NASDAQ: SNGX

Development programs in this business segment also include expansion of synthetic hypericin into 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).

Our Public Health Solutions business segment includes development programs for (i) RiVax®, a ricin toxin vaccine candidate, (ii) SGX943, a therapeutic candidate for antibiotic resistant and emerging infectious disease, and (iii) various vaccine programs, including a program targeting filoviruses (such as Marburg virus (“MARV”) and Ebola virus (“EBOV”)) and CiVax™, a 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 Biomedical Advanced Research and Development Authority and the Defense Threat Reduction Agency.

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Our business strategy can be outlined as follows:

●Following agreement from the EMA on the key design components for the second confirmatory Phase 3 placebo-controlled FLASH2 clinical trial of HyBryte™ in CTCL and positive primary endpoint results from the first Phase 3 FLASH study, continue enrollment and execution of the FLASH2 study, while at the same time, continuing discussions with the U.S. Food and Drug Administration (“FDA”) on potential modifications to the development path to adequately address their feedback.

●Expand development of synthetic hypericin under the research name SGX302 into psoriasis with the conduct of a Phase 2a clinical trial, following the positive Phase 3 FLASH study and positive proof-of-concept demonstrated in a small Phase 1/2 pilot study in mild-to-moderate psoriasis patients.

●Expand development of dusquetide under the research name SGX945 into BD by conducting a Phase 2 clinical trial, where previous studies with dusquetide in BD have validated the biologic activity in aphthous ulcers in BD.

●Following feedback from the United Kingdom (“UK”) Medicines and Healthcare products Regulatory Agency (“MHRA”) that a second Phase 3 clinical trial of SGX942 (dusquetide) in the treatment of oral mucositis would be

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required to support a marketing authorization, design a second study and attempt to identify a potential partner(s) to continue this development program.

●Continue development of our heat stabilization platform technology, ThermoVax®, in combination with programs for RiVax® (ricin toxin vaccine), and filovirus vaccines (targeting EBOV, Sudan virus (“SUDV”), and MARV and multivalent combinations), with U.S. government or non-governmental organization funding support.

●Continue to apply for additional government funding for each of our Specialized BioTherapeutics and Public Health Solutions programs through grants, contracts and/or procurements.

●Pursue business development opportunities for pipeline programs, as well as explore all strategic alternatives, including but not limited to merger/acquisition strategies.

●Acquire or in-license new clinical-stage compounds for development, as well as evaluate new indications with existing pipeline compounds for development.

Corporate Information

We were incorporated in Delaware in 1987 under the name Biological Therapeutics, Inc. In 1987, we merged with Biological Therapeutics, Inc., a North Dakota corporation, pursuant to which we changed our name to “Immunotherapeutics, Inc.” We changed our name to “Endorex Corp.” in 1996, to “Endorex Corporation” in 1998, to “DOR BioPharma, Inc.” in 2001, and finally to “Soligenix, Inc.” in 2009. Our principal executive offices are located at 29 Emmons Drive, Suite B-10, Princeton, New Jersey 08540 and our telephone number is (609) 538-8200.

Our Product Candidates in Development

The following tables summarize our product candidates under development:

Specialized BioTherapeutics Product Candidates

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Soligenix Product Candidate

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Therapeutic Indication

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Stage of Development

HyBryte™

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Cutaneous T-Cell Lymphoma

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Phase 2 trial completed; demonstrated significantly higher response rate compared to placebo; Phase 3 trial completed; demonstrated statistical significance in primary endpoint in March 2020 (Cycle 1) and demonstrated continued improvement in treatment response with extended treatment in April 2020 (Cycle 2) and October 2020 (Cycle 3); new drug application (“NDA”) submitted to FDA December 2022; FDA refusal to file (“RTF”) letter received February 2023; second Phase 3 trial based upon EMA-accepted protocol began patient enrollment in December 2024 with interim analysis expected in Q2 2026 and top-line results anticipated in the second half of 2026; discussions continue with FDA on modifying the development path to adequately address FDA’s preference for a longer duration comparative study over a placebo-controlled trial

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SGX302

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Mild-to-Moderate Psoriasis

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Positive proof-of-concept demonstrated in a small Phase 1/2 pilot study; Phase 2a protocol

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Soligenix Product Candidate

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Therapeutic Indication

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Stage of Development

and Investigation New Drug (“IND”) clearance received from the FDA; Phase 2a study remains ongoing having demonstrated biological effect in Cohort 1, clinically meaningful benefit in Cohorts 2 and 3, including expanded benefit with a gel formulation in Cohort 3.

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SGX945

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Aphthous Ulcers in BD

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Phase 2a protocol and IND clearance received from the FDA; Phase 2a study complete having achieved the study objective of demonstrating safety and biological efficacy

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SGX942†

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Oral Mucositis in Head and Neck

Cancer

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Phase 2 trial completed; demonstrated significant response compared to placebo with positive long-term (12 month) safety also reported; Phase 3 clinical trial results announced December 2020: the primary endpoint of median duration of severe oral mucositis (“SOM”) did not achieve the pre-specified criterion for statistical significance (p≤0.05); although biological activity was observed with a 56% reduction in the median duration of SOM from 18 days in the placebo group to 8 days in the SGX942 treatment group; analyzed full dataset from Phase 3 study and designing a second Phase 3 clinical trial; continued development contingent upon identification of partnership

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Public Health Solutions†

Soligenix Product Candidate

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Indication

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Stage of Development

ThermoVax®

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Thermostability of vaccines for Ricin toxin, EBOV, and MARV

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Pre-clinical

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RiVax®

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Vaccine against Ricin Toxin Poisoning

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Phase 1a, 1b, and 1c trials completed, safety and neutralizing antibodies for protection demonstrated

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SGX943

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Therapeutic against Emerging

Infectious Diseases

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Pre-clinical

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Contingent upon continued government contract/grant funding or other funding source.

Specialized BioTherapeutics Overview

Synthetic Hypericin

Synthetic Hypericin is a potent photosensitizer that is topically applied to skin lesions, taken up by cutaneous T-cells and then activated by safe visible light. Hypericin is also found in several species of Hypericum plants, although the active moiety used in HyBryte™ and SGX302 is chemically synthesized by a proprietary manufacturing process and not extracted from plants. Importantly, hypericin is optimally activated with visible light thereby avoiding the negative consequences of ultraviolet (“UV”) light. Other light therapies using UVA or UVB light can result in serious adverse effects including secondary skin cancers.

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Combined with photoactivation, in clinical trials synthetic 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 both settings, it appears that the mode of action is an induction of cell death in a concentration as well as a light dose-dependent fashion. These effects appear to result, in part, from the generation of singlet oxygen during photoactivation of hypericin.

Synthetic hypericin is one of the most efficient known generators of singlet oxygen, the key component for phototherapy. The generation of singlet oxygen induces necrosis and apoptosis in cells. The use of topical synthetic hypericin coupled with directed visible light results in generation of singlet oxygen only at the treated site. We believe that the use of visible light (as opposed to cancer-causing UV light) is a major advance in photodynamic therapy. In a small published Phase 1/2 proof of concept pilot clinical study using synthetic hypericin twice weekly for six weeks, statistically significant efficacy was demonstrated in patients with CTCL (58.3% response, p=0.04) and psoriasis (80% response, p<0.02). Subsequently, a published Phase 3 study in CTCL has further confirmed the biological efficacy of synthetic hypericin (termed HyBryte™ in the context of CTCL). A confirmatory, placebo-controlled Phase 3 study based upon an EMA-accepted protocol is actively enrolling with interim analysis expected in the second quarter of 2026 and top-line results expected in the second half of 2026.

HyBryte™ – for Treating Cutaneous T-Cell Lymphoma

HyBryte™ is a novel, first-in-class, PDT, that utilizes safe visible light for activation. The active ingredient in HyBryte™ is synthetic hypericin, a photosensitizer which is topically applied to skin lesions and then activated by visible fluorescent light 16 to 24 hours later.

Based on the positive and previously published Phase 1/2 results, we initiated our Phase 3 clinical study of HyBryte™ for the treatment of CTCL during December 2015 and completed the trial in 2020. This trial, referred to as the FLASH study, aimed to evaluate the response to HyBryte™ as a skin directed therapy to treat early stage CTCL. We completed the study with approximately 35 CTCL centers across the U.S. participating in this trial. The Phase 3 protocol was a highly powered, double-blind, randomized, placebo-controlled, multicenter trial that enrolled 169 subjects (166 evaluable). The trial consisted of three treatment cycles, each of eight weeks duration. Treatments were administered twice weekly for the first six weeks and treatment response was determined at the end of the eighth week. In the first treatment cycle, approximately 66% of subjects received HyBryte™ and 33% received placebo treatment of their index lesions. In the second cycle, all subjects received HyBryte™ treatment of their index lesions, and in the third cycle, all subjects received HyBryte™ treatment of all of their lesions. The majority of subjects enrolled elected to continue into the third optional, open-label cycle of the study. Subjects were followed for an additional six months after their last evaluation visit. The primary efficacy endpoint was assessed on the percentage of patients in each of the two treatment groups (i.e., HyBryte™ and placebo) achieving a partial or complete response of the treated lesions, defined as a ≥ 50% reduction in the total Composite Assessment of Index Lesion Disease Severity (“CAILS”) score for three index lesions at the Cycle 1 evaluation visit (Week 8) compared to the total CAILS score at baseline. Secondary endpoints for the trial included the duration of responses, the extent of the regression of the tumors, and the safety of the treatment. We continue to work closely with the Cutaneous Lymphoma Foundation, as well as the National Organization for Rare Disorders.

Over the course of 2020, analysis of the Phase 3 FLASH study data was completed. The study enrolled 169 patients (166 evaluable) randomized 2:1 to receive either HyBryte™ (116 patients) or placebo (50 patients) and demonstrated a statistically significant treatment response (p=0.04) in the CAILS primary endpoint assessment at 8 weeks for Cycle 1. A total of 16% of the patients receiving HyBryte™ achieved at least a 50% reduction in their index lesions compared to only 4% of patients in the placebo group at 8 weeks. HyBryte™ treatment in the first cycle was safe and well tolerated.

Analysis of the second open-label treatment cycle (Cycle 2) showed that continued treatment with HyBryte™ twice weekly for an additional 6 weeks (12 weeks total) increased the positive response rate to 40% (p<0.0001 compared to placebo and p<0.0001 compared to 6-weeks treatment). The response rate in patients receiving a total of 12 weeks of treatment increased two and a half-fold. Treatment responses were assessed at Week 8 (after 6 weeks of treatment) and at Week 16 (after 12 weeks of treatment). A positive response was defined as an improvement of at least 50% in the CAILS score for the three index lesions evaluated in both Cycles 1 and 2. The data continued to indicate that HyBryte™ was safe and well tolerated.

The optional third open-label treatment cycle (Cycle 3) focused on safety and all patients could elect to receive HyBryte™ treatment of all their lesions for an additional 6 weeks or up to 18 weeks in total. Of note, 66% of patients elected to continue with this optional safety cycle of the study. Of the subset of patients that received HyBryte™ throughout all three cycles of

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treatment (18 weeks), 49% of them demonstrated a treatment response (p=0.046 vs. patients completing 12 weeks of HyBryte™ treatment in Cycle 2; 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.

In addition, continued analysis of results from the protocol mandated efficacy cycles (Cycles 1 and 2) of the study revealed that 12 weeks of treatment (Cycle 2) with HyBryte™ is equally effective on both patch (response 37%, p=0.0009) and plaque (response 42%, p<0.0001) lesions when compared to Cycle 1 placebo lesion responses, further demonstrating the unique benefits of the more deeply penetrating visible light activation of hypericin.

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 confirmatory Phase 3 trial will be a randomized, double-blind, placebo-controlled, multicenter study treating approximately 80 subjects with early-stage CTCL. It will evaluate the efficacy and safety of HyBryte™ topically applied to CTCL lesions twice weekly for 18 weeks, with each application followed 21 (±3) hours later by the administration of safe, visible light at a wavelength of 500 to 650 nm. All of the patient’s lesions that are readily available for exposure to the visible light source will be treated and three to five index lesions of each patient will be prospectively identified and indexed for the modified composite assessment of index lesions severity (“mCAILS”) evaluation prior to randomization (baseline). The primary efficacy endpoint will be assessed on the percent of patients in each of the two treatment groups (i.e., HyBryte™ and placebo) achieving a Partial or Complete Response (yes/no) of the treated lesions defined as a ≥ 50% reduction in the total mCAILS score for the three to five index lesions following 18 weeks of treatment compared to the total mCAILS score at baseline. Other secondary measures will assess treatment response (including duration), degree of improvement, time to relapse and safety. Following treatment, all patients will be followed every four weeks for a total of 12 weeks (through Week 30). The Data Monitoring Committee will conduct one (1) interim analysis when approximately 60% of the total subjects have completed the primary endpoint evaluation. The primary efficacy endpoint and the key safety endpoints will be analyzed. A sample size recalculation may be performed after examining the assumptions or the trial halted for either futility, safety concerns, or overwhelming efficacy. We, the participating clinical investigators, and any other personnel involved in trial conduct will remain blinded to study treatment until completion of the trial.

