SNGX

PRINCETON, N.J., Aug. 7, 2026 /PRNewswire/ -- Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today its recent updates and financial results for the quarter ended June 30, 2026. "While we were disappointed with the outcome of the Phase 3 FLASH2 clincial study that led to discontinuing the HyBryte™ (synthetic hypericin) development program, this outcome does not diminish the strength of our broader pipeline or the strategic value of Soligenix," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "We remain focused on evaluating opportunities across our diversified portfolio, including the continued advancement of SGX945 (dusquetide) for Behçet's disease, which demonstrated promising preliminary efficacy and was generally safe and well-tolerated in our Phase 2 study, as well as our ThermoVax® heat-stable vaccine platform." "With approximately $9.8 million in cash as of June 30, 2026, providing cash runway into the second quarter of 2028, we are well positioned to actively evaluate all strategic options to maximize stockholder value, including but not limited to partnerships, licensing opportunities, merger and acquisition opportunities, government grants and contracts, and the advancement of our existing pipeline. Maintaining our Nasdaq listing is also an important strategic asset that supports these efforts by preserving access to the public capital markets, enhancing our attractiveness to potential strategic partners and acquirers, and providing additional flexibility as we evaluate these opportunities. Consistent with this strategy, we are contuning to seek non-dilutive funding support for the development of our heat-stable Bundibugyo Ebola vaccine program from various sources, including the Coalition for Epidemic Preparedness Innovations (CEPI) and others." Soligenix Recent Updates On June 8, 2026, the Company announced that along with the University of Hawaiʻi at Mānoa, it would be applying for CEPI funding to develop a protein-based, thermostable vaccine targeting the Bundibugyo virus by leveraging the thermostability, immunogenicity, and efficacy data demonstrated with its filovirus vaccines. To view this press release, please click here. On May 26, 2026, in response to a recent Bundibugyo virus outbreak in the Congo, the Company highlighted previous work with the University of Hawaiʻi, which has demonstrated platform compatibility with the key Bundibugyo virus antigen enabling rapid development of a protein-based thermostable subunit vaccine. To view this press release, please click here. Financial Results – Quarter Ended June 30, 2026 Soligenix had no revenue for the quarter ended June 30, 2026 and 2025, respectively. Soligenix's net loss was $2.0 million, or ($0.12) per share, for the quarter ended June 30, 2026, compared to $2.7 million, or ($0.82) per share, for the same prior year period. This decrease in net loss was primarily due to a decrease in in research and development expenses associated with the terminated FLASH2 trial and related HyBryte™ development activities. Research and development expenses were $1.0 million as compared to $1.7 million for the quarter ended June 30, 2026 and 2025, respectively. The decrease was primarily due to decreases in costs associated with the terminated FLASH2 trial and related HyBryte™ development activities. General and administrative expenses were $1.1 million for the quarter ended June 30, 2026 as compared to $1.1 million for the same period in 2025, relatively flat with a de minimis increase. As of June 30, 2026, the Company's cash position was approximately $9.8 million. About Soligenix, Inc. Soligenix is a 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 synthetic hypericin for the treatment of psoriasis (SGX302), and our first-in-class Innate Defense Regulator (IDR) technology, dusquetide, for the treatment of inflammatory diseases, including aphthous ulcers in Behçet's Disease (BD) (SGX945) and oral mucositis in head and neck cancer (SGX942). We were developing HyBryte™ (SGX301 or synthetic hypericin sodium), a photodynamic therapy utilizing visible light, for the treatment of cutaneous T-cell lymphoma (CTCL) in a Phase 3 study called "FLASH2" (Fluorescent Light Activated Synthetic Hypericin 2). The Data Monitoring Committee completed its interim efficacy analysis of the FLASH2 trial during April 2026, and under the terms of the interim analysis, the study was recommended to halt for futility. In June 2026, following a thorough review of the Data Monitoring Committee's recommendation and evaluation of the program's path forward, our Board of Directors determined that it was in our best interest and the interest of our stockholders to terminate the HyBryte™ development program. 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 X at @Soligenix_Inc. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements, and include the expected timing and results of clinical trials and the expected timing of regulatory submissions and approvals. The Company's submission of an application for funding from CEPI for Bundibugyo virus vaccine development is preliminary in nature and there can be no assurance that CEPI will select the Company's application for funding, that the Company will receive any funding from CEPI, or that any such funding, if received, will be sufficient to advance the Company's vaccine development programs. The Company does not intend to provide updates regarding the status of its CEPI application unless and until a material development occurs, such as the receipt of a funding award. The failure to receive CEPI funding would not, standing alone, constitute a material event requiring further disclosure, as the Company has not previously received the CEPI funding and would not be losing an existing funding source. In light of the discontinuation of the FLASH2 study, the Company's ability to continue as a going concern will be dependent upon its ability to develop and commercialize its remaining pipeline assets, including dusquetide for the treatment of Behçet's Disease, to identify and acquire or in-license additional product candidates or technologies, and to raise sufficient capital to fund such development and any such acquisitions. There can be no assurance that the Company will be able to obtain financing on acceptable terms, if at all, that suitable acquisition or in-licensing opportunities will be available, or that any of its remaining or future development programs will be successful. If the Company is unable to raise sufficient capital or otherwise advance its remaining assets, it may be required to significantly curtail or cease its operations, sell or otherwise dispose of its assets, or pursue dissolution and liquidation. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/soligenix-announces-recent-updates-and-second-quarter-2026-financial-results-302845724.html

PRINCETON, N.J., May 8, 2026 /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 its recent updates and financial results for the quarter ended March 31, 2026. "We remain disappointed with the unanticipated outcome of the FLASH2 (Fluorescent Light Activated Synthetic Hypericin 2) study," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "Despite the fact that HyBryte™ (synthetic hypericin) demonstrated statistically significant reductions in cutaneous T-cell lymphoma (CTCL) lesions after 6 weeks treatment in the first FLASH study, a similar signal was not observed with 18 weeks of treatment in this study. Over the coming weeks, we will analyze the data to better determine why the study did not meet expectations. If there is any clarity gained from further analysis of the dataset, especially with respect to specific subsets of patients that may benefit from HyBryte™ therapy, then we intend to communicate our findings and explore follow-up discussions with the European Medicines Agency (EMA) and the Food and Drug Administration (FDA)." With approximately $6.0 million in cash at March 31, 2026, and cash runway into the 2nd quarter of 2027, we will evaluate all strategic options moving forward, including but not limited to merger and acquisition opportunities, and the potential of advancing SGX945 (dusquetide) for the treatment of Behçet's Disease, which demonstrated promising biological efficacy in a Phase 2 study last year while most recently receiving orphan drug designation from EMA and Promising Innovative Medicine (PIM) designation from the United Kingdom Medicines and Healthcare Products Regulatory Agency (MHRA). In December, we announced the extended results of the Phase 2a trial of SGX302 (synthetic hypericin) for the treatment of mild-to-moderate psoriasis where SGX302 gel therapy was well tolerated by all patients with no drug related adverse events identified. With the completion of the pilot study, we have laid the groundwork for a more detailed evaluation in this large underserved market. Soligenix Recent Updates On April 28, 2026, the Company announced that the Data Monitoring Committee completed the interim efficacy analysis of its pivotal Phase 3 FLASH2 trial evaluating HyBryte™ in the treatment of CTCL and recommended the study halt for futility. To view this press release, please click here. On April 2, 2026, the Company announced that the positive results of its comparability study evaluating HyBryte™ versus Valchlor® (mechlorethamine) for the treatment of CTCL have been published in Oncology and Therapy. To view this press release, please click here. Financial Results – Quarter Ended March 30, 2026 Soligenix had no revenue or related costs for the quarter ended March 31, 2026 and 2025, respectively. Soligenix's net loss was $2.8 million, or ($0.28) per share, for the quarter ended March 31, 2026, compared to $3.0 million, or ($0.97) per share, for the same prior year period. This decrease in net loss was primarily due to a decrease in operating expenses. Research and development expenses were $1.8 million as compared to $1.9 million for the quarter ended March 31, 2026 and 2025, respectively. The decrease was primarily due to decreases in costs associated with third-party manufacturing, the completed Phase 2 study in BD and site initiation fees for the second confirmatory Phase 3 CTCL trial, partially offset by an increase in patient fees for the second confirmatory Phase 3 CTCL trial. General and administrative expenses were $1.1 million for the quarter ended March 31, 2026 as compared to $1.1 million for the same period in 2025, relatively flat with a de minimis increase. As of March 31, 2026, the Company's cash position was approximately $6.0 million. About Soligenix, Inc. Soligenix is a 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 synthetic hypericin for the treatment of psoriasis (SGX302), and our first-in-class Innate Defense Regulator (IDR) technology, dusquetide, for the treatment of inflammatory diseases, including aphthous ulcers in Behçet's Disease (BD) (SGX945) and oral mucositis in head and neck cancer (SGX942). We were developing HyBryte™ (SGX301 or synthetic hypericin sodium), a photodynamic therapy utilizing visible light, for the treatment of cutaneous T-cell lymphoma (CTCL) in a Phase 3 study called "FLASH2" (Fluorescent Light Activated Synthetic Hypericin 2). The Data Monitoring Committee completed its interim efficacy analysis of the FLASH2 trial during April 2026, and under the terms of the interim analysis, the study was recommended to halt for futility. We are in the process of analyzing the data to better determine why the study did not meet expectations. 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 X at @Soligenix_Inc. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements, and include the expected timing and results of clinical trials and the expected timing of regulatory submissions and approvals. In light of the discontinuation of the FLASH2 study, the Company's ability to continue as a going concern will be dependent upon its ability to develop and commercialize its remaining pipeline assets, including dusquetide for the treatment of Behçet's Disease, to identify and acquire or in-license additional product candidates or technologies, and to raise sufficient capital to fund such development and any such acquisitions. There can be no assurance that the Company will be able to obtain financing on acceptable terms, if at all, that suitable acquisition or in-licensing opportunities will be available, or that any of its remaining or future development programs will be successful. If the Company is unable to raise sufficient capital or otherwise advance its remaining assets, it may be required to significantly curtail or cease its operations, sell or otherwise dispose of its assets, or pursue dissolution and liquidation. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded study response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, notwithstanding any prior observations regarding such blinded response rate, the second HyBryte™ (SGX301) Phase 3 clinical trial did not demonstrate sufficient efficacy at the interim analysis to support continuation of the study, and no assurance can be given that any further development of HyBryte™ (SGX301) will be pursued or that a marketing authorization from the FDA or EMA will be sought or granted. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/soligenix-announces-recent-updates-and-first-quarter-2026-financial-results-302766364.html

