strong safety profile in a recently completed Phase 3 study for the treatment of cutaneous T-cell Lymphoma (CTCL). The initial treatment cycle demonstrated a substantial reduction in lesions among patients receiving HyBryte™ – at least 50% – compared to just 4% in the placebo group (p=0.04), as measured by the CAILS score. This treatment was also safe and well-tolerated.

Further analysis in a second,open-label cycle (Cycle 2) revealed a 40% response rate in patients treated with HyBryte™ for 12 weeks (p<0.0001 vs. placebo in Cycle 1). A statistically significant improvement was also observed when comparing 12-week versus 6-week treatment durations (p<0.0001),highlighting the benefits of continued treatment. HyBryte™ proved equally effective against both plaque (42%, p<0.0001 vs. placebo) and patch (37%, p=0.0009 vs. placebo) lesions, addressing a key challenge in CTCL treatment - the difficulty in managing plaque lesions. An optional third cycle (Cycle 3) focused on safety, with 66% of patients electing to continue treatment. Among those treated with HyBryte™ throughout all three cycles, 49% showed a positive response (p<0.0001 vs. placebo in Cycle 1). Importantly, the study confirmed minimal systemic absorption of HyBryte™, reinforcing its favorable safety profile. The treatment remained well-tolerated even with extended and increased use. HyBryte™'s safety is a key differentiator,as its mechanism of action does not involve DNA damage,unlike currently available therapies which carry risks of melanoma,malignancies,and significant skin damage. existing treatments are typically reserved for patients who have failed other therapies, leaving a need for a safe and effective front-line option. HyBryte™ potentially fills this gap. Following positive feedback from the FDA and EMA, a second confirmatory Phase 3 trial, FLASH2, is planned to begin before the end of 2024. This randomized,double-blind,placebo-controlled,multicenter study will enroll approximately 80 patients with early-stage CTCL. FLASH2 will replicate the successful design of the first Phase 3 FLASH study, but will extend the double-blind, placebo-controlled assessment to 18 weeks of continuous treatment, with the primary endpoint assessment at the end of this period.

Soligenix Announces Progress with Clinical Programs and Funding

PRINCETON, N.J., Sept. 24, 2025 – Soligenix, Inc. (Nasdaq: SGEN) today announced progress across its clinical advancement programs for both its Autoimmune and Infectious disease business segments. The company is currently evaluating dusquetide (SGX942) for inflammatory diseases, including oral mucositis in head and neck cancer patients, and SGX945 in Behçet’s Disease.

Our Public Health Solutions business segment is focused on developing RiVax^®, a ricin toxin vaccine candidate, as well as vaccines targeting filoviruses like Marburg and Ebola.We’re also working on CiVax™, a vaccine candidate to prevent COVID-19 (caused by SARS-CoV-2). We use our ThermoVax^® technology – a special heat stabilization platform – in developing these vaccines.So far, this work has been funded by grants and contracts 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 more data about Soligenix, Inc., please visit our website at https://www.soligenix.com and follow us on LinkedIn and Twitter at @Soligenix_Inc.

This press release includes forward-looking statements about soligenix’s future expectations, including potential market sizes, patient populations, clinical trial enrollment, and the timing and use of funds from our recent offering. Words like “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” and “potential” identify these statements.these statements aren’t guarantees, and actual results could differ significantly due to various risks and uncertainties.