HyBryte™ has received Orphan Drug designation as well as Fast Track designation from the FDA. The Orphan Drug Act is intended to assist and encourage companies to develop safe and effective therapies for the treatment of rare diseases and disorders. In addition to providing a seven-year term of market exclusivity for HyBryte™ upon final FDA approval, Orphan Drug designation also positions us to be able to leverage a wide range of financial and regulatory benefits, including government grants for conducting clinical trials, waiver of FDA user fees for the potential submission of a NDA for HyBryte™, and certain tax credits. In addition, Fast Track is a designation that the FDA reserves for a drug intended to treat a serious or life-threatening condition and one that demonstrates the potential to address an unmet medical need for the condition. Fast Track designation is designed to facilitate the development and expedite the review of new drugs. For instance, we were eligible to submit a NDA for HyBryte™ on a rolling basis, permitting the FDA to review sections of the NDA prior to receiving the complete submission. Additionally, NDAs for Fast Track development programs ordinarily will be eligible for priority review. HyBryte™ for the treatment of CTCL also was granted Orphan Drug designation from the EMA Committee for Orphan Medical Products and Promising Innovative Medicine (“PIM”) designation from the MHRA, as well as Innovation Passport under the Innovative Licensing and Access Pathway (“ILAP”) in the UK.

In May 2021, HyBryte™ was awarded an "Innovation Passport" for the treatment of early stage CTCL in adults under the UK’s ILAP. The decision to award the Innovation Passport to the HyBryte™ program was made by the Innovative Licensing and Access Pathway Steering Group, which is comprised of representatives from MHRA, the National Institute for Health and Care Excellence (“NICE”), and the Scottish Medicines Consortium (“SMC”). ILAP was launched at the start of 2021 to accelerate the development and access to promising medicines, thereby facilitating patient access to new medicines. The pathway, part of the UK’s plan to attract life sciences development in the post-Brexit era, features enhanced input and interactions with the MHRA, NICE, and SMC. The innovation passport designation is the first step in the ILAP process and triggers the MHRA and its partner agencies to create a target development profile to chart out a roadmap for regulatory and development milestones with the goal of early patient access in the UK. Other benefits of ILAP include a 150-day accelerated assessment, rolling review and a continuous benefit risk assessment.

In June 2021, we received a Paediatric Investigation Plan (“PIP”) waiver from the EMA for HyBryte™. As part of the regulatory process for the registration of new medicines with the EMA, pharmaceutical companies are required to provide

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a PIP outlining their strategies for investigation of the new medicinal products in the pediatric population. In some instances, a waiver negating the need for a PIP for certain conditions may be granted by the EMA when development of a medicine for use in children is not feasible or appropriate, as is the case for HyBryte™ in CTCL which is extremely rare in children.

In July 2022, the results of our successful Phase 3 FLASH study evaluating HyBryte™ for the treatment of CTCL were published in the Journal of the American Medical Association (JAMA) Dermatology.

In July 2022, we received agreement from the FDA on an initial pediatric study plan (“iPSP”) for HyBryte™ for the treatment of CTCL. The agreed iPSP stipulates that we intend to request a full waiver of pediatric studies upon submission of the NDA. Agreement with FDA on an iPSP is one of the regulatory requirements that must be met prior to submitting a NDA.

In September 2022, the FDA awarded an Orphan Products Development grant to support the evaluation of HyBryte™ for expanded treatment in patients with early-stage CTCL. The grant, totaling $2.6 million over four years, was awarded to a prestigious academic institution that was a leading enroller in the published positive Phase 3 FLASH study in the treatment of early stage CTCL.

In December 2022, we submitted the HyBryte™ NDA for the treatment of CTCL with the FDA.

In February 2023, we received a RTF letter from the FDA for the HyBryte™ NDA. Upon preliminary review, the FDA determined that the NDA was not sufficiently complete to permit substantive review.

In April 2023, the United States Adopted Names (“USAN”) Council approved the use of the nonproprietary name of “hypericin sodium” for the novel active ingredient in both HyBryte™ (research name SGX301) for the treatment of CTCL and SGX302 for the treatment of mild-to-moderate psoriasis.

In April 2023, we had a Type A meeting with the FDA to clarify and respond to the issues identified in the RTF letter received from the FDA and to seek additional guidance concerning information that the FDA would require for a resubmitted NDA to be deemed acceptable to file, in order to advance HyBryte™ towards marketing approval and U.S. commercialization. In order to accept an NDA filing for HyBryte™, the FDA is requiring positive results from a second, Phase 3 pivotal study in addition to the Phase 3, randomized, double-blind, placebo-controlled FLASH study previously conducted in this orphan indication. Based on this feedback, we have decided to collaboratively engage in discussions with the FDA in order to define the protocol and evaluate the feasibility of conducting the additional clinical trial.

In May 2023, we were granted a follow-on Type A meeting with the FDA to initiate formal discussions regarding the protocol design of a second, Phase 3 pivotal study evaluating HyBryte™ in the treatment of CTCL in support of potential FDA marketing approval. While discussions have been collaborative, the FDA 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, we determined to initiate the FLASH2 study in support of worldwide potential approval. At the same time, we will continue discussions with the FDA on modifying the development path to adequately address their feedback.

In August 2023, patient enrollment was opened for the investigator-initiated study (“IIS”). The IIS is supported by an Orphan Products Development grant of $2.6 million over four years awarded by the FDA to a prestigious academic institution that was a leading enroller in the published positive Phase 3 FLASH study in the treatment of early-stage CTCL. The IIS will evaluate the expanded treatment, including up to 12 months of treatment, with HyBryte™ in patients with early-stage CTCL.

In March 2024, we received agreement from the EMA on the key design components of a confirmatory Phase 3 placebo-controlled study evaluating the safety and efficacy of HyBryte™ in the treatment of CTCL patients with early-stage disease. This confirmatory 18-week study is expected to enroll approximately 80 patients.

In September 2024, the European Patent Office granted the patent entitled "Systems and Methods for Producing Synthetic Hypericin". The newly issued patent's claims are directed to a novel, highly purified form of synthetic hypericin manufactured through a unique proprietary process. Synthetic hypericin is the active pharmaceutical ingredient in HyBryte™, our photodynamic therapy for the treatment of CTCL, for which a confirmatory Phase 3 clinical trial has been initiated. This new European granted patent (EP3423428) is a related patent to US Pat. No. 10,053,413, previously issued in the U.S. Both patents are expected to expire in 2036, and form part of a larger patent family, including previously granted U.S. patents

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covering methods of use (US Pat. No. 7,122,518) and methods of synthesis (US Pat. No. 8,629,302), as well as other granted patents throughout the world.

In October 2024, we established a partnership agreement with Sterling Pharma Solutions Limited (“Sterling”) to optimize and implement a commercially viable, scalable production technology for synthetic hypericin. We are currently working to transfer and optimize the manufacturing processes and analytics to enable GMP manufacturing for clinical trials with the intent of establishing a long-term commercial manufacturing collaboration.

In October 2024, the Hong Kong Patent Office granted the patent entitled "Systems and Methods for Producing Synthetic Hypericin". The newly issued patent's claims are directed to a novel, highly purified form of synthetic hypericin manufactured through a unique proprietary process. Synthetic hypericin is the active pharmaceutical ingredient in HyBryte™, our photodynamic therapy for the treatment of CTCL, for which a confirmatory Phase 3 clinical trial has been initiated. This new granted patent (HK1260757) is a related patent to US Pat. Nos. 10,053,413 and 10,526,268, previously issued in the U.S., and is in the same family as another patent granted in Europe. These patents are expected to expire in 2036, and form part of a larger collection of different patent families, including previously granted foreign patents covering liquid formulations and methods of use (EP Pat. No. 2,571,507) and issued U.S. patents for methods of synthesis (US Pat. No. 8,629,302), as well as other granted patents throughout the world.

In December 2024, we announced positive clinical results from a comparability study evaluating HyBryte™ versus Valchlor® (mechlorethamine gel) in the treatment of early-stage CTCL. The open-label study has demonstrated continued improvement in HyBryte™ treated patients and their individual lesions even after stopping treatment. The study, which enrolled 10 patients randomized 1:1 with 12 weeks of treatment and 4 weeks of follow-up post-treatment, was previously reported to demonstrate a positive difference in the overall per patient treatment response rate (60% in the HyBryte™ group vs. 20% in the Valchlor® group) at the end of treatment. After the 4-week follow-up period (Week 16), the majority (3 of 5) of HyBryte™ patients continued to demonstrate improvement with at least a further 10% improvement (absolute difference) at Week 16 relative to the primary outcome measure at Week 12, including one of the HyBryte™ patients achieving a "complete response". In contrast, of the four patients that completed the Valchlor® arm of the study, none achieved this level of improvement by Week 16. For patients, a treatment response was defined as a ≥50% improvement in their cumulative mCAILS score over 3 to 5 lesions. Treatment response was also assessed on individual lesions. There was a similar continued improvement in the lesion responses over time, with the plaque lesions of particular interest given their increasing association with risk of overall disease progression and long-term mortality. At the 12-week (end of treatment) timepoint, the HyBryte™ treated plaque lesions were statistically significantly improved compared to the Valchlor® treated plaques (63%, [10/16] treatment success with HyBryte™ vs. 17%, [2/12] with Valchlor®, p=0.02). By Week 16, the response rates in lesions treated with HyBryte™ were statistically significant responses for all lesions (72% HyBryte™ vs 28% Valchlor®, p=0.02) and specifically for plaque lesions (75% responding plaque lesions with HyBryte™ treatment vs. 17% with Valchlor®, p=0.006) relative to the Valchlor® group. No safety concerns with HyBryte™ were raised during the follow-up period.

In December 2024, we opened patient enrollment for our confirmatory Phase 3 study evaluating HyBryte™ (synthetic hypericin) in the treatment of CTCL with top-line results anticipated in the second half of 2026.

In April 2025, we announced positive interim results from the ongoing open-label, IIS evaluating extended HyBryte™ treatment for up to 54 weeks in patients with early-stage CTCL. Following 18 weeks of treatment, 75% of patients achieved "Treatment Success," reinforcing HyBryte™ as a potentially safe and fast-acting therapy for this chronic and underserved cancer. To date, nine patients have been enrolled and treated with HyBryte™ over a time period of up to 54 weeks, with all data for the Week 18 timepoint now complete. Consistent with the Phase 3 trials, Treatment Success is predefined as a greater than or equal to 50% improvement in the cumulative mCAILS score compared to Baseline. Of the eight patients who could be evaluated through Week 18, six (75%) had a Treatment Success. The 18-week treatment window is the same window that is being evaluated in the FLASH2 double-blind, placebo-controlled, randomized study that is currently enrolling patients. This rapid response is a distinct advantage of HyBryte™ therapy, with many other therapies used in CTCL taking up to six to 12 months to generate a clinically meaningful treatment response. Of these eight evaluable patients through Week 18, four have gone on to complete the 54-week treatment with an average maximum improvement in mCAILS score of 85%, with three of the eight evaluable patients achieving a complete response over the course of the study. HyBryte™ appears to be safe and well tolerated in all patients. The trial is sponsored by 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 a leading enroller in the Phase 3 FLASH study for the treatment of early-stage CTCL.

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In July 2025, we successfully completed the transfer of the manufacturing process for our synthetic hypericin active ingredient under our partnership agreement with Sterling. The transfer from Europe to the U.S. included the optimization and implementation of a commercially viable, scalable production process for this important active ingredient, which is used in the topical drug product formulations of HyBryte™ and SGX302, being developed for the treatment of CTCL and psoriasis, respectively. Together with Sterling, we have enabled current good manufacturing practices (“cGMP”) requirements for clinical trials with the intent of establishing a long-term commercial manufacturing collaboration.

In October 2025, the first Data Monitoring Committee meeting for our confirmatory Phase 3 study evaluating HyBryte™ in the treatment of CTCL concluded that there were no safety concerns and that HyBryte™ has an acceptable safety profile that remains consistent with the safety data from all prior clinical studies.

In November 2025, we successfully completed the planned enrollment of 50 patients necessary for the planned interim analysis in the second quarter of 2026 for our confirmatory Phase 3 study evaluating HyBryte™ in the treatment of CTCL and updated our enrollment progress to 66 patients in February of 2026.

In March 2026, a summary of all clinical trials completed to date evaluating HyBryte™ as a treatment for CTCL was published in the peer-reviewed medical journal Expert Opinion on Investigational Drugs.