PRINCETON, N.J., April 28, 2026 /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 that the Data Monitoring Committee completed the interim efficacy analysis of its pivotal Phase 3 FLASH2 (Fluorescent Light Activated Synthetic Hypericin 2) trial evaluating HyBryte™ (Synthetic Hypericin) in the treatment of cutaneous T-cell lymphoma (CTCL). Under the terms of the interim analysis, the study was recommended to halt for futility. "We are obviously very disappointed with the unanticipated outcome of the study," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "Despite the fact that HyBryte™ demonstrated statistically significant reductions in CTCL lesions after 6 weeks treatment in the first FLASH study, a similar signal was not observed with 18 weeks of treatment in this study. Over the coming weeks, we will analyze the data to better determine why the study did not meet expectations. If there is any clarity gained from further analysis of the dataset, especially with respect to specific subsets of patients that may benefit from HyBryte™ therapy, then we intend to communicate our findings and explore follow-up discussions with the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA)." Dr. Schaber continued, "With approximately $5.9 million of cash, we will evaluate all strategic options moving forward, including but not limited to merger and acquisition opportunities as well as the potential of advancing dusquetide for the treatment of Behçet's Disease, which demonstrated promising biological efficacy in a Phase 2 study last year using the intravenous formulation and has received orphan drug designation most recently from the EMA." About HyBryte™ HyBryte™ (research name SGX301) is a novel, first-in-class, photodynamic therapy utilizing safe, visible light for activation. The active ingredient in HyBryte™ is synthetic hypericin, a potent photosensitizer that is topically applied to skin lesions that is taken up by the malignant T-cells, and then activated by safe, visible light approximately 24 hours later. The use of visible light in the red-yellow spectrum has the advantage of penetrating more deeply into the skin (much more so than ultraviolet light) and therefore potentially treating deeper skin disease and thicker plaques and lesions. This treatment approach avoids the risk of secondary malignancies (including melanoma) inherent with the frequently employed DNA-damaging drugs and other phototherapy that are dependent on ultraviolet exposure. Combined with photoactivation, hypericin has demonstrated significant anti-proliferative effects on activated normal human lymphoid cells and inhibited growth of malignant T-cells isolated from CTCL patients. In a published Phase 2 clinical study in CTCL, patients experienced a statistically significant (p=0.04) improvement with topical hypericin treatment whereas the placebo was ineffective. HyBryte™ has received orphan drug and fast track designations from the FDA, as well as orphan designation from the European Medicines Agency (EMA). The published Phase 3 FLASH trial enrolled a total of 169 patients (166 evaluable) with Stage IA, IB or IIA CTCL. The trial consisted of three treatment cycles. Treatments were administered twice weekly for the first 6 weeks and treatment response was determined at the end of the 8th week of each cycle. In the first double-blind treatment cycle (Cycle 1), 116 patients received HyBryte™ treatment (0.25% synthetic hypericin) and 50 received placebo treatment of their index lesions. A total of 16% of the patients receiving HyBryte™ achieved at least a 50% reduction in their lesions (graded using a standard measurement of dermatologic lesions, the modified Composite Assessment of Index Lesion Severity [mCAILS] score) compared to only 4% of patients in the placebo group at 8 weeks (p=0.04) during the first treatment cycle (primary endpoint). HyBryte™ treatment in this cycle was safe and well tolerated. In the second open-label treatment cycle (Cycle 2), all patients received HyBryte™ treatment of their index lesions. Evaluation of 155 patients in this cycle (110 receiving 12 weeks of HyBryte™ treatment and 45 receiving 6 weeks of placebo treatment followed by 6 weeks of HyBryte™ treatment), demonstrated that the response rate among the 12-week treatment group was 40% (p<0.0001 vs the placebo treatment rate in Cycle 1). Comparison of the 12-week and 6-week treatment responses also revealed a statistically significant improvement (p<0.0001) between the two timepoints, indicating that continued treatment results in better outcomes. HyBryte™ continued to be safe and well tolerated. Additional analyses also indicated that HyBryte™ is equally effective in treating both plaque (response 42%, p<0.0001 relative to placebo treatment in Cycle 1) and patch (response 37%, p=0.0009 relative to placebo treatment in Cycle 1) lesions of CTCL, a particularly relevant finding given the historical difficulty in treating plaque lesions. The third (optional) treatment cycle (Cycle 3) was focused on safety and all patients could elect to receive HyBryte™ treatment of all their lesions. Of note, 66% of patients elected to continue with this optional compassionate use / safety cycle of the study. Of the subset of patients that received HyBryte™ throughout all 3 cycles of treatment, 49% of them demonstrated a positive treatment response (p<0.0001 vs patients receiving placebo in Cycle 1). Moreover, in a subset of patients evaluated in this cycle, it was demonstrated that HyBryte™ is not systemically available, consistent with the general safety of this topical product observed to date. At the end of Cycle 3, HyBryte™ continued to be well tolerated despite extended and increased use of the product to treat multiple lesions. Overall safety of HyBryte™ is a critical attribute of this treatment and was monitored throughout the three treatment cycles (Cycles 1, 2 and 3) and the 6-month follow-up period. HyBryte's™ mechanism of action is not associated with DNA damage, making it a safer alternative than currently available therapies, all of which are associated with significant, and sometimes fatal, side effects. Predominantly these include the risk of melanoma and other malignancies, as well as the risk of significant skin damage and premature skin aging. Currently available treatments are only approved in the context of previous treatment failure with other modalities and there is no approved front-line therapy available. Within this landscape, treatment of CTCL is strongly motivated by the safety risk of each product. HyBryte™ potentially represents the safest available efficacious treatment for CTCL. With very limited systemic absorption, a compound that is not mutagenic and a light source that is not carcinogenic, there is no evidence to date of any potential safety issues. Following the first Phase 3 study of HyBryte™ for the treatment of CTCL, the FDA and the EMA indicated that they would require a second successful Phase 3 trial to support marketing approval. With agreement from the EMA on the key design components, the second, confirmatory study, called FLASH2, has demonstrated a good safety profile in the pre-specific safety evaluations by the Data Monitoring Committee. This study is a randomized, double-blind, placebo-controlled, multicenter study that replicates the double-blind, placebo-controlled design used in the first successful Phase 3 FLASH study that consisted of three 6-week treatment cycles (18 weeks total), with the primary efficacy assessment occurring at the end of the initial 6-week double-blind, placebo-controlled treatment cycle (Cycle 1). However, this second study extends the double-blind, placebo-controlled assessment to 18 weeks of continuous treatment (no "between-Cycle" treatment breaks) with the primary endpoint assessment occurring at the end of the 18-week timepoint. In the first Phase 3 study, a treatment response of 49% (p<0.0001 vs patients receiving placebo in Cycle 1) was observed in patients completing 18 weeks (3 cycles) of therapy. In this second study, all important clinical study design components remain the same as in the first FLASH study, including the primary endpoint and key inclusion-exclusion criteria. In light of the interim analysis results, the Company will evaluate all available data and assess potential next steps, if any, with respect to the HyBryte™ development program. Additional supportive studies have demonstrated the utility of longer treatment times (Study RW-HPN-MF-01), the lack of significant systemic exposure to hypericin after topical application (Study HPN-CTCL-02) and its relative efficacy and tolerability compared to Valchlor® (Study HPN-CTCL-04). In addition, the FDA awarded an Orphan Products Development grant to support the investigator-initiated study evaluation of HyBryte™ for expanded treatment in patients with early-stage CTCL, including in the home use setting. The grant, totaling $2.6 million over 4 years, was awarded to the University of Pennsylvania that was a leading enroller in the Phase 3 FLASH study. About Cutaneous T-Cell Lymphoma (CTCL) CTCL is a class of non-Hodgkin's lymphoma (NHL), a type of cancer of the white blood cells that are an integral part of the immune system. Unlike most NHLs which generally involve B-cell lymphocytes (involved in producing antibodies), CTCL is caused by an expansion of malignant T-cell lymphocytes (involved in cell-mediated immunity) normally programmed to migrate to the skin. These malignant cells migrate to the skin where they form various lesions, typically beginning as patches and may progress to raised plaques and tumors. Mortality is related to the stage of CTCL, with median survival generally ranging from about 12 years in the early stages to only 2.5 years when the disease has advanced. There is currently no cure for CTCL. Typically, CTCL lesions are treated and regress but usually return either in the same part of the body or in new areas. CTCL constitutes a rare group of NHLs, occurring in about 4% of the more than 1.7 million individuals living with the disease in the U.S. and Europe (European Union and United Kingdom). It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of CTCL that it affects approximately 31,000 individuals in the U.S. (based on SEER [Surveillance, Epidemiology, and End Results] data, with approximately 3,200 new cases seen annually) and approximately 38,000 individuals in Europe (based on ECIS [European Cancer Information System] prevalence estimates, with approximately 3,800 new cases annually). 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 HyBryte™ (SGX301 or synthetic hypericin sodium) as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma (CTCL). 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 X at @Soligenix_Inc. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements, and include the expected timing and results of clinical trials and the expected timing of regulatory submissions and approvals. In light of the discontinuation of the FLASH2 study, the Company's ability to continue as a going concern will be dependent upon its ability to develop and commercialize its remaining pipeline assets, including dusquetide for the treatment of Behçet's Disease, to identify and acquire or in-license additional product candidates or technologies, and to raise sufficient capital to fund such development and any such acquisitions. There can be no assurance that the Company will be able to obtain financing on acceptable terms, if at all, that suitable acquisition or in-licensing opportunities will be available, or that any of its remaining or future development programs will be successful. If the Company is unable to raise sufficient capital or otherwise advance its remaining assets, it may be required to significantly curtail or cease its operations, sell or otherwise dispose of its assets, or pursue dissolution and liquidation. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded study response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, notwithstanding any prior observations regarding such blinded response rate, the second HyBryte™ (SGX301) Phase 3 clinical trial did not demonstrate sufficient efficacy at the interim analysis to support continuation of the study, and no assurance can be given that any further development of HyBryte™ (SGX301) will be pursued or that a marketing authorization from the FDA or EMA will be sought or granted. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/soligenix-announces-interim-results-from-the-phase-3-flash2-trial-evaluating-hybryte-in-treatment-of-cutaneous-t-cell-lymphoma-302754503.html

LOS ANGELES, CA - April 17, 2026 (NEWMEDIAWIRE) - Advancing clinical research while generating positive data is a critical combination in biotechnology, particularly when addressing diseases with limited treatment options. Soligenix (NASDAQ: SNGX) is demonstrating that momentum as it provides both an encouraging clinical update from its phase 3 FLASH2 study and positive comparative clinical results for its HyBryte therapy, reinforcing the company's focus on developing innovative treatments for serious conditions. Soligenix reports clinical update centered on cutaneous T-cell lymphoma ("CTCL"), a rare form of non-Hodgkin lymphoma that primarily affects the skin. The interim update highlighted that the overall blinded aggregate response rate observed in patients who have completed treatment remains consistent with prior reporting. In addition, the company reported positive results from a study evaluating HyBryte(TM) against Valchlor(R), an existing treatment option for cutaneous T-cell lymphoma. The research highlighted in these announcements centers on cutaneous T-cell lymphoma ("CTCL"), a rare form of non-Hodgkin lymphoma that primarily affects the skin. According to the National Cancer Institute, CTCL can cause persistent skin lesions, plaques and tumors, often leading to significant Read More Please see full terms of use and disclaimers on the InvestorBrandNetwork website applicable to all content provided by IBN, wherever published or re-published: http://IBN.fm/Disclaimer The latest news and updates relating to SNGX are available in the company's newsroom at https://ibn.fm/SNGX Forward Looking Statements Certain statements in this article are forward-looking, as defined in the Private Securities Litigation Reform Act of 1995. These statements involve risks, uncertainties, and other factors that may cause actual results to differ materially from the information expressed or implied by these forward-looking statements and may not be indicative of future results. These forward-looking statements are subject to a number of risks and uncertainties, including, among others, various factors beyond management's control, including the risks set forth under the heading "Risk Factors" discussed under the caption "Item 1A. Risk Factors" in Part I of the Company's most recent Annual Report on Form 10-K or any updates discussed under the caption "Item 1A. Risk Factors" in Part II of the Company's Quarterly Reports on Form 10-Q and in the Company's other filings with the SEC. Undue reliance should not be placed on the forward-looking statements in this article in making an investment decision, which are based on information available to us on the date hereof. All parties undertake no duty to update this information unless required by law View the original release on www.newmediawire.com

LOS ANGELES, CA - April 2, 2026 (NEWMEDIAWIRE) - Soligenix (NASDAQ: SNGX) announced the publication of positive results from its comparability study evaluating HyBryte(TM) versus Valchlor(R) for the treatment of cutaneous T-cell lymphoma in Oncology and Therapy, highlighting favorable efficacy and safety outcomes. After 12 weeks, 60% of HyBryte-treated patients achieved treatment success compared to 20% for Valchlor, with greater average improvement and no treatment-related adverse events reported for HyBryte, while Valchlor patients experienced multiple adverse reactions, supporting HyBryte's potential as a well-tolerated therapy for early-stage CTCL. To view the full press release, visit https://ibn.fm/Eq1BX About Soligenix 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(TM) (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 Behcet's Disease. Our Public Health Solutions business segment includes development programs for RiVax(R), our ricin toxin vaccine candidate, as well as our vaccine programs targeting filoviruses (such as Marburg and Ebola) and CiVax(TM), 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(R). 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). Please see full terms of use and disclaimers on the InvestorBrandNetwork website applicable to all content provided by IBN, wherever published or re-published: http://IBN.fm/Disclaimer The latest news and updates relating to SNGX are available in the company's newsroom at https://ibn.fm/SNGX Forward Looking Statements Certain statements in this article are forward-looking, as defined in the Private Securities Litigation Reform Act of 1995. These statements involve risks, uncertainties, and other factors that may cause actual results to differ materially from the information expressed or implied by these forward-looking statements and may not be indicative of future results. These forward-looking statements are subject to a number of risks and uncertainties, including, among others, various factors beyond management's control, including the risks set forth under the heading "Risk Factors" discussed under the caption "Item 1A. Risk Factors" in Part I of the Company's most recent Annual Report on Form 10-K or any updates discussed under the caption "Item 1A. Risk Factors" in Part II of the Company's Quarterly Reports on Form 10-Q and in the Company's other filings with the SEC. Undue reliance should not be placed on the forward-looking statements in this article in making an investment decision, which are based on information available to us on the date hereof. All parties undertake no duty to update this information unless required by law

LOS ANGELES, CA - April 1, 2026 (NEWMEDIAWIRE) - Soligenix (NASDAQ: SNGX) reported 2025 results highlighting progress across its rare disease pipeline, including advancing its Phase 3 FLASH2 trial of HyBryte(TM) for cutaneous T-cell lymphoma with interim analysis expected in Q2 2026 and top-line results anticipated in the second half of the year. The company also noted regulatory momentum with orphan drug designation for dusquetide in Behcet's Disease, ongoing development of SGX302 and SGX945 programs and a year-end cash position of approximately $7.9 million, as it continues to pursue strategic options to support late-stage development. To view the full press release, visit https://ibn.fm/b1p2y About Soligenix 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(TM) (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 Behcet's Disease. Our Public Health Solutions business segment includes development programs for RiVax(R), our ricin toxin vaccine candidate, as well as our vaccine programs targeting filoviruses (such as Marburg and Ebola) and CiVax(TM), 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(R). 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). Please see full terms of use and disclaimers on the InvestorBrandNetwork website applicable to all content provided by IBN, wherever published or re-published: http://IBN.fm/Disclaimer The latest news and updates relating to SNGX are available in the company's newsroom at https://ibn.fm/SNGX Forward Looking Statements Certain statements in this article are forward-looking, as defined in the Private Securities Litigation Reform Act of 1995. These statements involve risks, uncertainties, and other factors that may cause actual results to differ materially from the information expressed or implied by these forward-looking statements and may not be indicative of future results. These forward-looking statements are subject to a number of risks and uncertainties, including, among others, various factors beyond management's control, including the risks set forth under the heading "Risk Factors" discussed under the caption "Item 1A. Risk Factors" in Part I of the Company's most recent Annual Report on Form 10-K or any updates discussed under the caption "Item 1A. Risk Factors" in Part II of the Company's Quarterly Reports on Form 10-Q and in the Company's other filings with the SEC. Undue reliance should not be placed on the forward-looking statements in this article in making an investment decision, which are based on information available to us on the date hereof. All parties undertake no duty to update this information unless required by law

HyBryte™ demonstrates more rapid and robust treatment response compared to Valchlor® during 12-week treatment course PRINCETON, N.J., April 2, 2026 /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 that the positive results of its comparability study evaluating HyBryte™ (synthetic hypericin) versus Valchlor® (mechlorethamine) for the treatment of cutaneous T-cell lymphoma (CTCL) have been published in Oncology and Therapy. "Being able to share the important results of this clinical trial with the world through publication in Oncology and Therapy is a privilege and highlights the clinical significance of our work with HyBryte™," stated Brian Poligone, MD, PhD, Director of the Rochester Skin Lymphoma Medical Group, Fairport, NY, and Principal Investigator for the comparability study. "Despite the small study sample size and a randomization that lead to the HyBryte™ group having patients with more extensive disease, HyBryte™ performed well and the results are consistent with previous studies demonstrating its rapid onset of action and benign safety profile compared to one of the most widely prescribed approved drugs for early-stage CTCL. The positive effect this therapy can have for patients and the outstanding safety profile that HyBryte™ continues to demonstrate are very encouraging." The purpose of the study was to obtain preliminary comparative assessment of the safety and efficacy of HyBryte™ versus Valchlor® following 12 weeks of treatment as measured in 3 to 5 prospectively identified index lesions for each patient. At the end of the 12-week treatment period, 60% of the HyBryte™ patients met the prospectively defined level of "Treatment Success" (≥50% improvement in their cumulative mCAILS score compared to Baseline) compared to only 20% of the Valchlor® patients; although due to the small sample size the results do not achieve statistical significance. Of the remaining two HyBryte™ patients that did not achieve treatment success, both saw a substantial (≥30%) reduction in their mCAILS score. In contrast, in the Valchlor® group, of the remaining 4 patients that did not achieve treatment success, one worsened and dropped from the study, one improved less than 30% and two improved greater than 30%. The average cumulative improvement in mCAILS at 12 weeks was 52.5% in the HyBryte™ patients versus 34.7% in the Valchlor® patients. HyBryte™ was well tolerated in all patients whereas 1 of the 5 patients receiving Valchlor® had to be withdrawn from the trial because of a clinically significant allergic contact dermatitis from Valchlor®. When comparing the tolerance of the topical therapies (i.e., reactions where the drug was applied to the skin) in this trial, it is notable that all patients tolerated HyBryte™ well and had no adverse events "related" to the therapy. In contrast, 60% of the Valchlor® treated patients had at least one adverse event "related" to the therapy. These adverse events in the Valchlor® group included rashes, application site sensitivity, allergic contact dermatitis, and dermatitis, with one patient requiring steroid treatment, one requiring temporary interruption of Valchlor® treatment, and one requiring permanent discontinuation of Valchlor®. No such instances were reported in the HyBryte™ group. About Oncology and Therapy Oncology and Therapy is an international, open access, peer-reviewed, and rapid publication journal. The scope of the journal is broad, dedicated to the publication of high-quality clinical, observational, real-world, patient care, and health outcomes research around the discovery, development, and use of therapeutics and interventions across all areas of oncology. The key features of the journal are rapid publication, open access, inclusivity, personal service, digital features, plain language summaries and novel article types. About HyBryte™ HyBryte™ (research name