In March 2026, findings from recent supportive trials with HyBryte™ in the treatment of CTCL were presented at the U.S. Cutaneous Lymphoma Consortium Workshop, preceding the American Academy of Dermatology Annual Meeting.

We estimate the potential worldwide market for HyBryte™ is in excess of $250 million for the treatment of CTCL. This potential market information is a forward-looking statement, and investors are urged not to place undue reliance on this statement. While we have determined this potential market size based on assumptions that we believe are reasonable, there are a number of factors that could cause our expectations to change or not be realized.

Cutaneous T-Cell Lymphoma

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. CTCL is caused by an expansion of malignant T-cell lymphocytes (involved in cell-mediated immunity) normally programmed to migrate to the skin causing various lesions to appear that may change shape as the disease progresses, typically beginning as a rash and eventually forming plaques and tumors. Mycosis fungoides (“MF”) is the most common form of CTCL. It generally presents with skin involvement only, manifested as scaly, erythematous patches. Advanced disease with diffuse lymph node and visceral organ involvement is usually associated with a poorer response rate to standard therapies. A relatively uncommon sub-group of CTCL patients present with extensive skin involvement and circulating malignant cerebriform T-cells, referred to as Sézary syndrome. These patients have substantially graver prognoses (expected five-year survival rate of 24%), than those with MF (expected five-year survival rate of 88%).

CTCL mortality is related to stage of disease, 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 FDA-approved drug for front-line treatment of early-stage CTCL. Treatment of early-stage disease generally involves skin-directed therapies. One of the most common unapproved therapies used for early-stage disease is oral 5 or 8-methoxypsoralen (“Psoralen”) given with ultraviolet A (“UVA”) light, referred to as PUVA, which is approved for dermatological conditions such as disabling psoriasis not adequately responsive to other forms of therapy, idiopathic vitiligo and skin manifestations of CTCL in persons who have not been responsive to other forms of treatment. Psoralen is a mutagenic chemical that interferes with DNA causing mutations and other malignancies. Moreover, UVA is a carcinogenic light source that when combined with the Psoralen, results in serious adverse effects including secondary skin cancers; therefore, the FDA requires a Black Box warning for PUVA.

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 data, with approximately 3,200 new cases seen annually) and approximately 38,000 individuals in Europe (based on ECIS prevalence estimates, with approximately 3,800 new cases annually). We estimate, based upon review of historic published studies and reports and an interpolation of data on the incidence of CTCL, that it affects over 20,000 individuals in the U.S., with approximately 2,800 new cases seen annually.

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SGX302 – for Treating Mild-to-Moderate Psoriasis

SGX302 (synthetic hypericin) is a potent photosensitizer that is topically applied to skin lesions and taken up by cutaneous T-cells. With subsequent activation by safe, visible light, T-cell apoptosis is induced, addressing the dysregulated T-cells found in psoriasis lesions. Other PDTs have shown efficacy in psoriasis with a similar apoptotic mechanism, albeit using UV light associated with more severe potential long-term toxicities. 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 study in CTCL. Further, 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 UVA or UVB exposure. The use of SGX302 coupled with safe, visible light also avoids the risk of serious infections and cancer associated with the systemic immunosuppressive treatments used in psoriasis.

In September 2021, following the validation of synthetic hypericin’s biologic activity in the positive Phase 3 FLASH study in CTCL, as well as positive proof-of-concept demonstrated in a small Phase 1/2 pilot study in mild-to-moderate psoriasis patients, we decided to expand this novel therapy into a Phase 2a clinical trial in mild-to-moderate psoriasis.

In June 2022, we received FDA IND clearance for our Phase 2a clinical trial (protocol number HPN-PSR-01) titled, "Phase 2 Study Evaluating SGX302 in the Treatment of Mild-to-Moderate Psoriasis." In December 2022, we initiated patient enrollment for the Phase 2a study (protocol number HPN-PSR-01) evaluating SGX302 in the treatment of mild-to-moderate psoriasis. The Phase 2a clinical trial (protocol number HPN-PSR-01) will target enrollment of up to 42 patients ages 18 years or older with mild to moderate, stable psoriasis covering 2 to 30% of the body. In both Parts A and B, all patients will apply the study drug twice per week and activate the drug with visible light 24 ± 6 hours later using the supplied visible light devices and according to the manufacturer's instructions. Patients will undergo treatments for a total of 18 weeks and, on completion, will be followed for a four-week follow-up period in which patients will not receive other psoriasis treatments. In Part A, five to ten patients will be assigned open-label SGX302 (0.25% hypericin) at the time of enrollment. Once the tolerability and response to SGX302 has been established, Part B of the protocol will commence. In Part B, patients will be randomized to double-blind treatment groups at a ratio 1:1 of active drug to placebo ointment. Active dermatologic assessment of treated lesions for adverse events will be performed immediately before and during light treatments. Patients will be assessed for overall disease status through four weeks of follow-up. Efficacy endpoints will include the extent of lesion clearance and patient reported quality of life indices. Routine safety data also will be collected.

In July 2023, we expanded the Phase 2a trial of SGX302 after demonstration of biological effect in the initial five subjects (Cohort 1). In January 2024, positive preliminary results of clinical success were demonstrated in the Cohort 2 subjects enrolled in the ongoing Phase 2a study. In the four evaluable patients from Cohort 2 (one patient withdrew early in the treatment course for personal reasons unrelated to the study), two reached a disease status of “Almost Clear” represented by an Investigator Global Assessment score of 1, which is considered the standard clinical measure for treatment success in psoriasis. In addition, the Psoriasis Activity and Severity Index score, another well-characterized measure of treatment success, for patients in Cohort 2 had a mean drop of approximately 50% over the 18-week treatment. SGX302 therapy was well tolerated by all patients with no drug related adverse events identified.

In December 2025, we announced extended results of our 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.

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We estimate the potential worldwide market for SGX302 is in excess of $1 billion for the treatment of mild-to-moderate psoriasis. This potential market information is a forward-looking statement, and investors are urged not to place undue reliance on this statement. While we have determined this potential market size based on assumptions that we believe are reasonable, there are a number of factors that could cause our expectations to change or not be realized.

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, 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.

Dusquetide

Dusquetide (research name: SGX94) is an IDR that regulates the innate immune system to simultaneously reduce inflammation, eliminate infection and enhance tissue healing. Dusquetide is based on a new class of short, synthetic peptides known as IDRs. It has a novel mechanism of action in that it modulates the body’s reaction to both injury and infection and is both simultaneously anti-inflammatory and anti-infective. IDRs have no direct antibiotic activity but modulate host responses, increasing survival after infections with a broad range of bacterial Gram-negative and Gram-positive pathogens including both antibiotic sensitive and resistant strains, as well as accelerating resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma and chemo- or radiation-therapy. IDRs represent a novel approach to the control of infection and tissue damage via highly selective binding to an intracellular adaptor protein, sequestosome-1, also known as p62, which has a pivotal function in signal transduction during activation and control of the innate defense system. Preclinical data indicate that IDRs may be active in models of a wide range of therapeutic indications including life-threatening bacterial infections as well as the severe side-effects of chemo- and radiation-therapy. Additionally, due to selective binding to p62, dusquetide may have potential anti-tumor action.

Dusquetide has demonstrated efficacy in numerous animal disease models including mucositis, oncology, colitis, skin infection and other bacterial infections and has been evaluated in a double-blind, placebo-controlled Phase 1 clinical trial in 84 healthy volunteers with both single ascending dose and multiple ascending dose components. Dusquetide was shown to have a good safety profile and be well-tolerated in all dose groups when administered by IV over 7 days and was consistent with safety results seen in pre-clinical studies. We believe that market opportunities for dusquetide include, but are not limited to, oral and gastrointestinal mucositis, oncology (e.g., breast cancer), acute Gram-positive bacterial infections (e.g., methicillin resistant Staphylococcus aureus (“MRSA”)), acute Gram-negative infections (e.g., acinetobacter, melioidosis), and acute radiation syndrome.

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SGX945 – for Treating Aphthous Ulcers in Behçet’s Disease

SGX945 is our product candidate containing our IDR technology, dusquetide, targeting the treatment of aphthous ulcers in BD. BD is an orphan disease and an area of unmet medical need. The Phase 2a study completed in July 2025, which evaluated control of oral ulcers in BD, 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 BD 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.

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In January 2024, SGX945 received Fast Track designation from the FDA for the treatment of oral lesions of BD.

In August 2025, we received orphan drug designation from the FDA for the active ingredient in SGX945 (dusquetide) in the treatment of BD.

In December 2025, results from the Phase 2a proof of concept study evaluating SGX945 (dusquetide) in the treatment of BD were 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".

In February 2026, we received a positive recommendation from the EMA Committee for Orphan Medicinal Products on our request for orphan drug designation for SGX945 (dusquetide) for the treatment of BD following review of the recently published Phase 2a clinical results demonstrating biological efficacy and safety in patients with BD.

In March 2026, SGX945 (dusquetide) was granted PIM designation in the UK by the MHRA for the treatment of BD.

In March 2026, the European Commission granted orphan drug designation to SGX945 (dusquetide) for the treatment of BD.

We estimate the potential worldwide market for SGX945 is in excess of $200 million for the treatment of aphthous ulcers in BD. This potential market information is a forward-looking statement, and investors are urged not to place undue reliance on this statement. While we have determined this potential market size based on assumptions that we believe are reasonable, there are a number of factors that could cause our expectations to change or not be realized.

Behçet’s Disease

BD 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),

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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.

BD 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 BD in the U.S. and 80,000 in Europe. There are as many as 1,000,000 people worldwide living with BD.

There is no cure for BD, rather treatments are prescribed to manage symptoms. Treatments may include both maintenance therapies and those specifically addressing mucocutaneous 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 BD 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 BD is apremilast, which is used as a maintenance therapy to prevent formation of oral ulcers. Unfortunately, apremilast is associated with both high cost and side effects including diarrhea, nausea, upper respiratory tract infection and headache.

SGX942 – for Treating Oral Mucositis in Head and Neck Cancer

SGX942 is our product candidate containing our IDR technology, dusquetide, targeting the treatment of oral mucositis in head and neck cancer patients. Oral mucositis in this patient population is an area of unmet medical need where there are currently no approved drug therapies. Accordingly, we received Fast Track designation for the treatment of oral mucositis as a result of radiation and/or chemotherapy treatment in head and neck cancer patients from the FDA. In addition, dusquetide has been granted PIM designation in the UK by the MHRA for the treatment of SOM in head and neck cancer patients receiving chemoradiation therapy.

In a Phase 2 proof-of-concept clinical study that enrolled 111 patients, SGX942, at a dose of 1.5 mg/kg, successfully reduced the median duration of SOM by 50%, from 18 days to 9 days (p=0.099) in all patients and by 67%, from 30 days to 10 days (p=0.040) in patients receiving the most aggressive chemoradiation therapy for treatment of their head and neck cancer. The p-values met the prospectively defined statistical threshold of p<0.1 in the study protocol. A less severe occurrence of oral mucositis, ulcerative oral mucositis (defined as oral mucositis with a WHO score ≥2 corresponding to the occurrence of overt ulceration in the mouth), was also monitored during the study. In the patients receiving the most aggressive chemoradiation therapy, the median duration of oral mucositis was found to decrease from 65 days in the placebo treated patients to 51 days in the patients treated with SGX942 1.5 mg/kg (p=0.099).

In addition to identifying the best dose of 1.5 mg/kg, this study achieved all objectives, including increased incidence of “complete response” of tumor at the one month follow-up visit (47% in placebo vs. 63% in SGX942 at 1.5 mg/kg). Decreases in mortality and decreases in infection rate were also observed with SGX942 treatment, consistent with the preclinical results observed in animal models. Data from this Phase 2 trial are published in the Journal of Biotechnology.

SGX942 was found to be generally safe and well tolerated, consistent with the safety profile observed in the prior Phase 1 study conducted in 84 healthy volunteers. The long-term (12 month) follow-up data was consistent with the preliminary positive safety and efficacy findings. While the placebo population experienced the expected 12-month survival rate of approximately 80%, as defined in the Surveillance, Epidemiology, and End Results statistics 1975-2012 from the National Cancer Institute, the SGX942 1.5 mg/kg treatment group reported a 12-month survival rate of 93% (7% mortality in the SGX942 1.5 mg/kg group compared to 19% in the placebo group). Similarly, tumor resolution (complete response) at 12 months was better in the SGX942 1.5 mg/kg treatment group relative to the placebo population (80% in the 1.5 mg/kg group compared to 74% in the placebo group). The long-term follow-up results from the Phase 2 study are published in Biotechnology Reports.