SGX301) is a novel, first-in-class, photodynamic therapy utilizing safe, visible light for activation. The active ingredient in HyBryte™ is synthetic hypericin, a potent photosensitizer that is topically applied to skin lesions that is taken up by the malignant T-cells, and then activated by safe, visible light approximately 24 hours later. The use of visible light in the red-yellow spectrum has the advantage of penetrating more deeply into the skin (much more so than ultraviolet light) and therefore potentially treating deeper skin disease and thicker plaques and lesions. This treatment approach avoids the risk of secondary malignancies (including melanoma) inherent with the frequently employed DNA-damaging drugs and other phototherapy that are dependent on ultraviolet exposure. Combined with photoactivation, hypericin has demonstrated significant anti-proliferative effects on activated normal human lymphoid cells and inhibited growth of malignant T-cells isolated from CTCL patients. In a published Phase 2 clinical study in CTCL, patients experienced a statistically significant (p=0.04) improvement with topical hypericin treatment whereas the placebo was ineffective. HyBryte™ has received orphan drug and fast track designations from the FDA, as well as orphan designation from the European Medicines Agency (EMA). The published Phase 3 FLASH trial enrolled a total of 169 patients (166 evaluable) with Stage IA, IB or IIA CTCL. The trial consisted of three treatment cycles. Treatments were administered twice weekly for the first 6 weeks and treatment response was determined at the end of the 8th week of each cycle. In the first double-blind treatment cycle (Cycle 1), 116 patients received HyBryte™ treatment (0.25% synthetic hypericin) and 50 received placebo treatment of their index lesions. A total of 16% of the patients receiving HyBryte™ achieved at least a 50% reduction in their lesions (graded using a standard measurement of dermatologic lesions, the modified Composite Assessment of Index Lesion Severity [mCAILS] score) compared to only 4% of patients in the placebo group at 8 weeks (p=0.04) during the first treatment cycle (primary endpoint). HyBryte™ treatment in this cycle was safe and well tolerated. In the second open-label treatment cycle (Cycle 2), all patients received HyBryte™ treatment of their index lesions. Evaluation of 155 patients in this cycle (110 receiving 12 weeks of HyBryte™ treatment and 45 receiving 6 weeks of placebo treatment followed by 6 weeks of HyBryte™ treatment), demonstrated that the response rate among the 12-week treatment group was 40% (p<0.0001 vs the placebo treatment rate in Cycle 1). Comparison of the 12-week and 6-week treatment responses also revealed a statistically significant improvement (p<0.0001) between the two timepoints, indicating that continued treatment results in better outcomes. HyBryte™ continued to be safe and well tolerated. Additional analyses also indicated that HyBryte™ is equally effective in treating both plaque (response 42%, p<0.0001 relative to placebo treatment in Cycle 1) and patch (response 37%, p=0.0009 relative to placebo treatment in Cycle 1) lesions of CTCL, a particularly relevant finding given the historical difficulty in treating plaque lesions. The third (optional) treatment cycle (Cycle 3) was focused on safety and all patients could elect to receive HyBryte™ treatment of all their lesions. Of note, 66% of patients elected to continue with this optional compassionate use / safety cycle of the study. Of the subset of patients that received HyBryte™ throughout all 3 cycles of treatment, 49% of them demonstrated a positive treatment response (p<0.0001 vs patients receiving placebo in Cycle 1). Moreover, in a subset of patients evaluated in this cycle, it was demonstrated that HyBryte™ is not systemically available, consistent with the general safety of this topical product observed to date. At the end of Cycle 3, HyBryte™ continued to be well tolerated despite extended and increased use of the product to treat multiple lesions. Overall safety of HyBryte™ is a critical attribute of this treatment and was monitored throughout the three treatment cycles (Cycles 1, 2 and 3) and the 6-month follow-up period. HyBryte's™ mechanism of action is not associated with DNA damage, making it a safer alternative than currently available therapies, all of which are associated with significant, and sometimes fatal, side effects. Predominantly these include the risk of melanoma and other malignancies, as well as the risk of significant skin damage and premature skin aging. Currently available treatments are only approved in the context of previous treatment failure with other modalities and there is no approved front-line therapy available. Within this landscape, treatment of CTCL is strongly motivated by the safety risk of each product. HyBryte™ potentially represents the safest available efficacious treatment for CTCL. With very limited systemic absorption, a compound that is not mutagenic and a light source that is not carcinogenic, there is no evidence to date of any potential safety issues. Following the first Phase 3 study of HyBryte™ for the treatment of CTCL, the FDA and the EMA indicated that they would require a second successful Phase 3 trial to support marketing approval. With agreement from the EMA on the key design components, the second, confirmatory study, called FLASH2, has successfully achieved its first safety review milestone with a pre-specified, blinded interim analysis expected to be completed in 2Q2026. This study is a randomized, double-blind, placebo-controlled, multicenter study that will enroll approximately 80 subjects with early-stage CTCL. The FLASH2 study replicates the double-blind, placebo-controlled design used in the first successful Phase 3 FLASH study that consisted of three 6-week treatment cycles (18 weeks total), with the primary efficacy assessment occurring at the end of the initial 6-week double-blind, placebo-controlled treatment cycle (Cycle 1). However, this second study extends the double-blind, placebo-controlled assessment to 18 weeks of continuous treatment (no "between-Cycle" treatment breaks) with the primary endpoint assessment occurring at the end of the 18-week timepoint. In the first Phase 3 study, a treatment response of 49% (p<0.0001 vs patients receiving placebo in Cycle 1) was observed in patients completing 18 weeks (3 cycles) of therapy. In this second study, all important clinical study design components remain the same as in the first FLASH study, including the primary endpoint and key inclusion-exclusion criteria. The extended treatment for a continuous 18 weeks in a single cycle is expected to statistically demonstrate HyBryte's™ increased effect over a more prolonged, "real world" treatment course. Given the extensive engagement with the CTCL community, the esteemed Medical Advisory Board and the previous trial experience with this disease, accelerated enrollment in support of this study is anticipated, including the potential to enroll previously identified and treated HyBryte™ patients from the FLASH study. Discussions with the FDA on an appropriate study design remain ongoing. While collaborative, the agency has expressed a preference for a longer duration comparative study over a placebo-controlled trial. Given the shorter time to potential commercial revenue and the similar trial design to the first FLASH study afforded by the EMA accepted protocol, this study was initiated. At the same time, discussions with the FDA will continue on potential modifications to the development path to adequately address their feedback. Additional supportive studies have demonstrated the utility of longer treatment times (Study RW-HPN-MF-01), the lack of significant systemic exposure to hypericin after topical application (Study HPN-CTCL-02) and its relative efficacy and tolerability compared to Valchlor® (Study HPN-CTCL-04). In addition, the FDA awarded an Orphan Products Development grant to support the investigator-initiated study evaluation of HyBryte™ for expanded treatment in patients with early-stage CTCL, including in the home use setting. The grant, totaling $2.6 million over 4 years, was awarded to the University of Pennsylvania that was a leading enroller in the Phase 3 FLASH study. About Cutaneous T-Cell Lymphoma (CTCL) CTCL is a class of non-Hodgkin's lymphoma (NHL), a type of cancer of the white blood cells that are an integral part of the immune system. Unlike most NHLs which generally involve B-cell lymphocytes (involved in producing antibodies), CTCL is caused by an expansion of malignant T-cell lymphocytes (involved in cell-mediated immunity) normally programmed to migrate to the skin. These malignant cells migrate to the skin where they form various lesions, typically beginning as patches and may progress to raised plaques and tumors. Mortality is related to the stage of CTCL, with median survival generally ranging from about 12 years in the early stages to only 2.5 years when the disease has advanced. There is currently no cure for CTCL. Typically, CTCL lesions are treated and regress but usually return either in the same part of the body or in new areas. CTCL constitutes a rare group of NHLs, occurring in about 4% of the more than 1.7 million individuals living with the disease in the U.S. and Europe (European Union and United Kingdom). It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of CTCL that it affects approximately 31,000 individuals in the U.S. (based on SEER [Surveillance, Epidemiology, and End Results] data, with approximately 3,200 new cases seen annually) and approximately 38,000 individuals in Europe (based on ECIS [European Cancer Information System] prevalence estimates, with approximately 3,800 new cases annually). 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. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements, and include the expected amount and use of proceeds from the offering and the expected closing date of the offering. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded study response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, there can be no assurance that the second HyBryte™ (SGX301) Phase 3 clinical trial will be successful or that a marketing authorization from the FDA or EMA will be granted. Additionally, although the EMA has agreed to the key design components of the second HyBryte™ (SGX301) Phase 3 clinical trial, no assurance can be given that the Company will be able to modify the development path to adequately address the FDA's concerns or that the FDA will not require a longer duration comparative study. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/positive-clinical-results-from-hybryte-comparative-study-evaluating-hybryte-against-valchlor-in-the-treatment-of-cutaneous-t-cell-lymphoma-published-in-oncology-and-therapy-302732442.html

Upcoming high-impact milestones include interim analysis in Q2 2026 and top-line results in H2 2026 from HyBryte™ trial PRINCETON, N.J., March 31, 2026 /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 its recent accomplishments and financial results for the year ended December 31, 2025. "We are entering a pivotal year with several high-impact clinical and regulatory milestones across our rare disease pipeline," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "Key among these milestones is the interim analysis from the confirmatory Phase 3 FLASH2 (Fluorescent Light And Synthetic Hypericin 2) clinical trial of HyBryte™ (SGX301 or synthetic hypericin) for the treatment of early-stage cutaneous T-cell lymphoma (CTCL) slated for the second quarter and the release of top-line results from this trial expected in the second half of 2026. The overall blinded aggregate response rate in this trial remains consistent with what was previously reported and is higher than the estimated overall response rate used to design the study, increasing our confidence in the interim analysis and final study results. Additionally, we are advancing our inflammatory disease programs, with plans to initiate a placebo-controlled Phase 2 study of SGX945 (dusquetide) for Behçet's Disease once formulation work for home-use administration is complete in the second half of 2026. We recently reported top-line results for the last cohort of four patients in the Phase 2a clinical trial in mild-to-moderate psoriasis with SGX302 (synthetic hypericin), where SGX302 gel therapy demonstrated clincial benefit in improving psoriasis lesions and was well tolerated by all patients with no drug related adverse events identified." Dr. Schaber continued, "Ending 2025 with approximately $7.9 million in cash, we remain focused on disciplined capital management to drive our strategic objectives. While our current cash balance provides operating runway into Q4 2026, we continue to evaluate all strategic options, including partnership, merger and acquisition, government grants, and potential financing opportunities to advance our late-stage pipeline and the Company." Soligenix Recent Accomplishments On March 26, 2026, the Company announced that the European Commission, acting on the positive recommendation from the European Medicines Agency (EMA) Committee for Orphan Medicinal Products (COMP), granted orphan drug designation to dusquetide (the active pharmaceutical ingredient in SGX945) for the treatment of Behçet's Disease. To view this press release, please click here. On March 23, 2026, the Company announced that findings from recent supportive trials with HyBryte™ in the treatment of CTCL are being presented at the United States Cutaneous Lymphoma Consortium Workshop. To view this press release, please click here. On March 19, 2026, the Company announced that a summary of clinical trials completed to date evaluating HyBryte™ as a treatment for CTCL has been published in the peer-reviewed medical journal Expert Opinion on Investigational Drugs. To view the publication, please click here. To view this press release, please click here. On March 10, 2026, the Company announced that SGX945 has been granted Promising Innovative Medicine designation in the United Kingdom by the Medicines and Healthcare Products Regulatory Agency for the treatment of Behçet's Disease. To view this press release, please click here. On February 26, 2026, the Company announced that the EMA COMP provided a positive recommendation on the Company's request for orphan drug designation for dusquetide (the active pharmaceutical ingredient in SGX945) for the treatment of Behçet's Disease, following review of the recently published Phase 2a clinical results demonstrating biological efficacy and safety in patients with Behçet's Disease. To view this press release, please click here. On February 12, 2026, the Company issued an update letter detailing recent progress and upcoming milestones. To view this press release, please click here. On December 18, 2025, the Company announced that the results from its Phase 2a proof of concept study evaluating SGX945 in the treatment of Behçet's Disease have been published in Rheumatology (Oxford), in an article entitled "Results from a Pilot Study of Dusquetide for the Treatment of Aphthous Ulcers Associated with Behçet Syndrome". To view this press release, please click here. On December 17, 2025, the Company announced extended results of its ongoing Phase 2a trial of SGX302 for the treatment of mild-to-moderate psoriasis. To view this press release, please click here. On November 19, 2025, the Company announced it had completed the planned enrollment of 50 patients necessary for the interim analysis in its 80 patient confirmatory Phase 3 double-blind, placebo-controlled study evaluating HyBryte™ in the treatment of CTCL. To view this press release, please click here. Financial Results – Quarter Ended December 31, 2025 Soligenix reported no revenues for the year ended December 31, 2025, compared to $0.1 million for the prior year. The decrease in revenues was primarily a result of the conclusion of the zero-margin grant for the HyBryte™ investigator-initiated study. Soligenix's net loss was $11.1 million, or ($2.14) per share, for the year ended December 31, 2025, compared to $8.3 million, or ($4.98) per share, for the prior year. The increase in net loss is primarily attributed to increases in research and development costs associated with the Phase 2 study in Behçet's Disease, the ongoing second confirmatory Phase 3 CTCL study; a decrease in other income relating to tax credits; and the change in the fair value of debt. Research and development expenses were $7.5 million as compared to $5.2 million for the years ended December 31, 2025 and 2024, respectively. The increase was primarily related to costs associated with the Phase 2 study in Behçet's Disease and the ongoing second confirmatory Phase 3 CTCL study. General and administrative expenses were $4.4 million and $4.2 million for the years ended December 31, 2025 and 2024, respectively. This increase is primarily attributable to increases in various taxes and stock related expenses offset by a decrease in professional fees. As of December 31, 2025, the Company's cash position was approximately $7.9 million. 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. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations, clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded aggregate response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, there can be no assurance that the second HyBryte™ (SGX301) Phase 3 clinical trial will be successful or that a marketing authorization from the FDA or EMA will be granted. Additionally, although the EMA has agreed to the key design components of the second HyBryte™ (SGX301) Phase 3 clinical trial, no assurance can be given that the Company will be able to modify the development path to adequately address the FDA's concerns or that the FDA will not require a longer duration comparative study. Notwithstanding the result in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/soligenix-announces-recent-accomplishments-and-year-end-2025-financial-results-302728683.html

Highlighting Positive Results in Comparison to Valchlor® and in Real-World Use PRINCETON, N.J., March 23, 2026 /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 that findings from recent supportive trials with HyBryte™ (synthetic hypericin) in the treatment of cutaneous T-cell lymphoma (CTCL) are being presented at the United States Cutaneous Lymphoma Consortium (USCLC) Workshop (March 26, 2026), which precedes the American Academy of Dermatology (AAD) Annual Meeting. Ellen Kim, MD, Director, Penn Cutaneous Lymphoma Program, Vice Chair of Clinical Operations, Dermatology Department, and Professor of Dermatology at the Hospital of the University of Pennsylvania, who was the Principal Investigator for the first Phase 3 FLASH (Fluorescent Light Activated Synthetic Hypericin) study as well as the ongoing Phase 3 FLASH2 study, will present at the USCLC. Dr. Kim will detail positive results from the recently completed investigator-initiated study using HyBryte™ as a long-term treatment of CTCL. A poster also will be presented at the conference sharing the positive results of a study evaluating HyBryte™ versus Valchlor® (mechlorethamine) conducted by Brian Poligone, MD, PhD, Director of the Rochester Skin Lymphoma Medical Group and Principal Investigator for the comparability study. The official conference program can be found here. Oral Presentation: Title: Phase 2 Investigator-Initiated Real-World Study Evaluating Topical Hypericin Ointment Photodynamic Therapy for Early-Stage Mycosis Fungoides/CTCL (RW-HPN-MF-01) presented by Dr. Ellen Kim, Director, Penn Cutaneous Lymphoma Program, Vice Chair of Clinical Operations, Dermatology Department, and Professor of Dermatology at the Hospital of the University of Pennsylvania. Poster Presentation: Title: Results from a Pilot Study of HyBryte™ (topical synthetic hypericin) versus Valchlor® (mechlorethamine) in the Treatment of CTCL attended by Dr. Christopher Pullion, Medical Director, Soligenix, Inc. The poster and presentation review the Company's findings in recent supportive studies, which have demonstrated the clinical benefits of longer treatment times (Study RW-HPN-MF-01; investigator-initiated study), as well as HyBryte's™ relative efficacy and tolerability compared to Valchlor® (Study HPN-CTCL-04). About the USCLC Workshop The United States Cutaneous Lymphoma Consortium is a multidisciplinary society of physicians which use collaborative research and education to improve the quality of life and prognosis of patients with cutaneous lymphoma. This workshop is held annually to facilitate collaboration. The meeting website is available here. About the AAD Annual Meeting The American Academy of Dermatology Association Annual Meeting is one of the largest dermatologic scientific meetings globally and is attended by both researchers and dermatologists. The meeting website is available here. About HyBryte™ HyBryte™ (research name SGX301) is a novel, first-in-class, photodynamic therapy utilizing safe, visible light for activation. The active ingredient in HyBryte™ is synthetic hypericin, a potent photosensitizer that is topically applied to skin lesions that is taken up by the malignant T-cells, and then activated by safe, visible light approximately 24 hours later. The use of visible light in the red-yellow spectrum has the advantage of penetrating more deeply into the skin (much more so than ultraviolet light) and therefore potentially treating deeper skin disease and thicker plaques and lesions. This treatment approach avoids the risk of secondary malignancies (including melanoma) inherent with the frequently employed DNA-damaging drugs and other phototherapy that are dependent on ultraviolet exposure. Combined with photoactivation, hypericin has demonstrated significant anti-proliferative effects on activated normal human lymphoid cells and inhibited growth of malignant T-cells isolated from CTCL patients. In a published Phase 2 clinical study in CTCL, patients experienced a statistically significant (p=0.04) improvement with topical hypericin treatment whereas the placebo was ineffective. HyBryte™ has received orphan drug and fast track designations from the FDA, as well as orphan designation from the European Medicines Agency (EMA). The published Phase 3 FLASH trial enrolled a total of 169 patients (166 evaluable) with Stage IA, IB or IIA CTCL. The trial consisted of three treatment cycles. Treatments were administered twice weekly for the first 6 weeks and treatment response was determined at the end of the 8th week of each cycle. In the first double-blind treatment cycle (Cycle 1), 116 patients received HyBryte™ treatment (0.25% synthetic hypericin) and 50 received placebo treatment of their index lesions. A total of 16% of the patients receiving HyBryte™ achieved at least a 50% reduction in their lesions (graded using a standard measurement of dermatologic lesions, the modified Composite Assessment of Index Lesion Severity [mCAILS] score) compared to only 4% of patients in the placebo group at 8 weeks (p=0.04) during the first treatment cycle (primary endpoint). HyBryte™ treatment in this cycle was safe and well tolerated. In the second open-label treatment cycle (Cycle 2), all patients received HyBryte™ treatment of their index lesions. Evaluation of 155 patients in this cycle (110 receiving 12 weeks of HyBryte™ treatment and 45 receiving 6 weeks of placebo treatment followed by 6 weeks of HyBryte™ treatment), demonstrated that the response rate among the 12-week treatment group was 40% (p<0.0001 vs the placebo treatment rate in Cycle 1). Comparison of the 12-week and 6-week treatment responses also revealed a statistically significant improvement (p<0.0001) between the two timepoints, indicating that continued treatment results in better outcomes. HyBryte™ continued to be safe and well tolerated. Additional analyses also indicated that HyBryte™ is equally effective in treating both plaque (response 42%, p<0.0001 relative to placebo treatment in Cycle 1) and patch (response 37%, p=0.0009 relative to placebo treatment in Cycle 1) lesions of CTCL, a particularly relevant finding given the historical difficulty in treating plaque lesions. The third (optional) treatment cycle (Cycle 3) was focused on safety and all patients could elect to receive HyBryte™ treatment of all their lesions. Of note, 66% of patients elected to continue with this optional compassionate use / safety cycle of the study. Of the subset of patients that received HyBryte™ throughout all 3 cycles of treatment, 49% of them demonstrated a positive treatment response (p<0.0001 vs patients receiving placebo in Cycle 1). Moreover, in a subset of patients evaluated in this cycle, it was demonstrated that HyBryte™ is not systemically available, consistent with the general safety of this topical product observed to date. At the end of Cycle 3, HyBryte™ continued to be well tolerated despite extended and increased use of the product to treat multiple lesions. Overall safety of HyBryte™ is a critical attribute of this treatment and was monitored throughout the three treatment cycles (Cycles 1, 2 and 3) and the 6-month follow-up period. HyBryte's™ mechanism of action is not associated with DNA