In September 2016, we and SciClone Pharmaceuticals, Inc. (“SciClone”) entered into an exclusive license agreement, pursuant to which we granted rights to SciClone to develop, promote, market, distribute and sell SGX942 in defined territories. Under the terms of the license agreement, SciClone will be responsible for all aspects of development, product registration and commercialization in the territories, having access to data generated by us. In exchange for exclusive rights,

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SciClone will pay us royalties on net sales, and we will supply commercial drug product to SciClone on a cost-plus basis, while maintaining worldwide manufacturing rights.

Based on the positive and previously published Phase 2 results, we conducted a Phase 3 clinical trial referred to as the “DOM–INNATE” (Dusquetide treatment in Oral Mucositis – by modulating INNATE immunity) study. The Phase 3 protocol was a double-blind, randomized, placebo-controlled, multinational trial that sought to enroll approximately 260 subjects with squamous cell carcinoma of the oral cavity and oropharynx who were scheduled to receive a minimum total cumulative radiation dose of 55 Gy fractionated as 2.0-2.2 Gy per day with concomitant cisplatin chemotherapy given as a dose of 80-100 mg/m2 every third week. Subjects were randomized to receive either 1.5 mg/kg SGX942 or placebo given twice a week during and for two weeks following completion of chemoradiation therapy (“CRT”). The primary endpoint for the study was the median duration of SOM, which was assessed by oral examination at each treatment visit and then through six weeks following completion of CRT. Oral mucositis is evaluated using the WHO Grading system. SOM is defined as a WHO Grade of ≥3. Subjects are followed for an additional 12 months after the completion of treatment.

The results of the study showed that the primary endpoint of median duration of SOM did not achieve the pre-specified criterion for statistical significance (p≤0.05); although biological activity was observed with a 56% reduction in the median duration of SOM from 18 days in the placebo group to 8 days in the SGX942 treatment group. Despite this clinically meaningful improvement, the variability in the distribution of the data yielded a p-value that was not statistically significant. Other secondary endpoints supported the biological activity of dusquetide, including a statistically significant 50% reduction in the median duration of SOM in the per-protocol population, which decreased from 18 days in the placebo group to 9 days in the SGX942 treatment group (p=0.049), consistent with the findings in the Phase 2 trial (Study IDR-OM-01). Similarly, incidence of SOM also followed this biological trend as seen in the Phase 2 study, decreasing by 16% in the SGX942 treatment group relative to the placebo group in the per-protocol population. The per-protocol population was defined as the population receiving a minimum of 55 Gy radiation and at least 10 doses of study drug (placebo or SGX942) throughout the intended treatment period, with no major protocol deviations (e.g. breaks in study drug administration longer than 8 days between successive doses).

Following analysis of the full dataset, including the 12-month long-term follow-up safety data in late 2021, we held a meeting with the MHRA to review the study results and to obtain further clarity on the future of the oral mucositis development program. The meeting was informative with the outcome being that based on the SGX942 biologic activity observed and the consistency in response between the Phase 2 and Phase 3 trials, the Phase 3 DOM-INNATE study could serve as the first of two Phase 3 studies required to support potential marketing authorization, assuming the second Phase 3 clinical trial achieves the required level of statistical significance in its primary endpoint. With the benefit of a robust preclinical and clinical data package for SGX942, we now will analyze the data to design a second Phase 3 study and will look to identify a potential partner(s) to continue this development program.

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In January 2022, dusquetide proved effective at reducing tumor size in nonclinical xenograft models. Recent studies, recapitulating results from previously published studies, have confirmed the efficacy of dusquetide as a stand-alone and combination anti-tumor therapy, with radiation, chemotherapy and targeted therapy, in the context of the MCF-7 breast cancer cell line. Of note, these results are consistent with a potential direct anti-tumor effect identified with SGX942 and is another important consideration in the oral mucositis treatment space.

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In June 2022, an article was published describing the binding of our IDR, dusquetide, to the p62 protein. Dusquetide binds to p62 or SQSTM-1, a scaffold protein implicated in a number of intracellular signaling networks implicated in tumor cell survival, including autophagy. This publication elaborates on the direct interaction of dusquetide with p62, as well as some of the direct downstream consequences of that interaction, consistent with its observed anti-infective, anti-tumor and anti-inflammatory activities. This information advances the understanding of dusquetide's novel mechanism of action and supports the development of analogs related to dusquetide.

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We estimate the potential worldwide market for SGX942 is in excess of $500 million for the treatment of oral mucositis. This potential market information is a forward-looking statement, and investors are urged not to place undue reliance on this statement. While we have determined this potential market size based on assumptions that we believe are reasonable, there are a number of factors that could cause our expectations to change or not be realized.

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Oral Mucositis

Mucositis is the clinical term for damage done to the mucosa by anticancer therapies. It can occur in any mucosal region, but is most commonly associated with the mouth, followed by the small intestine. We estimate, based upon our review of historic studies and reports, and an interpolation of data on the incidence of mucositis, that mucositis affects approximately 500,000 people in the U.S. per year and occurs in 40% of patients receiving chemotherapy. Mucositis can be severely debilitating and can lead to infection, sepsis, the need for parenteral nutrition and narcotic analgesia. The gastro-intestinal damage causes severe diarrhea. These symptoms can limit the doses and duration of cancer treatment, leading to sub-optimal treatment outcomes.

The mechanisms of mucositis have been extensively studied and have been linked to the interaction of chemotherapy and/or radiation therapy with the innate defense system. Bacterial infection of the ulcerative lesions is regarded as a secondary consequence of dysregulated local inflammation triggered by therapy-induced cell death, rather than as the primary cause of the lesions.

We estimate, based upon our review of historic studies and reports, and an interpolation of data on the incidence of oral mucositis, that oral mucositis is a subpopulation of approximately 90,000 patients in the U.S., with a comparable number in Europe. Oral mucositis almost always occurs in patients with head and neck cancer treated with radiation therapy (greater than 80% incidence of severe mucositis) and is common in patients undergoing high dose chemotherapy and hematopoietic cell transplantation, where the incidence and severity of oral mucositis depends greatly on the nature of the conditioning regimen used for myeloablation.

Public Health Solutions Overview

ThermoVax® – Thermostability Platform Technology

ThermoVax® is a novel method for thermostabilizing vaccines with a variety of adjuvants, resulting in a single vial which can be reconstituted with water for injection immediately prior to use. One of the adjuvants utilized in ThermoVax® is aluminum salts (known colloquially as “Alum”). Alum is the most widely employed adjuvant technology in the vaccine industry.

The value of ThermoVax® lies in its potential ability to eliminate the need for cold chain production, transportation, and storage for Alum-adjuvanted vaccines. This would relieve the high costs of producing and maintaining vaccines under refrigerated conditions. Based on historical reports from WHO and other scientific reports, we believe that a meaningful proportion of vaccine doses globally are wasted due to excursions from required cold chain temperature ranges. This is due to the fact that many vaccines need to be maintained either between 2 and 8 degrees Celsius (“C”), frozen below -20 degrees C, or frozen below -60 degrees C, and even brief excursions from these temperature ranges usually necessitate the destruction of the product or the initiation of costly stability programs specific for the vaccine lots in question. ThermoVax® has the potential to facilitate easier storage and distribution of strategic national stockpile vaccines for ricin exposure in emergency settings.

ThermoVax® development, specifically in the context of an Alum adjuvant, was supported pursuant to a previous $9.4 million NIAID grant which enabled development of thermo-stable ricin (RiVax®) and anthrax vaccines. Proof-of-concept preclinical studies with ThermoVax® indicate that it is able to produce stable vaccine formulations using adjuvants, protein immunogens, and other components that ordinarily would not withstand long temperature variations exceeding customary refrigerated storage conditions. These studies were conducted with our Alum-adjuvanted ricin toxin vaccine, RiVax® and our Alum-adjuvanted anthrax vaccine. Each vaccine was manufactured under precise lyophilization conditions using excipients that aid in maintaining native protein structure of the key antigen. When RiVax® was kept at 40 degrees C (104 degrees Fahrenheit (“F”)) for up to one year, all of the animals vaccinated with the lyophilized RiVax® vaccine developed potent and high titer neutralizing antibodies. In contrast, animals that were vaccinated with the liquid RiVax® vaccine kept at 40 degrees C did not develop neutralizing antibodies and were not protected against ricin exposure. The ricin A chain is extremely sensitive to temperature and rapidly loses the ability to induce neutralizing antibodies when exposed to temperatures higher than 8 degrees C. When the anthrax vaccine was kept for up to 16 weeks at 70 degrees C, it was able to develop a potent antibody response, unlike the liquid formulation kept at the same temperature. Moreover, we also have demonstrated the compatibility of our thermostabilization technology with other secondary adjuvants such as TLR-4 agonists.

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We also entered into a collaboration agreement with Axel Lehrer, PhD of the Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine (“JABSOM”), University of Hawai’i at Manoa (“UH Manoa”) and Hawaii Biotech, Inc. (“HBI”) to develop a heat stable subunit Ebola vaccine. Dr. Lehrer, a co-inventor of the Ebola vaccine with HBI, has shown proof of concept efficacy with subunit Ebola vaccines in non-human primates (“NHP”). The most advanced Ebola vaccines involve the use of vesicular stomatitis virus and adenovirus vectors – live, viral vectors which complicate the manufacturing, stability and storage requirements. Dr. Lehrer’s vaccine candidate is based on highly purified recombinant protein antigens, circumventing many of these manufacturing difficulties. Dr. Lehrer and HBI have developed a robust manufacturing process for the required proteins. Application of ThermoVax® may allow for a product that can avoid the need for cold chain distribution and storage, yielding a vaccine ideal for use in both the developed and developing world. This agreement has expired in accordance with its terms.

In March 2020, we entered into a research collaboration with Axel Lehrer, PhD of the Department of Tropical Medicine, Medical Microbiology and Pharmacology, JABSOM, UH Manoa to further expand the filovirus collaboration to investigation of potential coronavirus vaccines, including for SARS-CoV-2 (causing COVID-19). This research collaboration will utilize the technology platform developed in the search for filovirus vaccines and will use well-defined surface glycoprotein(s) from one or more coronaviruses, which are expected to be protective for COVID-19.

During April 2020, we obtained an exclusive worldwide license for CoVaccine HT™, a novel vaccine adjuvant, from SERB Pharmaceuticals (formerly BTG Specialty Pharmaceuticals, a division of Boston Scientific Corporation) (“SERB”), for the fields of coronavirus infection (including SARS-CoV-2, the cause of COVID-19), and pandemic flu. CoVaccine HT™ is a novel adjuvant, which has been shown to enhance both cell-mediated and antibody-mediated immunity. We and our collaborators, including UH Manoa and Dr. Axel Lehrer, have successfully demonstrated the utility of CoVaccine HT™ in the development of our heat stable filovirus vaccine program, with vaccine candidates against EBOV and MARV disease. Given this previous success, CoVaccine HT™ will potentially be an important component of our vaccine technology platform currently being assessed for use against coronaviruses including SARS-CoV-2, the cause of COVID-19. The license agreement was executed between us and SERB, which owns the CoVaccine HT™ intellectual property.

In September 2020, the Journal of Pharmaceutical Sciences published a scientific article detailing the thermostabilization of the filovirus GP proteins and key assays describing their stability.

During October 2020, Frontiers in Immunology published a scientific article describing CiVax™, a prototype COVID-19 vaccine, using the novel CoVaccine HT™ adjuvant and demonstrating significant immunogenicity, including strong total and neutralizing antibody responses, with a balanced Th1 response, as well as enhancement of cell mediated immunity. These are all considered to be critical attributes of a potential COVID-19 vaccine.

During August 2021, positive data demonstrated the efficacy of multiple filovirus vaccine candidates in NHP, including thermostabilized multivalent vaccines in a single vial platform presentation. Collaborators at UH Manoa describe the potent efficacy of vaccine candidates protecting against three life-threatening filoviruses, EBOV, SUDV and MARV in an article titled "Recombinant Protein Filovirus Vaccines Protect Cynomolgus Macaques from Ebola, Sudan, and Marburg Viruses", published in Frontiers in Immunology. These vaccine candidates contain highly purified protein antigens combined with the novel CoVaccine HT™ adjuvant, in both monovalent (single antigen) and bivalent (two antigen) formulations. Most recently, efforts to formulate all three antigens and adjuvant into a thermostable single-vial vaccine platform has also been shown to protect 75% of vaccinated NHPs against subsequent SUDV challenge, with further development to test efficacy against other filovirus infections ongoing.

During August 2021, Vaccine published a scientific article describing the formulation of single-vial platform presentations of monovalent (single antigen), bivalent (two antigens) and trivalent (three antigens) combinations of filovirus vaccine candidates.