damage, making it a safer alternative than currently available therapies, all of which are associated with significant, and sometimes fatal, side effects. Predominantly these include the risk of melanoma and other malignancies, as well as the risk of significant skin damage and premature skin aging. Currently available treatments are only approved in the context of previous treatment failure with other modalities and there is no approved front-line therapy available. Within this landscape, treatment of CTCL is strongly motivated by the safety risk of each product. HyBryte™ potentially represents the safest available efficacious treatment for CTCL. With very limited systemic absorption, a compound that is not mutagenic and a light source that is not carcinogenic, there is no evidence to date of any potential safety issues. Following the first Phase 3 study of HyBryte™ for the treatment of CTCL, the FDA and the EMA indicated that they would require a second successful Phase 3 trial to support marketing approval. With agreement from the EMA on the key design components, the second, confirmatory study, called FLASH2, has successfully achieved its first safety review milestone with a pre-specified, blinded interim analysis expected to be completed in 2Q2026. This study is a randomized, double-blind, placebo-controlled, multicenter study that will enroll approximately 80 subjects with early-stage CTCL. The FLASH2 study replicates the double-blind, placebo-controlled design used in the first successful Phase 3 FLASH study that consisted of three 6-week treatment cycles (18 weeks total), with the primary efficacy assessment occurring at the end of the initial 6-week double-blind, placebo-controlled treatment cycle (Cycle 1). However, this second study extends the double-blind, placebo-controlled assessment to 18 weeks of continuous treatment (no "between-Cycle" treatment breaks) with the primary endpoint assessment occurring at the end of the 18-week timepoint. In the first Phase 3 study, a treatment response of 49% (p<0.0001 vs patients receiving placebo in Cycle 1) was observed in patients completing 18 weeks (3 cycles) of therapy. In this second study, all important clinical study design components remain the same as in the first FLASH study, including the primary endpoint and key inclusion-exclusion criteria. The extended treatment for a continuous 18 weeks in a single cycle is expected to statistically demonstrate HyBryte's™ increased effect over a more prolonged, "real world" treatment course. Given the extensive engagement with the CTCL community, the esteemed Medical Advisory Board and the previous trial experience with this disease, accelerated enrollment in support of this study is anticipated, including the potential to enroll previously identified and treated HyBryte™ patients from the FLASH study. Discussions with the FDA on an appropriate study design remain ongoing. While collaborative, the agency has expressed a preference for a longer duration comparative study over a placebo-controlled trial. Given the shorter time to potential commercial revenue and the similar trial design to the first FLASH study afforded by the EMA accepted protocol, this study was initiated. At the same time, discussions with the FDA will continue on potential modifications to the development path to adequately address their feedback. Additional supportive studies have demonstrated the utility of longer treatment times (Study RW-HPN-MF-01), the lack of significant systemic exposure to hypericin after topical application (Study HPN-CTCL-02) and its relative efficacy and tolerability compared to Valchlor® (Study HPN-CTCL-04). In addition, the FDA awarded an Orphan Products Development grant to support the investigator-initiated study evaluation of HyBryte™ for expanded treatment in patients with early-stage CTCL, including in the home use setting. The grant, totaling $2.6 million over 4 years, was awarded to the University of Pennsylvania that was a leading enroller in the Phase 3 FLASH study. About Cutaneous T-Cell Lymphoma (CTCL) CTCL is a class of non-Hodgkin's lymphoma (NHL), a type of cancer of the white blood cells that are an integral part of the immune system. Unlike most NHLs which generally involve B-cell lymphocytes (involved in producing antibodies), CTCL is caused by an expansion of malignant T-cell lymphocytes (involved in cell-mediated immunity) normally programmed to migrate to the skin. These malignant cells migrate to the skin where they form various lesions, typically beginning as patches and may progress to raised plaques and tumors. Mortality is related to the stage of CTCL, with median survival generally ranging from about 12 years in the early stages to only 2.5 years when the disease has advanced. There is currently no cure for CTCL. Typically, CTCL lesions are treated and regress but usually return either in the same part of the body or in new areas. CTCL constitutes a rare group of NHLs, occurring in about 4% of the more than 1.7 million individuals living with the disease in the U.S. and Europe (European Union and United Kingdom). It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of CTCL that it affects approximately 31,000 individuals in the U.S. (based on SEER [Surveillance, Epidemiology, and End Results] data, with approximately 3,200 new cases seen annually) and approximately 38,000 individuals in Europe (based on ECIS [European Cancer Information System] prevalence estimates, with approximately 3,800 new cases annually). 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. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements, and include the expected amount and use of proceeds from the offering and the expected closing date of the offering. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded study response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, there can be no assurance that the second HyBryte™ (SGX301) Phase 3 clinical trial will be successful or that a marketing authorization from the FDA or EMA will be granted. Additionally, although the EMA has agreed to the key design components of the second HyBryte™ (SGX301) Phase 3 clinical trial, no assurance can be given that the Company will be able to modify the development path to adequately address the FDA's concerns or that the FDA will not require a longer duration comparative study. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/hybryte-treatment-results-to-be-presented-at-us-cutaneous-lymphoma-consortium-annual-workshop-2026-302721423.html

By David Bautz, PhD NASDAQ:SNGX READ THE FULL SNGX RESEARCH REPORT Business Update Positive Results for SGX302 in Cohort 3 of Phase 2a Psoriasis Trial On December 17, 2025, Soligenix, Inc. (NASDAQ:SNGX) announced positive results from Cohort 3 of its ongoing Phase 2a trial of SGX302 (synthetic hypericin) for the treatment of mild-to-moderate psoriasis. Cohort 3 consisted of four patients who were enrolled and treated with an improved topical gel formulation of synthetic hypericin. The gel formulation was designed to improve the patient experience as it is easier to dispense and apply to the skin. The patients were treated for 18 weeks, similar to patients in Cohort 1 and 2. For the three evaluable patients (one patient discontinued for personal reasons), noted improvements were seen in the Investigator Global Assessment (IGA), the Psoriasis Activity and Severity Index (PASI), the simplified psoriasis index, the dermatology life quality index and the Skindex-29 questionnaire. Importantly, one patient achieved a disease status of “Almost Clear” using the IGA and a >50% improvement in PASI score. Looking at the totality of the data generated in the Phase 2a trial thus far, its suggestive that SGX302 improves psoriatic lesions and is well tolerated. The ongoing Phase 2a trial is a randomized, double blind, placebo controlled study this is enrolling patients with mild-to-moderate, stable psoriasis covering 2% to 30% of their body. In Cohort 1, five patients received twice weekly treatment for 18 weeks with 0.25% hypericin ointment followed by light activation approximately 24 hours later. Light doses were increased by up to 1 J/cm2 on subsequent visits until mild erythema was observed. A clear biological signal was observed in the initial five patients based on an improvement in the PASI, but no patient met the definition of treatment success (IGA score of 0 or 1). The second cohort of patients received an accelerated light treatment with increases in the light dose by up to 2 J/cm2 allowing the maximum dose (25 J/cm2) to be reached by approximately week 14. Two of the four evaluable patients in Cohort 2 achieved treatment success at some point during the 18-week treatment period and the average reduction in PASI score was approximately 50%. Hypericin combined with visible light treatment could provide a safer treatment option for psoriasis patients compared to therapies that utilize UVA or UVB exposure. In addition, many systemic psoriasis therapies are immunosuppressive and raise the risk of serious infections. Phase 2a Data for SGX945 Published in Rheumatology (Oxford) On Dec. 18, 2025, Soligenix announced the results of its Phase 2a proof-of-concept clinical trial of SGX945 (dusquetide) in the treatment of Behcet’s disease were published in Rheumatology (Oxford) in an article titled, “Results from a Pilot Study of Dusquetide for the Treatment of Aphthous Ulcers Associated with Behcet Syndrome” (Donini et al., 2025). The Phase 2a study was modeled after the Phase 3 clinical trial of apremilast (Otezla®), which served as the basis for marketing approval of that drug for oral ulcers in BD (Hatemi et al., 2019). A total of eight patients were enrolled in the study and administered SGX945 IV twice a week for four weeks. A four-week follow-up was also conducted following cessation of SGX945 treatment. The primary endpoint was the area under the curve (AUC) of the mean number of ulcers versus time. The results of the trial showed that after 4 weeks of treatment, the SGX945-treated group had a 40% improvement relative to the placebo group from the Phase 3 apremilast study. This compares to a 37% improvement for the apremilast group relative to placebo. The improvement in the SGX945-treated group was sustained through the 4-week follow-up period. A 32% improvement relative to placebo was noted at Week 8, even though treatment had stopped at Week 4. Apremilast-treated patients, who were administered drug continuously through Week 12, showed a 41% improvement at Week 8. Notable reports from the SGX945 study include 7/8 patients reporting a perceived benefit from treatment, including reduced duration of oral ulcers, reduced number of oral ulcers, and reduced oral pain. One of the patients had a skin ulcer that resolved during the 4-week treatment period with SGX945. Importantly, SGX945 was well tolerated with no treatment-related adverse events. Commonly reported adverse events in the apremilast study included diarrhea (41%) and nausea (19%), neither of which were reported for SGX945-treated patients. Since SGX945 is currently administered intravenously, Soligenix is planning to reformulate SGX945 as a subcutaneous injection that can administered by patients at home, similar to GLP-1 therapies. Following the reformulation, we anticipate the company performing a placebo-controlled Phase 2b trial of SGX945 in BD patients. Conclusion We’re encouraged by the data reported by the company for the Phase 2a trial of SGX302 in psoriasis. Hypericin could potentially be a safer treatment option for patients as it avoids the use of UVA or UVB light, which is a known risk factor for skin cancer, and it is not immunosuppressive like other systemic therapies. In addition, the publication of the data from the Phase 2a trial of SGX945 in BD is an important step for the program and we look forward to updates from the company regarding the reformulation and advancement of SGX945. With no changes to our model our valuation remains at $25. SUBSCRIBE TO ZACKS SMALL CAP RESEARCH to receive our articles and reports emailed directly to you each morning. Please visit our website for additional information on Zacks SCR. DISCLOSURE: Zacks SCR has received compensation from the issuer directly, from an investment manager, or from an investor relations consulting firm, engaged by the issuer, for providing research coverage for a period of no less than one year. Research articles, as seen here, are part of the service Zacks SCR provides and Zacks SCR receives payments totaling a maximum fee of up to $50,000 annually for these services provided to or regarding the issuer. Full Disclaimer HERE.