In December 2021, 100% protection of NHPs against lethal SUDV challenge was achieved using a bivalent, thermostabilized vaccine formulated in a single vial, reconstituted only with water immediately prior to use. This milestone is part of an ongoing collaboration with UH Manoa and further demonstrates the broad applicability of the vaccine platform, and its potential role in the U.S. government's initiative for pandemic preparedness.

In May 2022, the U.S. Patent and Trademark Office issued a Notice of Allowance for the patent application titled “Composition and Methods of Manufacturing Trivalent Filovirus Vaccines.” The allowed claims are directed to unique, proprietary composition and methods directed to combinations of glycoprotein antigens with nano-emulsion adjuvants

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comprising sucrose fatty acid esters prior to lyophilization. The described vaccine platform has previously been successfully applied to filovirus vaccines (as mono-, bi- and tri-valent candidates for EBOV, SUDV and MARV) as well as SARS-CoV-2 vaccine. No currently licensed lyophilized vaccine that contains an adjuvant is presented in a single vial format and there are few reports of successfully using nano-emulsions in lyophilized formulations. Previous work has demonstrated the use of a single vial platform to co-lyophilize antigen(s) and a nano-emulsion adjuvant, CoVaccine HT™, maintaining key adjuvant stability characteristics including particle size and colloidal stability, as well as maintaining immunogenicity. This most recent milestone confirms that, in the context of lethal challenge with SUDV, complete protection is maintained with the thermostabilized formulation.

In June 2022, 100% protection of NHPs against lethal MARV challenge was achieved using a bivalent, thermostabilized vaccine formulated in a single vial, reconstituted only with sterile water immediately prior to use. This important milestone is part of an ongoing collaboration with UH Manoa, demonstrating the successful presentation of one or more antigen(s) within the same formulation while maintaining full potency and thermostability. It further demonstrates the broad applicability of the heat stable vaccine platform, and its potential role in the U.S. government's initiative for pandemic preparedness.

In September 2023, positive data demonstrated two-year stability of thermostabilized bivalent and trivalent filovirus vaccine candidates at temperatures of 40 degrees C (104 degrees F) when formulated in a single vial, needing reconstitution only with sterile water immediately prior to use. This important milestone is part of an ongoing collaboration with UH Manoa, demonstrating the successful presentation of one or more antigen(s) within the same formulation while maintaining full potency and thermostability. It further demonstrates the broad applicability of the heat stable vaccine platform, and its potential role in the U.S. government’s initiative for pandemic preparedness.

In January 2024, Vaccine published the preclinical efficacy results of our novel, single-vial, thermostabilized bivalent filovirus vaccine providing 100% protection against both SUDV and MARV infections. The manuscript was entitled “Thermostable bivalent filovirus vaccine protects against severe and lethal Sudan ebolavirus and marburgvirus infection”.

In April 2024, we received orphan drug designation for the active ingredient in SuVax™, the subunit protein vaccine of recombinantly expressed SUDV glycoprotein, for the prevention and post-exposure prophylaxis against SUDV infection.

In April 2024, we received orphan drug designation for the active ingredient in MarVax™, the subunit protein vaccine of recombinantly expressed MARV glycoprotein, for the prevention and post-exposure prophylaxis against MARV infection.

In April 2024, we received notice of intent to grant additional patents based on our patent application titled “Compositions and Methods of Manufacturing Trivalent Filovirus Vaccines” in the United Kingdom and South Africa, with other international jurisdictions pending.

In March 2025, we announced a publication describing the preclinical efficacy of CiVax™, a thermostabilized subunit vaccine against SARS-CoV-2. Using custom-developed immunoassays, the combination of a primary adenovirus vaccine (COVID-19 Vaccine AstraZeneca) coupled with a CiVax™ booster was shown to induce broader protection against COVID-19 variants in non-human primates than a 2-shot mRNA series (such as the Moderna vaccine Spikefax® or the Pfizer vaccine Cominarty®) in humans. In collaboration with Axel Lehrer, PhD, Professor at the Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaiʻi at Mānoa, the manuscript entitled "Use of a Multiplex Immunoassay Platform to Investigate Multifaceted Antibody Responses in SARS-CoV-2 Vaccinees with and Without Prior Infection", has been published in COVID.

In September 2025, we announced a publication describing the extended stability of filovirus vaccines using our ThermoVax® platform. Bivalent and trivalent vaccines, constructed from antigens against EBOV, SUDV and MARV and the CoVaccine HT™ antigen, were formulated in a single vial and subjected to long-term storage at up to 40°C (104°F). After two years of storage, all vaccines were unchanged and had equivalent potency as when initially manufactured. In collaboration with Axel Lehrer, PhD, Professor at the Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, UH Manoa, the manuscript entitled "Thermostable Bivalent & Trivalent Filovirus Vaccines from Insect Cells: Potency Demonstrated after 3 Months and 2 Years", has been accepted for publication and is available online in Vaccine.

As a vaccine for a neglected tropical disease, an FDA approved SuVax™, MarVax™ or combined vaccine has the potential to qualify for a Tropical Disease Priority Review Voucher (“PRV”). PRVs are transferable and can be sold, with sales in

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recent years of approximately $200 million. When redeemed, PRVs entitle the user to an accelerated review period of nine months, saving a median of seven months review time as calculated in 2009. However, FDA must be advised 90 days in advance of the use of the PRV and the use of a PRV is associated with an additional user fee (approximately $2.0 million for fiscal year 2026).

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RiVax® – for Protection Against Ricin Toxin Exposure

RiVax® is our proprietary vaccine candidate being developed to protect against exposure to ricin toxin and if approved, would be the first ricin vaccine. The immunogen in RiVax® induces a protective immune response in animal models of ricin exposure and functionally active antibodies in humans. The immunogen consists of a genetically inactivated ricin A chain subunit that is enzymatically inactive and lacks residual toxicity of the holotoxin. RiVax® has demonstrated statistically significant (p < 0.0001) preclinical survival results, providing 100% protection against acute lethality in an aerosol exposure non-human primate model (Roy et al, 2015, Thermostable ricin vaccine protects rhesus macaques against aerosolized ricin: Epitope-specific neutralizing antibodies correlate with protection, PNAS USA 112:3782-3787), and has also been shown to be well tolerated and immunogenic in two Phase 1 clinical trials in healthy volunteers. Results of the first Phase 1 human trial of RiVax® established that the immunogen was safe and induced antibodies that we believe may protect humans from ricin exposure. The antibodies generated from vaccination, concentrated and purified, were capable of conferring immunity passively to recipient animals, indicating that the vaccine was capable of inducing functionally active antibodies in humans. The outcome of this study was published in the Proceedings of the National Academy of Sciences (Vitetta et al., 2006, A Pilot Clinical Trial of a Recombinant Ricin Vaccine in Normal Humans, PNAS, 103:2268-2273). The second trial that was completed in September 2012 and was sponsored by University of Texas Southwestern Medical Center (“UTSW”) evaluated a more potent formulation of RiVax® that contained an Alum adjuvant. The results of the Phase 1b study indicated that Alum-adjuvanted RiVax® was safe and well tolerated, and induced greater ricin neutralizing antibody levels in humans than adjuvant-free RiVax®. The outcomes of this second study were published in the Clinical and Vaccine Immunology.

We have adapted the original manufacturing process for the immunogen contained in RiVax® for thermostability and large scale manufacturing and recent studies have confirmed that the thermostabilized RiVax® formulation enhances the stability of the RiVax® antigen, enabling storage for at least 1 year at temperatures up to 40 degrees C (104 degrees F). The program will pursue approval via the FDA “Animal Rule” since it is not possible to test the efficacy of the vaccine in a clinical study which would expose humans to ricin. Uniform, easily measured and species-neutral immune correlates of protection that can be measured in humans and animals, and are indicative of animal survival to subsequent ricin challenge, are central to the application of the “Animal Rule.” Recent work has identified such potential correlates of immune protection in animals and work to qualify and validate these approaches is continuing, with the goal of utilizing these assays in a planned Phase 1/2 clinical trial with the thermostable RiVax® formulation. During September 2018, we published an extended stability study of RiVax®, showing up to 100% protection in mice after 12 months storage at 40 degrees C (104 degrees F) as well as identification of a potential in vitro stability indicating assay, critical to adequately confirming the long-term shelf life of the vaccine. We have entered into a collaboration with IDT Biologika GmbH (“IDT”) to scale-up the formulation/filling process and continue development and validation of analytical methods established at IDT to advance the program. We also initiated a development agreement with Emergent BioSolutions, Inc. (“EBS”) to implement a commercially viable, scalable production technology for the RiVax® drug substance protein antigen.

The development of RiVax® has been sponsored through a series of overlapping challenge grants, UC1, and cooperative grants, U01, from the National Institutes of Health (“NIH”), granted to us and to UTSW where the vaccine originated. The second clinical trial was supported by a grant from the FDA’s Office of Orphan Products to UTSW. To date, we and UTSW have collectively received approximately $25 million in grant funding from the NIH for the development of RiVax®. In September 2014, we entered into a contract with the NIH for the development of RiVax® pursuant to which we were awarded an additional $21.2 million of funding in the aggregate. The development agreements with EBS and IDT were specifically funded under this NIH contract. No funds are remaining from any of these grants.

In November 2021, an article was published on pre-clinical immunogenicity studies for RiVax® demonstrating enduring protection for at least 12 months post-vaccination. These results, coupled with the previous demonstration of efficacy in mice and NHPs as well as long-term thermostability (at least 1 year at 40 degrees C or 104 degrees F), reinforce the practicality of stockpiling and potentially utilizing the RiVax® vaccine in warfighters and civilian first responders without the complexities that arise for vaccines that require stringent cold chain handling.

In December 2022, we published a paper demonstrating statistically significant correlates of protection predicting survival after lethal aerosolized ricin challenge in non-human primates. The article titled “Serum antibody profiling identifies vaccine-

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induced correlates of protection against aerosolized ricin toxin in rhesus macaques” was published in the journal npj Vaccines.

RiVax® has been granted Orphan Drug designation as well as Fast Track designation by the FDA for the prevention of ricin intoxication. In addition, RiVax® has also been granted Orphan Drug designation in the European Union (“EU”) from the EMA Committee for Orphan Medical Products.

Assuming development efforts are successful for RiVax®, we believe potential government procurement contract(s) could reach as much as $200 million. This potential procurement contract information is a forward-looking statement, and investors are urged not to place undue reliance on this statement. While we have determined this potential procurement contract value based on assumptions that we believe are reasonable, there are a number of factors that could cause our expectations to change or not be realized.

Ricin Toxin

Ricin toxin can be cheaply and easily produced, is stable over long periods of time, is toxic by several routes of exposure and thus has the potential to be used as a biological weapon against military and/or civilian targets. As a bioterrorism agent, ricin could be disseminated as an aerosol, by injection, or as a food supply contaminant. The potential use of ricin toxin as a biological weapon of mass destruction has been highlighted in a Federal Bureau of Investigation Bioterror report released in November 2007 titled Terrorism 2002-2005, which states that “Ricin and the bacterial agent anthrax are emerging as the most prevalent agents involved in WMD investigations.” Al Qaeda in the Arabian Peninsula had threatened the use of ricin toxin to poison food and water supplies and in connection with explosive devices. Domestically, the threat from ricin remains a concern for security agencies. In April 2013, letters addressed to the U.S. President, a Senator and a judge tested positive for ricin. As recently as September 2020, ricin-laced letters addressed to the White House and others addressed to Texas law enforcement agencies were intercepted before delivery raising fresh concerns about the deadly toxin.

The Centers for Disease Control and Prevention has classified ricin toxin as a Category B biological agent. Ricin works by first binding to glycoproteins found on the exterior of a cell, and then entering the cell and inhibiting protein synthesis leading to cell death. Once exposed to ricin toxin, there is no effective therapy available to reverse the course of the toxin. The recent ricin threat to government officials has heightened the awareness of this toxic threat. Currently, there is no FDA approved vaccine to protect against the possibility of ricin toxin being used in a terrorist attack, or its use as a weapon on the battlefield nor is there a known antidote for ricin toxin exposure.

SGX943 – for Treating Emerging and/or Antibiotic-Resistant Infectious Diseases

SGX943 is an IDR, containing the same active ingredient as SGX942. Dusquetide is a fully synthetic, 5-amino acid peptide with high aqueous solubility and stability. Extensive in vivo preclinical studies have demonstrated enhanced clearance of bacterial infection with SGX943 administration. SGX943 has shown efficacy against both Gram-negative and Gram-positive bacterial infections in preclinical models, independent of whether the bacteria is antibiotic-resistant or antibiotic-sensitive.

The innate immune system is responsible for rapid and non-specific responses to combat bacterial infection. Augmenting these responses represents an alternative approach to treating bacterial infections. In animal models, IDRs are efficacious against both antibiotic-sensitive and antibiotic-resistant infections, both Gram-positive and Gram-negative bacteria, and are active irrespective of whether the bacteria occupy a primarily extracellular or intracellular niche. IDRs are also effective as stand-alone agents or in conjunction with antibiotics. An IDR for the treatment of serious bacterial infections encompasses a number of clinical advantages including:

●Treatment when antibiotics are contraindicated, such as:

o

before the infectious organism and/or its antibiotic susceptibility is known; or

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in at-risk populations prior to infection.

●An ability to be used as an additive, complementary treatment with antibiotics, thereby:

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enhancing efficacy of sub-optimal antibiotic regimens (e.g., partially antibiotic-resistant infections);

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enhancing clearance of infection, thereby minimizing the generation of antibiotic resistance (e.g., in treating melioidosis); and

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reducing the required antibiotic dose, again potentially minimizing the generation of antibiotic resistance.

●An ability to modulate the deleterious consequences of inflammation in response to the infection, including the inflammation caused by antibiotic-driven bacterial lysis.

●Being unlikely to generate bacterial resistance since the IDR acts on the host, and not the pathogen.

Importantly, systemic inflammation and multi-organ failure is the ultimate common outcome of not only emerging and/or antibiotic-resistant infectious diseases, but also of most biothreat agents (e.g., Burkholderia pseudomallei), indicating that dusquetide would be applicable not only to antibiotic-resistant infection, but also to biothreat agents, especially where the pathogen is not known and/or has been engineered for enhanced antibiotic resistance.

The Drug Approval Process

The FDA and comparable regulatory agencies in state, local and foreign jurisdictions impose substantial requirements on the clinical development, manufacture and marketing of new drug and biologic products. The FDA, through regulations that implement the Federal Food, Drug, and Cosmetic Act, as amended (“FDCA”), and other laws and comparable regulations for other agencies, regulate research and development activities and the testing, manufacture, labeling, storage, shipping, approval, recordkeeping, advertising, promotion, sale, export, import and distribution of such products. The regulatory approval process is generally lengthy, expensive and uncertain. Failure to comply with applicable FDA and other regulatory requirements can result in sanctions being imposed on us or the manufacturers of our products, including holds on clinical research, civil or criminal fines or other penalties, product recalls, or seizures, or total or partial suspension of production or injunctions, refusals to permit products to be imported into or exported out of the U.S., refusals of the FDA to grant approval of drugs or to allow us to enter into government supply contracts, withdrawals of previously approved marketing applications and criminal prosecutions.

Before human clinical testing in the U.S. of a new drug compound or biological product can commence, an IND application is required to be submitted to the FDA. The IND application includes results of pre-clinical animal studies evaluating the safety and efficacy of the drug and a detailed description of the clinical investigations to be undertaken.

Clinical trials are normally done in three phases, although the phases may overlap. Phase 1 trials are smaller trials concerned primarily with metabolism and pharmacologic actions of the drug and with the safety of the product. Phase 2 trials are designed primarily to demonstrate effectiveness and safety in treating the disease or condition for which the product is indicated. These trials typically explore various doses and regimens. Phase 3 trials are expanded clinical trials intended to gather additional information on safety and effectiveness needed to clarify the product’s benefit-risk relationship and generate information for proper labeling of the drug, among other things. The FDA receives reports on the progress of each phase of clinical testing and may require the modification, suspension or termination of clinical trials if an unwarranted risk is presented to patients. When data is required from long-term use of a drug following its approval and initial marketing, the FDA can require Phase 4, or post-marketing, studies to be conducted.

With certain exceptions, once successful clinical testing is completed, the sponsor can submit a NDA, for approval of a drug, or a Biologic License Application (“BLA”), for biologics such as vaccines, which will be reviewed, and if successful, approved by the FDA, allowing the product to be marketed. The process of completing clinical trials for a new drug is likely to take a number of years and require the expenditure of substantial resources. Furthermore, the FDA or any foreign health authority may not grant an approval on a timely basis, if at all. The FDA may deny the approval of a NDA or BLA, in its sole discretion, if it determines that its regulatory criteria have not been satisfied or may require additional testing or information. Among the conditions for marketing approval is the requirement that the prospective manufacturer’s quality control and manufacturing procedures conform to good manufacturing practice regulations. In complying with standards contained in these regulations, manufacturers must continue to expend time, money and effort in the area of production, quality control and quality assurance to ensure full technical compliance. Manufacturing facilities, both foreign and domestic, also are subject to inspections by, or under the authority of, the FDA and by other federal, state, local or foreign agencies.

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Even after initial FDA or foreign health authority approval has been obtained, further studies, including Phase 4 post-marketing studies, may be required to provide additional data on safety and will be required to gain approval for the marketing of a product as a treatment for clinical indications other than those for which the product was initially tested. For certain drugs intended to treat serious, life-threatening conditions that show great promise in earlier testing, the FDA can also grant conditional approval. However, drug developers are required to study the drug further and verify clinical benefit as part of the conditional approval provision, and the FDA can revoke approval if later testing does not reproduce previous findings. The FDA may also condition approval of a product on the sponsor agreeing to certain mitigation strategies that can limit the unfettered marketing of a drug. Also, the FDA or foreign regulatory authority will require post-marketing reporting to monitor the side effects of the drug. Results of post-marketing programs may limit or expand the further marketing of the product. Further, if there are any modifications to the drug, including any change in indication, manufacturing process, labeling or manufacturing facility, an application seeking approval of such changes will likely be required to be submitted to the FDA or foreign regulatory authority.

In the U.S., the FDCA, the Public Health Service Act, the Federal Trade Commission Act, and other federal and state statutes and regulations govern, or influence the research, testing, manufacture, safety, labeling, storage, record keeping, approval, advertising and promotion of drug, biological, medical device and food products. Noncompliance with applicable requirements can result in, among other things, fines, recall or seizure of products, refusal to permit products to be imported into the U.S., refusal of the government to approve product approval applications or to allow us to enter into government supply contracts, withdrawal of previously approved applications and criminal prosecution. The FDA may also assess civil penalties for violations of the FDCA involving medical devices.

For biodefense development, such as with RiVax®, the FDA has instituted policies that are expected to result in shorter pathways to market. This potentially includes approval for commercial use utilizing the results of animal efficacy trials, rather than efficacy trials in humans. However, we will still have to establish that the vaccine and countermeasures it is developing are safe in humans at doses that are correlated with the beneficial effect in animals. Such clinical trials will also have to be completed in distinct populations that are subject to the countermeasures; for instance, the very young and the very old, and in pregnant women, if the countermeasure is to be licensed for civilian use. Other agencies will have an influence over the benefit-risk scenarios for deploying the countermeasures and in establishing the number of doses utilized in the Strategic National Stockpile. We may not be able to sufficiently demonstrate the animal correlation to the satisfaction of the FDA, as these correlates are difficult to establish and are often unclear. Invocation of the animal rule may raise issues of confidence in the model systems even if the models have been validated. For many of the biological threats, the animal models are not available and we may have to develop the animal models, a time-consuming research effort. There are few historical precedents, or recent precedents, for the development of new countermeasure for bioterrorism agents. Despite the animal rule, the FDA may require large clinical trials to establish safety and immunogenicity before licensure and it may require safety and immunogenicity trials in additional populations. Approval of biodefense products may be subject to post-marketing studies, and could be restricted in use in only certain populations.

Vaccines are approved under the BLA process that exists under the Public Health Service Act. In addition to the greater technical challenges associated with developing biologics, the potential for generic competition is lower for a BLA product than a small molecule product subject to a NDA under the Federal Food, Drug and Cosmetic Act. Under the Patient Protection and Affordable Care Act enacted in 2010, a “generic” version of a biologic is known as a biosimilar and the barriers to entry – whether legal, scientific, or logistical – for a biosimilar version of a biologic approved under a BLA are higher.

Orphan Drug Designation

Under the Orphan Drug Act, the FDA may grant orphan drug designation to drugs or biologics intended to treat a rare disease or condition – generally a disease or condition that affects fewer than 200,000 individuals in the U.S. Orphan drug designation must be requested before submitting a NDA or BLA. After the FDA grants orphan drug designation, the generic identity of the drug or biologic and its potential orphan use are disclosed publicly by the FDA. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The first NDA or BLA applicant to receive FDA approval for a particular active ingredient to treat a particular disease with FDA orphan drug designation is entitled to a seven-year exclusive marketing period in the U.S. for that product, for that indication. During the seven-year exclusivity period, the FDA may not approve any other applications to market the same drug or biologic for the same disease, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same

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disease or condition, or the same drug or biologic for a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the NDA or BLA application user fee.

Fast Track Designation and Accelerated Approval

The FDA is required to facilitate the development, and expedite the review, of drugs or biologics that are intended for the treatment of a serious or life-threatening disease or condition for which there is no effective treatment and which demonstrate the potential to address unmet medical needs for the condition. Under the fast track program, the sponsor of a new drug or biologic candidate may request that the FDA designate the candidate for a specific indication as a fast track drug or biologic concurrent with, or after, the filing of the IND for the candidate. The FDA must determine if the drug or biologic candidate qualifies for fast track designation within 60 days of receipt of the sponsor’s request. Unique to a fast track product, the FDA may initiate review of sections of a fast track product’s NDA or BLA before the application is complete. This rolling review is available if the applicant provides, and the FDA approves, a schedule for the submission of the remaining information and the applicant pays applicable user fees. However, the FDA’s time period goal for reviewing an application does not begin until the last section of the NDA or BLA is submitted. Additionally, the fast track designation may be withdrawn by the FDA if the FDA believes that the designation is no longer supported by data emerging in the clinical trial process.

Any product submitted to the FDA for marketing, including under a fast track program, may be eligible for other types of FDA programs intended to expedite development and review, such as accelerated approval. Drug or biological products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may receive accelerated approval, which means the FDA may approve the product based upon a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments.

In clinical trials, a surrogate endpoint is a measurement of laboratory or clinical signs of a disease or condition that substitutes for a direct measurement of how a patient feels, functions, or survives. Surrogate endpoints can often be measured more easily or more rapidly than clinical endpoints. A drug or biologic candidate approved on this basis is subject to rigorous post-marketing compliance requirements, including the completion of Phase 4 or post-approval clinical trials to confirm the effect on the clinical endpoint. Failure to conduct required post-approval studies, or confirm a clinical benefit during post-marketing studies, will allow the FDA to withdraw the drug or biologic from the market on an expedited basis. All promotional materials for drug candidates approved under accelerated regulations are subject to prior review by the FDA.

Pediatric Information

Under the Pediatric Research Equity Act (“PREA”), NDAs or BLAs or supplements to NDAs or BLAs must contain data to assess the safety and effectiveness of the drug for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the drug is safe and effective. The FDA may grant full or partial waivers, or deferrals, for submission of data. Unless otherwise required by regulation, PREA does not apply to any drug for an indication for which orphan designation has been granted.

Paediatric Investigation Plan

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As part of the regulatory process for the registration of new medicines with the EMA and the MHRA, pharmaceutical companies are required to provide a PIP outlining our strategy for investigation of the new medicinal products in the paediatric population. In some instances, a waiver negating the need for a PIP for certain conditions may be granted by the EMA or MHRA when development of a medicine for use in children is not feasible or appropriate.

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Innovative Licensing and Access Pathway

​

The ILAP was launched in the UK at the start of 2021 to accelerate the development and access to promising medicines, thereby facilitating patient access to new medicines. The pathway, part of the UK’s plan to attract life sciences development in the post-Brexit era, features enhanced input and interactions with the MHRA and other stakeholders including the NICE, and the SMC. The decision to award the Innovation Passport is made by an ILAP Steering Group, which is comprised of

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representatives from MHRA, NICE, and SMC. The Innovation Passport designation is the first step in the ILAP process and triggers the MHRA and its partner agencies to create a target development profile to chart out a roadmap for regulatory and development milestones with the goal of early patient access in the UK. Other benefits of ILAP include a 150-day accelerated assessment, rolling review and a continuous benefit risk assessment.

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Early Access to Medicines Scheme

Launched in April 2014 in the United Kingdom by the MHRA, the Early Access to Medicines Scheme (“EAMS”) offers severely ill patients with life-threatening and seriously debilitating conditions the lifeline of trying ground-breaking new medicines earlier than they would normally be accessible. PIM designation is the first phase of EAMS and is awarded following an assessment of early nonclinical and clinical data by the MHRA. The criteria product candidates must meet to obtain PIM designation are:

●Criterion 1 – The condition should be life-threatening or seriously debilitating with a high unmet medical need (i.e., there is no method of treatment, diagnosis or prevention available or existing methods have serious limitations).

●Criterion 2 – The medicinal product is likely to offer major advantage over methods currently used in the UK.