Study results support advancing SGX945 in this difficult-to-treat orphan disease Results suggest potential durability of response for maintenance therapy PRINCETON, N.J., Dec. 18, 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 that the results from its Phase 2a proof of concept study evaluating SGX945 (dusquetide) in the treatment of Behçet's Disease have been published in Rheumatology (Oxford), in an article entitled "Results from a Pilot Study of Dusquetide for the Treatment of Aphthous Ulcers Associated with Behçet Syndrome". The Phase 2a study, evaluating control of oral ulcers in Behçet's Disease, reported beneficial effects for 7 of 8 patients, over the 4 weeks of treatment as well as a potentially enduring effect through the 4 weeks of follow-up. Many Behçet's Disease treatments, including the most recently approved apremilast (Otezla®), do not have an enduring impact, necessitating frequent and continuous administration. Using the Phase 3 study of apremilast as a baseline for comparison, this open-label study indicated that the area under the curve (AUC; a composite measurement of both peak number of oral ulcers and the time to resolution of the oral ulcers), average number of oral ulcers, and improvements in oral pain for SGX945 were similar to outcomes obtained in the apremilast study. Notably, outcomes in weeks 5 through 8 continued to show similar outcomes, even though apremilast treatment was continued through this period whereas SGX945 treatment was stopped at Week 4, per study design. The primary endpoint in the Phase 3 apremilast study was the AUC of the mean number of ulcers versus time. Using this same endpoint after 4 weeks of treatment, the SGX945 treated group had a 40% improvement relative to the placebo group from the Phase 3 apremilast study, whereas apremilast had a 37% improvement relative to placebo. This improvement was sustained throughout the 4-week follow-up after treatment with SGX945, with 32% improvement evaluated at Week 8 despite treatment having stopped at Week 4. In contrast, apremilast, which was continuously administered through Week 12, had a 41% improvement at Week 8. The improvements in oral pain mimicked the results in the AUC measurement. Seven of 8 patients reported perceived benefit with SGX945 treatment, with common outcomes including reduced duration of oral ulcers, reduced number of oral ulcers, and reduced oral pain. One patient began the study with a punctuated skin ulcer and this also resolved during the 4-week treatment with SGX945. Skin ulcers are generally considered very difficult to resolve and usually require protracted treatment. Notably, some patients also explicitly reported experiencing fewer ulcers and less pain during the 4-week follow-up period, as also reflected in the numerical analysis. SGX945 was well-tolerated with no treatment-related adverse events. Common adverse events for apremilast included diarrhea (41% of patients), nausea (19% of patients) and headache (14% of patients), none of which were observed with SGX945. "We are pleased to publish the data from our recent SGX945 Phase 2a trial in aphthous ulcers of Behçet's Disease, enabling the medical community to evaluate this novel mechanism and therapeutic," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "Given the role of the innate immune system, we believe that dusquetide may offer significant relief to patients. With these, now published, results, we intend to embark on a reformulation of SGX945 to enable home-based treatment, using subcutaneous injection as used for example with weight-loss drugs. We are excited to expand dusquetide's development into different innate immune-related inflammatory conditions, such as Behçet's Disease, as a component of our long-term strategy to enhance the value of this unique compound. Behçet's Disease is an area of unmet medical need, with up to 18,000 people in the U.S., 50,000 in Europe, 350,000 people in Turkey and as many as 1 million people worldwide affected by this incurable and chronic disease. We look forward to undertaking reformulation and interacting with the health authorities in designing a follow-on clinical study." About Dusquetide Dusquetide, the active ingredient in SGX945 (Behçet's Disease) and SGX942 (oral mucositis), is an innate defense regulator (IDR), a new class of short, synthetic peptides. It has a novel mechanism of action whereby it modulates the body's reaction to both injury and infection towards an anti-inflammatory, anti-infective, and tissue healing response. IDRs have no direct antibiotic activity but, by modulating the host's innate immune system responses, increase survival after infections caused by a broad range of Gram-negative and Gram-positive bacterial pathogens. Dusquetide also accelerates resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma, and chemo- and/or radiation therapy. Preclinical efficacy and safety have been demonstrated in numerous animal disease models including mucositis, colitis, macrophage activation syndrome as well as bacterial infections. In addition, potential anti-tumor activity has been demonstrated in multiple in vitro and in vivo xenograft studies. Dusquetide has demonstrated safety and tolerability in a Phase 1 clinical study in 84 healthy human volunteers. In Phase 2 and 3 clinical studies with dusquetide in over 350 subjects with oral mucositis due to chemoradiation therapy for head and neck cancer, positive efficacy results were demonstrated, including potential long-term ancillary benefits. Dusquetide has also demonstrated biological efficacy and safety in a Phase 2a pilot study in 8 patients with Behçet's Disease. The Phase 2a study was an open-label study designed to be highly comparable (e.g., study endpoints, inclusion-exclusion criteria) to the published Phase 3 study which was used to support marketing approval of apremilast (Otezla®) for oral ulcers in Behçet's disease. The primary endpoint in the Phase 3 apremilast study was the area under the curve (AUC) of the mean number of ulcers versus time. Using this same endpoint after 4 weeks of treatment, the SGX945 treated group had a 40% improvement relative to the placebo group from the Phase 3 apremilast study, whereas apremilast had a 37% improvement relative to placebo. This improvement was sustained throughout the 4-week follow-up after treatment with SGX945, with 32% improvement evaluated at Week 8 despite treatment having stopped at Week 4. In contrast, apremilast, which was continuously administered through Week 12, had a 41% improvement at Week 8. One patient began the study with a punctuated skin ulcer and this also resolved during the 4-week treatment with SGX945. Skin ulcers are generally considered very difficult to resolve and usually require protracted treatment. Notably, some patients also explicitly reported experiencing fewer ulcers and less pain during the 4-week follow-up period, as also reflected in the numerical analysis. SGX945 was well-tolerated with no treatment-related adverse events. Common adverse events for apremilast included diarrhea (41% of patients), nausea (19% of patients) and headache (14% of patients), none of which were observed with SGX945. Soligenix has a strong intellectual property position in the IDR technology platform, including composition of matter for dusquetide and related analogs. Dusquetide was developed pursuant to discoveries made by Professors B. Brett Finlay, PhD and Robert Hancock, PhD of the University of British Columbia, Canada. Dusquetide has been awarded Fast-Track designation for the treatment of oral lesions of Behçet's Disease and Orphan Drug designation for the treatment of Behçet's Disease by the FDA. About Behçet's Disease Behçet's Disease is commonly known as an inflammatory disorder of the blood vessels (vasculitis). Often first diagnosed in young adults, its effects and severity will wax and wane over time. Major signs and symptoms usually include mouth sores (approximately 95% of patients), skin rashes and lesions (approximately 50% of patients), genital sores (approximately 50% of patients), leg ulcers (approximately 40% of patients) and eye inflammation (approximately 15% of patients). It is a painful disease, directly impacting the patient's quality of life and ability to productively engage in life activities, including work. Behçet's Disease is thought to be an auto-immune disease with both genetic and environmental factors. It is most common along the "Silk Road" in the Middle East and East Asia, including Turkey, Iran, Japan and China. There are approximately 18,000 known cases of Behçet's Disease in the U.S. and over 50,000 in Europe. There are as many as 1,000,000 people worldwide living with Behçet's Disease. There is no cure for Behçet's Disease, rather treatments are prescribed to manage symptoms. Treatments may include both maintenance therapies and those specifically addressing flares (e.g., mouth ulcers, genital ulcers and leg ulcers). Corticosteroids are generally applied topically to sores and as eyedrops and may also be given systemically to reduce inflammation. Although used frequently, they have limited efficacy over the long-term and have significant side effects that become more concerning with more chronic use. Genital ulcers are often associated with significant genital scarring while leg ulcers can result in a post-thrombotic syndrome. Other treatments for Behçet's Disease flares involve suppressing the immune system with drugs (e.g., cyclosporine or cyclophosphamide). These drugs come with a higher risk of infection, liver and kidney problems, low blood counts and high blood pressure. Finally, anti-inflammatory drugs are also used, including anti-TNF medications. The only approved drug in Behçet's Disease is apremilast, which is used as a maintenance therapy to prevent formation of oral ulcers. Unfortunately, apremilast must be used continuously to be effective and is associated with both high cost and side effects including diarrhea, nausea, upper respiratory tract infection and headache. 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. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study) and the overall blinded study response rate observed in the second HyBryte™ (SGX301) Phase 3 clinical trial, there can be no assurance that the second HyBryte™ (SGX301) Phase 3 clinical trial will be successful or that a marketing authorization from the FDA or EMA will be granted. Additionally, although the EMA has agreed to the key design components of the second HyBryte™ (SGX301) Phase 3 clinical trial, no assurance can be given that the Company will be able to modify the development path to adequately address the FDA's concerns or that the FDA will not require a longer duration comparative study. Notwithstanding the result of HyBryte™ (SGX301) in the first Phase 3 clinical trial (or any other studies) for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/positive-clinical-results-from-phase-2-trial-of-sgx945-for-the-treatment-of-behcets-disease-published-in-rheumatology-oxford-302645452.html