●Criterion 3 – The potential adverse effects of the medicinal product are likely to be outweighed by the benefits, allowing for the reasonable expectation of a positive benefit risk balance. A positive benefit risk balance should be based on preliminary scientific evidence that the safety profile of the medicinal product is likely to be manageable and acceptable in relation to the estimated benefits.

False Claims Laws

The federal False Claims Act prohibits, among other things, any person or entity from knowingly presenting, or causing to be presented, a false claim for payment to, or approval by, the federal government or knowingly making, using, or causing to be made or used a false record or statement material to a false or fraudulent claim to the federal government. As a result of a modification made by the Fraud Enforcement and Recovery Act of 2009, a claim includes “any request or demand” for money or property presented to the U.S. government.

Anti-Kickback Laws

The federal Anti-Kickback Statute prohibits, among other things, any person or entity, from knowingly and willfully offering, paying, soliciting or receiving any remuneration, directly or indirectly, overtly or covertly, in cash or in kind, to induce or in return for purchasing, leasing, ordering or arranging for the purchase, lease or order of any item or service reimbursable under Medicare, Medicaid or other federal healthcare programs. The term remuneration has been interpreted broadly to include anything of value. The Anti-Kickback Statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, and formulary managers on the other.

United States Healthcare Reform

Federal Physician Payments Sunshine Act and its implementing regulations require that certain manufacturers of drugs, devices, biological and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions) to report information related to certain payments or other transfers of value made or distributed to physicians and teaching hospitals, or to entities or individuals at the request of, or designated on behalf of, the physicians and teaching hospitals and to report annually certain ownership and investment interests held by physicians and their immediate family members.

In addition, we may be subject to data privacy and security regulation by both the federal government and the states in which we conduct our business. The Health Insurance Portability and Accountability Act (“HIPAA”), as amended by the Health Information Technology for Economic and Clinical Health Act (“HITECH”), and its implementing regulations, imposes certain requirements relating to the privacy, security and transmission of individually identifiable health information. Among other things, HITECH makes HIPAA’s privacy and security standards directly applicable to “business associates” – independent contractors or agents of covered entities that receive or obtain protected health information in connection with providing a service on behalf of a covered entity. HITECH also created four new tiers of civil monetary penalties, amended

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HIPAA to make civil and criminal penalties directly applicable to business associates and possibly other persons, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorneys’ fees and costs associated with pursuing federal civil actions. In addition, state laws govern the privacy and security of health information in certain circumstances, many of which differ from each other in significant ways and may not have the same effect, thus complicating compliance efforts.

Third-Party Suppliers and Manufacturers

Drug substance and drug product manufacturing is outsourced to qualified suppliers. We do not have manufacturing capabilities/infrastructure and do not intend to develop the capacity to manufacture drug products substances. We have agreements with third-party manufacturers to supply bulk drug substances for our product candidates and with third parties to formulate, package and distribute our product candidates. Our employees include professionals with expertise in pharmaceutical manufacturing development, quality assurance and third-party supplier management who oversee work conducted by third-party companies. We believe that we have on hand or can easily obtain sufficient amounts of product candidates to complete our currently contemplated clinical trials. All of the drug substances used in our product candidates currently are manufactured by single suppliers. While we have not experienced any supply disruptions, the number of manufacturers of the drug substances is limited. In the event it is necessary or advisable to acquire supplies from alternative suppliers, assuming commercially reasonable terms could be reached, the challenge would be the efficient transfer of technology and know-how from current manufacturers to the new supplier. Formulation and distribution of our finished product candidates also currently are conducted by single suppliers but we believe that alternative sources for these services are readily available on commercially reasonable terms, subject to the efficient transfer of technology and know-how from current suppliers to the new supplier.

All of the current agreements for the supply of bulk drug substances for our product candidates and for the formulation or distribution of our product candidates relate solely to the development (including preclinical and clinical) of our product candidates. Under these contracts, our product candidates are manufactured upon our order of a specific quantity. In the event that we obtain marketing approval for a product candidate, we will qualify secondary suppliers for all key manufacturing activities supporting the marketing application.

Marketing and Collaboration

We do not currently have any sales and marketing capability, other than to potentially market our biodefense vaccine products directly to government agencies. With respect to other commercialization efforts, we currently intend to seek distribution and other collaboration arrangements for the sales and marketing of any product candidate that is approved, while also evaluating the potential to commercialize on our own in orphan disease indications. From time to time, we have had and are having strategic discussions with potential collaboration partners for our biodefense vaccine product candidates, although no assurance can be given that we will be able to enter into one or more collaboration agreements for our product candidate on acceptable terms, if at all. We believe that both military and civilian health authorities of the U.S. and other countries will increase their stockpiling of therapeutics and vaccines to treat and prevent diseases and conditions that could ensue following a bioterrorism attack.

On August 25, 2013, we entered into an agreement with SciClone, pursuant to which SciClone provided us with access to its oral mucositis clinical and regulatory data library in exchange for exclusive commercialization rights for SGX942 in the People’s Republic of China, including Hong Kong and Macau, subject to the negotiation of economic terms. SciClone’s data library was generated from two sequential Phase 2 clinical studies conducted in 2010 and 2012 evaluating SciClone’s compound, SCV-07, for the treatment of oral mucositis caused by chemoradiation therapy in head and neck cancer patients, before SciClone terminated its program. By analyzing data available from the placebo subjects in the SciClone trials, we acquired valuable insight into disease progression, along with quantitative understanding of its incidence and severity in the head and neck cancer patient population. This information assisted us with the design of the SGX942 Phase 2 clinical trial, in which positive preliminary results were announced in December 2015.

On September 9, 2016, we and SciClone entered into an exclusive license agreement, pursuant to which we granted rights to SciClone to develop, promote, market, distribute and sell SGX942 in the People’s Republic of China, including Hong Kong and Macau, as well as Taiwan, South Korea and Vietnam. Under the terms of the license agreement, SciClone will be responsible for all aspects of development, product registration and commercialization in the territories, having access to data generated by us. In exchange for exclusive rights, SciClone will pay us royalties on net sales, and we will supply commercial drug product to SciClone on a cost-plus basis, while maintaining worldwide manufacturing rights. We also

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entered into a common stock purchase agreement with SciClone pursuant to which we sold 1,471 shares of our common stock to SciClone for approximately $2,040 per share, for an aggregate price of approximately $3 million.

Competition

Our competitors are pharmaceutical and biotechnology companies, most of whom have considerably greater financial, technical, and marketing resources than we do. Universities and other research institutions, including the U.S. Army Medical Research Institute of Infectious Diseases, also compete in the development of treatment technologies, and we face competition from other companies to acquire rights to those technologies.

HyBryte™ Competition

There is currently no approved cure for CTCL and treatments are prescribed to manage symptoms. The FDA has approved several treatments for later stages (IIB-IV) of CTCL and/or in conditions that are unresponsive to prior treatment. Three are targeted therapies (Targretin®-caps, Ontak® and Adcetris®), two are histone deacetylases inhibitors (Zolina® and Istodax®) and the remaining two are topical therapies (Valchor® and Targretin®-gel). There are currently no FDA approved therapies for the treatment of front-line, early stage (I-IIA) CTCL; however certain topical chemotherapies and topical, radiation, photodynamic and other therapies which are approved for indications other than CTCL are prescribed off-label for the treatment of early stage CTCL. These include narrow-band ultraviolet B (NB-UVB) light therapy and psoralen combined with ultraviolet A UVA light therapy (“PUVA”); however, PUVA treatments are usually limited to three times per week and 200 times in total due to the potentially carcinogenic side effect, while NB UVB is known to be effective against patches but less so against plaque lesions, common in early stage CTCL. There are other drugs currently in development that may have the potential to be used in early stage (I-IIA) CTCL, primarily in early Phase 1 and 2 clinical studies. Other treatments for later stage disease are not considered direct competitors.

SGX302 Competition

There is currently no approved cure for psoriasis and treatments are prescribed to manage symptoms. The FDA has approved several topical and systemic treatments for psoriasis. Systemic therapies dominate the treatment of severe and increasingly the more severe moderate patients, and include biologics aimed at reducing systemic inflammation. Skin directed therapy remains the primary treatment for mild-to-moderate disease. Current therapies for mild-to-moderate disease include PUVA, (a photodynamic therapy), emollients, topical steroids, vitamin D preparations including retinoids (e.g., Sorilux®, Dovonex®, Cacitrene®), coal tar, salicylic acid, calcineurin inhibitors (e.g., Prograf®, Elidel®, Zorac®, Tazorac®) and dithranols (e.g., Drithocreme®). Other phototherapy approaches include the use of both broad-band and narrow-band ultraviolet B light. There are also a number of ongoing Phase 2 and 3 clinical trials in mild to moderate psoriasis.

Compared to PUVA, photoactivated hypericin uses non-carcinogenic and more penetrative visible light (unlike ultraviolet light used with PUVA) and a non-mutagenic compound hypericin (unlike psoralen used with PUVA), and is more highly targeted and more commensurate with long-term treatment. Compared to other skin-directed therapies, photoactivated hypericin has demonstrated a comparatively low local irritancy/adverse event rate with minimal long-term skin effects. Compared to systemic therapies, commonly used in more severe patients only, photoactivated hypericin does not cause immunosuppression.

SGX94/942/945 Competition

Because SGX94 (dusquetide) uses a novel mechanism of action in combating bacterial infections, there are no direct competitors at this time. Bacterial infections are routinely treated with antibiotics and SGX94 treatment is anticipated to be utilized primarily where antibiotics are insufficient (e.g., due to antibiotic resistance) or contra-indicated (e.g., in situations where the development of antibiotic resistance is a significant concern). Many groups are working on the antibiotic resistance problem and research into the innate immune system is intensifying, making emerging competition likely (from companies such as Qu Biologics Inc., Innaxon Therapeutics and Innate Pharma SA).

There is currently one drug approved for the treatment of oral mucositis in hematological cancer (palifermin). There are currently no approved drugs for treatment of oral mucositis in cancers with solid tumors (e.g., head and neck cancer). There are drugs in clinical development for oral mucositis – the most advanced listed is brilacidin by Innovation Pharmaceuticals, Inc. There are various natural products in small and/or open label studies (including sage, turmeric, honey and olive oil). In

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addition, there are medical devices approved for the treatment of oral mucositis including MuGard®, GelClair®, Episil®, and Caphosol®. These devices attempt to create a protective barrier around the oral ulceration with no biologic activity in treating the underlying disease.

There is currently no approved cure for BD and treatments are prescribed to manage symptoms. Treatments may include both maintenance therapies and those specifically addressing mucocutaneous 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, corticosteroids have limited efficacy over the long-term and have significant side effects that become more concerning with more chronic use. Other treatments for BD 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. For skin and mucosal manifestations of BD, anti-inflammatory drugs are also used, including colchicine, azathioprine, anti-TNF, anti-interferon alpha, anti-IL-17 and anti-IL-23 medications. The only approved drug in BD is apremilast, which is used as a maintenance therapy to prevent formation of oral ulcers. Apremilast is associated with both high cost and side effects including diarrhea, nausea, upper respiratory tract infection and headache.

ThermoVax® Competition

Multiple groups and companies are working to address the unmet need of vaccine thermostability using a variety of technologies. In addition, other organizations, such as the Bill and Melinda Gates Foundation and PATH, have programs designed to advance technologies to address this need.

Several stabilization technologies currently being developed involve mixing vaccine antigen +/- adjuvant with various proprietary excipients or co-factors that either serve to stabilize the vaccine or biological product in a liquid or dried (lyophilized) form. Examples of these approaches include the use of various plant-derived sugars and macromolecules being developed by companies such as iosBio. Variation Biotechnologies, Inc. (“VBI”) is developing a lipid system (resembling liposomes) to stabilize viral antigens, including virus-like particles (“VLPs”), and for potential application to a conventional influenza vaccine among others.

Additionally, companies like Panacea Biotec Ltd. are developing proprietary vaccines with the application of some form of stabilization technology.

Public Health Solutions Competition

We face competition in the area of biodefense product development from various public and private companies, universities and governmental agencies, such as the U.S. Army, some of whom may have their own proprietary technologies which may directly compete with our technologies.

The U.S. Army Medical Research Institute of Infectious Diseases, the DoD’s lead laboratory for medical research to counter biological threats is also developing a ricin vaccine candidate, RVEc™. RVEc™ has been shown to be fully protective in mice exposed to lethal doses of ricin toxin by the aerosol route. Further studies, in both rabbits and nonhuman primates, were conducted to evaluate RVEc™’s safety as well as its immunogenicity, with positive results observed. No further data has been released in recent years. A monoclonal antibody is also being developed by Mapp Biopharmaceutical Inc. as a ricin therapeutic, with administration 4 hours after exposure demonstrating efficacy while administration 12 hours after ricin exposure was not protective in animal models.