Optimized Gel Formulation Demonstrates Clinical Success in Third Cohort of Patients PRINCETON, N.J., Dec. 17, 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 extended results of its ongoing Phase 2a trial of SGX302 (synthetic hypericin) for the treatment of mild-to-moderate psoriasis. In this extension (Cohort 3) of the exploratory phase of the study, an additional four patients were enrolled and treated with an improved topical gel formulation of synthetic hypericin. The Cohort 3 patients were treated for the same 18-week period as Cohorts 1 and 2, but utilized an optimized gel formulation of synthetic hypericin. The gel formulation was specifically designed to improve ease of application to larger areas of the skin. SGX302 gel therapy was well tolerated by all patients with no drug related adverse events identified. On average over the three evaluable patients (one patient discontinued for personal reasons), there were improvements in the Investigator Global Assessment (IGA), the Psoriasis Activity and Severity Index (PASI), the simplified psoriasis index, the dermatology life quality index and the Skindex-29 questionnaire. One patient achieved a disease status of "Almost Clear" using the IGA, which is considered a standard clinical measure for treatment success in psoriasis, with a substantial improvement in their PASI score, exceeding 50%. These outcomes were very similar to or improved relative to those obtained with the previous ointment formulation, as expected given the comparable release characteristics of the two formulations and the enhanced ease of application of the gel. In totality, the initial exploratory phase of the study has confirmed that SGX302 improves psoriasis lesions, consistent with the general success of photodynamic therapies in psoriasis, and is well tolerated, potentially providing a non-carcinogenic, non-mutagenic treatment for the thicker lesions found in psoriasis. "We are pleased with the preliminary findings from our ongoing Phase 2a trial," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "The optimized gel formulation was designed to improve the patient experience, with both easier dispensation and skin application. The expansion of this psoriasis study continues our evaluation of synthetic hypericin into other disease indications, including non-orphan indications, where there remains an unmet medical need. Current estimates show as many as 60-125 million people worldwide living with the condition, with a global treatment market valued at approximately $15 billion in 2020 and projected to reach as much as $40 billion by 2027. The success of HyBryte™ in targeting malignant T-cells during cutaneous T-cell lymphoma (CTCL) clinical trials is a promising indicator of the ability of SGX302 to provide a much-needed approach for the treatment of mild-to-moderate psoriasis, also caused by dysregulated T-cells. We anticipate continuing to pursue SGX302 in psoriasis as we advance the confirmatory Phase 3 trial for HyBryte™ in the treatment of early-stage CTCL where topline results are expected in the second half of 2026." About Synthetic Hypericin Visible light-activated synthetic hypericin is a novel, first-in-class, photodynamic therapy (PDT) that is expected to avoid many of the long-term risks associated with other PDT treatments. Synthetic hypericin is a potent photosensitizer that is topically applied to skin lesions and absorbed by cutaneous T-cells. With subsequent activation by safe, visible light, T-cell apoptosis is induced, addressing the root cause of psoriasis lesions. Other PDTs have shown efficacy in psoriasis with a similar apoptotic mechanism, albeit using ultraviolet (UV) light associated with more severe potential long-term safety concerns. The use of visible light in the red-yellow spectrum has the advantage of deeper penetration into the skin (much more than UV light) potentially treating deeper skin disease and thicker plaques and lesions, similar to what was observed in the positive Phase 3 FLASH (Fluorescent Light Activated Synthetic Hypericin) study in CTCL. Synthetic hypericin or HyBryte™ (tradename used in CTCL) was demonstrated in this study to be equally effective in treating both plaque (42% treatment response rate after 12 weeks treatment, p<0.0001 relative to placebo treatment) and patch (37%, p=0.0009) lesions in this orphan disease caused by malignant T-cells. In a published Phase 1/2 proof of concept clinical study using synthetic hypericin, efficacy was demonstrated in patients with CTCL (58.3% response, p=0.04) as well as psoriasis (80% response, p<0.02). In an ongoing Phase 2a study in mild-to-moderate psoriasis, patients enrolled in the initial portion of the trial (Part A) have completed treatment. In Cohort 1, the initial five patients enrolled received twice weekly treatment for 18 weeks with 0.25% hypericin ointment, followed by light activation approximately 24 hours later. Light doses were increased by up to 1 J/cm2 on subsequent visits until mild erythema was observed in the treated lesions. Light doses for all patients were still being intermittently increased when the scheduled treatments ended, and light doses were generally safe and well tolerated. Evaluation of the initial cohort of five patients demonstrated a clear biological signal, with the majority of patients recording an improvement in the PASI (psoriasis area and severity index) score, providing evidence of biological improvement, but no patient met the definition of treatment success (IGA score of 0 or 1) at the 18-week treatment timepoint. The second cohort of five patients were enrolled once the Cohort 1 patients had completed all treatment visits. Given how well-tolerated light treatments were in the first Cohort, it was determined that the second cohort of patients could safely receive an accelerated light treatment with increases in the light dose by up to 2 J/cm2 at each visit and allowing the maximum light dose (25 J/cm2) to be reached earlier by approximately week 14, allowing more treatments at the maximum light dose to be completed in the 18-week treatment schedule. Two of the four evaluable patients achieved a clinical success score at some point during the 18-week treatment period and all evaluable patients improved, yielding an average reduction of approximately 50% in the PASI score. One patient in Cohort 2 dropped out of the study for personal reasons unrelated to the study. The third cohort of the study enrolled four patients, and one of the three evaluable patients achieved a clinical success score, and all evaluable patients improved in multiple indices, including PASI, simplified psoriasis index, and dermatology Life Quality Index. One patient in Cohort 3 discontinued the study for personal reasons and was considered not evaluable. The third cohort specifically assessed the use of an improved formulation of SGX302, designed as a gel as opposed to the previous ointment format. The gel formulation was designed for ease of application and for use in squeezable tubes, instead of jars. This treatment approach avoids the risk of secondary malignancies (including melanoma) inherent with both the frequently used DNA-damaging drugs and other phototherapies that are dependent on UV A or B exposure. The use of synthetic hypericin coupled with safe, visible light also avoids the risk of serious infections and cancer associated with the systemic immunosuppressive treatments used in psoriasis. About Psoriasis Psoriasis is a chronic, non-communicable, itchy and often painful inflammatory skin condition for which there is no cure. Psoriasis has a significantly detrimental impact on patients' quality of life, and is associated with cardiovascular, arthritic, and metabolic diseases, as well as psychological conditions such as anxiety, depression and suicide. Many factors contribute to development of psoriasis including both genetic and environmental factors (e.g., skin trauma, infections, and medications). The lesions develop because of rapidly proliferating skin cells, driven by autoimmune T-cell mediated inflammation. Of the various types of psoriasis, plaque psoriasis is the most common and is characterized by dry, red raised plaques that are covered by silvery-white scales occurring most commonly on the elbows, knees, scalp, and lower back. Approximately 80% of patients have mild-to-moderate disease. Mild psoriasis is generally characterized by the involvement of less than 3% of the body surface area (BSA), while moderate psoriasis will typically involve 3-10% BSA and severe psoriasis greater than 10% BSA. Between 20% and 30% of individuals with psoriasis will go on to develop chronic, inflammatory arthritis (psoriatic arthritis) that can lead to joint deformations and disability. Studies have also associated psoriasis, and particularly severe psoriasis, with an increased relative risk of lymphoma, particularly CTCL. Although psoriasis can occur at any age, most patients present with the condition before age 35. Treatment of psoriasis is based on its severity at the time of presentation with the goal of controlling symptoms. It varies from topical options including PDT to reduce pain and itching, and potentially reduce the inflammation driving plaque formation, to systemic treatments for more severe disease. Most common systemic treatments and even current topical photo/photodynamic therapy such as UV A and B light, carry a risk of increased skin cancer. Psoriasis is the most common immune-mediated inflammatory skin disease. According to the World Health Organization (WHO) Global Report on Psoriasis 2016, the prevalence of psoriasis is between 1.5% and 5% in most developed countries, with some suggestions of incidence increasing with time. It is estimated, based upon review of historic published studies and reports and an interpolation of data, that psoriasis affects 3% of the U.S. population or more than 7.5 million people. Current estimates have as many as 60-125 million people worldwide living with the condition. The global psoriasis treatment market was valued at approximately $15 billion in 2020 and is projected to reach as much as $40 billion by 2027. 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. This press release may contain forward-looking statements that reflect Soligenix's current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment. Statements that are not historical facts, such as "anticipates," "estimates," "believes," "hopes," "intends," "plans," "expects," "goal," "may," "suggest," "will," "potential," or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements. Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of any of its clinical/preclinical trials. Despite the statistically significant result achieved in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma or any other studies (including the open-label, investigator-initiated study), there can be no assurance that the second HyBryte™ (SGX301) Phase 3 clinical trial will be successful or that a marketing authorization from the FDA or EMA will be granted. Additionally, although the EMA has agreed to the key design components of the second HyBryte™ (SGX301) Phase 3 clinical trial, no assurance can be given that the Company will be able to modify the development path to adequately address the FDA's concerns or that the FDA will not require a longer duration comparative study. Notwithstanding the result in the first HyBryte™ (SGX301) Phase 3 clinical trial for the treatment of cutaneous T-cell lymphoma and the Phase 2a clinical trial of SGX302 for the treatment of psoriasis, there can be no assurance as to the timing or success of the clinical trials of SGX302 for the treatment of psoriasis. Additionally, despite the biologic activity observed in aphthous ulcers induced by chemotherapy and radiation, there can be no assurance as to the timing or success of the clinical trials of SGX945 for the treatment of Behçet's Disease. Further, there can be no assurance that RiVax® will qualify for a biodefense Priority Review Voucher (PRV) or that the prior sales of PRVs will be indicative of any potential sales price for a PRV for RiVax®. Also, no assurance can be provided that the Company will receive or continue to receive non-dilutive government funding from grants and contracts that have been or may be awarded or for which the Company will apply in the future. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission (the "SEC"), including, but not limited to, Soligenix's reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events. View original content to download multimedia:https://www.prnewswire.com/news-releases/soligenix-announces-top-line-results-of-the-phase-2a-study-of-sgx302-synthetic-hypericin-in-patients-with-mild-to-moderate-psoriasis-302644314.html