There are no approved vaccines to prevent infection and/or mitigate exposure to SUDV or MARV. There are other vaccine candidates in development, primarily using viral-vectored vaccine platforms. These platforms may be contra-indicated in the immune-compromised, pregnant individuals or children. They may also have limited efficacy on repeat administration.

Patents and Other Proprietary Rights

Our goal is to obtain, maintain and enforce patent protection for our products, formulations, processes, methods and other proprietary technologies, preserve our trade secrets, and operate without infringing on the proprietary rights of other parties, both in the U.S. and in other countries. Our policy is to actively seek to obtain, where appropriate, the broadest intellectual

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property protection possible for our product candidates, proprietary information and proprietary technology through a combination of contractual arrangements and patents, both in the U.S. and elsewhere in the world.

We also depend upon the skills, knowledge and experience of our scientific and technical personnel, as well as that of our advisors, consultants and other contractors, none of which is patentable. To help protect our proprietary knowledge and experience that is not patentable, and for inventions for which patents may be difficult to enforce, we rely on trade secret protection and confidentiality agreements to protect our interests. To this end, we require all employees, consultants, advisors and other contractors to enter into confidentiality agreements, which prohibit the disclosure of confidential information and, where applicable, require disclosure and assignment to us of the ideas, developments, discoveries and inventions important to our business.

In 2014, we acquired a novel PDT that utilizes safe visible light for activation, which we refer to as HyBryte™. The active ingredient in HyBryte™ is synthetic hypericin, a photosensitizer which is topically applied to skin lesions and then activated by fluorescent light 16 to 24 hours later. As part of the acquisition, we acquired a license agreement relating to the use of photo-activated hypericin, composition of matter patent for HyBryte™ (U.S. patent 8,629,302) and additional issued and pending applications, both in the U.S. and abroad. U.S. patent 8,629,302 is expected to expire in September 2030. In August 2018, we were granted a U.S. patent (No. 10,053,513) titled “Systems and Methods for Producing Synthetic Hypericin.” This newly issued patent, expected to expire in 2036, broadens the production around synthetic hypericin. Our proprietary formulation of synthetic hypericin also has been granted a European patent for the treatment of psoriasis, EP 2571507, and complements the method of treatment claims covered by the previously issued U.S. patent 6001882, Photoactivated hypericin and the use thereof. Further, on January 7, 2020, we also were granted a U.S. patent (No. 10,526,268) titled “Systems and Methods for Producing Synthetic Hypericin”, which further expanded protection for the composition of purified synthetic hypericin. This patent is also expected to expire in 2036. Patent protection is also pursued worldwide with similar patents and expiry dates.

In addition to issued and pending patents, we also have “Orphan Drug” designations for HyBryte™ in the U.S. and the EU for CTCL, for RiVax® in the U.S. and EU and for SGX945 in the U.S. Our Orphan Drug designations provide for seven years of post-approval marketing exclusivity in the U.S. and ten years exclusivity in Europe. We have pending patent applications for some indications that, if granted, may extend our anticipated marketing exclusivity beyond the U.S. seven year or EU ten year post-approval exclusivity provided by Orphan Drug legislation.

In 2013, we expanded our patent portfolio to include innate defense regulation through the acquisition of the novel drug technology, known as SGX94. By binding to the pivotal regulatory protein p62, also known as sequestosome-1, SGX94 regulates the innate immune system to reduce inflammation, eliminate infection and enhance healing. As part of the acquisition, we acquired all rights, including composition of matter patents for SGX94 as well as other analogs and crystal structures of SGX94 with its protein target p62, including U.S. patent 8,124,721 (expiring 2028), 9,416,157 (expiring 2028) and 8,791,061 (expiring 2029), both in the U.S. and abroad. SGX94 was developed pursuant to discoveries made by Professors B. Brett Finlay and Robert Hancock of University of British Columbia (“UBC”). We also have rights to the background technology patents 7,687,454 [expiring May 2026] and 11,311,598 [expiring 2034]). The U.S. Patent Office has also granted patents titled “Novel Peptides and Analogs for Use in the Treatment of Oral Mucositis.” The issued patents (U.S. patent numbers 9,850.279 and 10,253,068, both expiring in 2034) claim therapeutic use of dusquetide and related IDR analogs, and adds to composition of matter claims for dusquetide and related analogs that have been granted in the U.S. and worldwide.

ThermoVax® is the subject of U.S. patents 8,444,991 (expiring February 2030) and 8,808,710 (expiring March 2028) both issued on May 21, 2013 titled “Method of Preparing an Immunologically-Active Adjuvant-Bound Dried Vaccine Composition” and licensed to us by VitriVax, Inc. (“VitriVax”). ThermoVax® is also U.S. patent application number 15/694.023 filed September 17, 2017 titled “Thermostable Vaccine Compositions and Methods of Preparing Same” and jointly invented by the University of Colorado (“UC”) and us. The patent application and the corresponding foreign filings are pending or granted and they address the use of adjuvants in conjunction with vaccines that are formulated to resist thermal inactivation. The license agreement covers thermostable alum-adjuvanted vaccines for ricin toxin and EBOV. An additional patent, covering vaccine combinations such as ricin toxin and anthrax, was filed in 2015 and granted on May 21, 2019 in the U.S. (No. 10,293,041, titled “Multivalent Stable Vaccine Composition and Methods of Making Same”) and is expected to expire in 2035. A patent for unique, proprietary compositions and methods directed to combinations of glycoprotein antigens with nano-emulsion adjuvants comprising sucrose fatty acid esters prior to lyophilization was filed in 2020, granted in 2022 and

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expiring in 2040 (No. 11,433,129 titled “Compositions and Methods of Manufacturing Trivalent Filovirus Vaccines.”) Patent protection is also pursued worldwide with similar patents and expiry dates.

Additional vaccine thermostabilization patents specific for anti-viral vaccines, including filovirus and coronavirus have been filed but are not yet granted. If granted, expiry dates would range from 2040 to 2041. Patent protection is also pursued worldwide with similar patents and expiry dates.

HyBryte™ License Agreement

In September 2014, we acquired a worldwide exclusive license agreement with New York University and Yeda Research and Development Company Ltd. for the rights to a novel PDT that utilizes safe visible light for activation, which we refer to as HyBryte™. To maintain this license, we are obligated to pay $25,000 in annual license fees. In addition, we will pay the licensors: (a) a royalty amount equal to 3% of all net sales of HyBryte™ made directly by us and/or any affiliates; (b) a royalty amount equal to 2.5% of all net sales of HyBryte™ made by our sublicensees, subject to stated maximums and (c) 20% of all payments, not based on net sales, received by us from our sublicensees. This license may be terminated by either party upon notice of a material breach by the other party that is not cured within the applicable cure period. The exclusive license includes rights to several issued U.S. patents, including U.S. patent numbers 6,867,235 and 7,122,518, among other domestic and foreign patent applications. U.S. Patent numbers 6,867,235 and 7,122,518 expired in January 2020 and November 2023, respectively.

We acquired the license agreement for HyBryte™ and related intangible assets, including U.S. patent 8,629,302, properties and rights pursuant to an asset purchase agreement with Hy Biopharma Inc. (“Hy Biopharma”). As consideration for the assets acquired, we initially paid $275,000 in cash and issued 771 shares of common stock with a market value of $3,750,000, and in March 2020 we issued 8,151 shares of common stock at a value of $5,000,000 (based upon an effective per share price of $614.40) as a result of HyBryte™ demonstrating statistical significant treatment response in the Phase 3 clinical trial. Provided the final success-orientated milestone is attained, we will be required to make a payment of up to $5 million, if and when achieved, payable in our common stock.

SGX94 License Agreements

On December 18, 2012, we acquired a first in class drug technology, known as SGX94 (dusquetide), representing a novel approach to modulation of the innate immune system. SGX94 is an IDR that regulates the innate immune system to reduce inflammation, eliminate infection and enhance tissue healing by binding to the pivotal regulatory protein p62, also known as sequestosome-1. As part of the acquisition, we acquired all rights, including composition of matter patents, preclinical and Phase 1 clinical study datasets for SGX94. We also assumed a license agreement with UBC to advance the research and development of the SGX94 technology. The license agreement with UBC provides us with exclusive worldwide rights to manufacture, distribute, market sell and/or license or sublicense products derived or developed from this technology. Under the license agreement we are obligated to pay UBC (i) an annual license maintenance fee of CAD $1,000, and (ii) milestone payments which could reach up to CAD $1.2 million. This license agreement (a) will automatically terminate if we file, or become subject to an involuntary filing, for bankruptcy, and (b) may be terminated by UBC in the event of, among other things, our insolvency, dissolution, grant of a security interest in the technology licensed to us pursuant to the license agreement, or material breach of or failure to perform material obligations under the license agreement or other research agreements between us and UBC.

ThermoVax® License Agreement

On December 21, 2010, we executed a worldwide exclusive license agreement with the UC for ThermoVax®, which is the subject of U.S. patent number 8,444,991 issued on May 21, 2013 titled “Method of Preparing an Immunologically-Active Adjuvant-Bound Dried Vaccine Composition.” This patent and its corresponding foreign filings are licensed to us by the UC and they address the use of adjuvants in conjunction with vaccines that are formulated to resist thermal inactivation. U.S. Patent 8,444,991 is expected to expire in December 2031. The license agreement also covers thermostable vaccines for biodefense as well as other potential vaccine indications. In addition, we, in conjunction with UC, filed domestic and foreign patent applications claiming priority back to a provisional application filed on May 17, 2011 titled: “Thermostable Vaccine Compositions and Methods of Preparing Same.” In April 2018, the UC delivered a notice of termination of our license agreement based upon our failure to achieve one of the development milestones: initiation of the Phase 1 clinical trial of the heat stabilization technology by March 31, 2018. After negotiating with the UC, we and the UC agreed to extend the

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termination date to October 31, 2018 in order to allow us time to agree upon a potential agreement that would allow us to keep the rights to, and to continue to develop, the heat stabilization technology or a product candidate containing the heat stabilization technology in our field of use.

On October 31, 2018, in a series of related transactions, (a) we and the UC agreed to terminate the original license agreement, (b) the UC and VitriVax executed a worldwide exclusive license agreement for the heat stabilization technology for all fields of use, and (c) we and VitriVax executed a worldwide exclusive sublicense agreement, which was amended and restated in October 2020, for the heat stabilization technology for use in the fields of ricin and Ebola vaccines. We paid a $100,000 sublicense fee on the effective date of the sublicense agreement. Under the amended sublicense agreement to maintain the sublicense we are obliged to pay a minimum annual royalty of $20,000 until first commercial sale of a sublicensed product, upon which point, we will be required to pay an earned royalty of 2% of net sales subject to a minimum royalty of $50,000 each year. We are also required to pay royalties on any sub-sublicense income based on a declining percentage of all sub-sublicense income calculated within the contractual period until reaching a minimum of 15% after two years. In addition, we are required to pay VitriVax milestone fees of: (a) $25,000 upon initiation of a Phase 2 clinical trial of the sublicensed product, (b) $100,000 upon initiation of a Phase 3 clinical trial of the sublicensed product, (c) $100,000 upon regulatory approval of a sublicensed product, and (d) $1 million upon achieving $10 million in aggregate net sales of a sublicensed product in the U.S. or equivalent. To date none of these milestones have been met.

RiVax® License Agreement

In June 2003, we executed a worldwide exclusive option to license patent applications with UTSW for the nasal, pulmonary and oral uses of a non-toxic ricin vaccine. In June 2004, we entered into a license agreement with UTSW for the injectable rights to the ricin vaccine and, in October 2004, we negotiated the remaining oral rights to the ricin vaccine. To maintain this license, we are obligated to pay $50,000 in annual license fees. Through this license, we have rights to the issued patent number 7,175,848 titled “Ricin A chain mutants lacking enzymatic activity as vaccines to protect against aerosolized ricin.” This patent includes methods of use and composition claims for RiVax®. Patent 7,175,848 expired in September 2020.

CoVaccine HT™ License Agreement

In April 2020, we executed an agreement for the exclusive worldwide license of CoVaccine HT™, a novel vaccine adjuvant, from BTG, a division of Boston Scientific Corporation (NYSE: BSX), for the fields of SARS-CoV-2, the cause of COVID-19 and pandemic flu. The agreement was executed with Protherics Medicines Development, one of the companies that make up the BTG specialty pharmaceuticals business, which owns the CoVaccine HT™ intellectual property.

Research and Development Expenditures

We spent approximately $7.5 million and $5.2 million in the years ended December 31, 2025 and 2024, respectively, on research and development. The amounts we spent on research and development per product during the years ended December 31, 2025 and 2024 are set forth in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K.

Human Capital

We are committed to a work environment that is welcoming, inclusive and encouraging. To achieve our plans and goals, it is imperative that we attract and retain top talent. In order to do so, we aim to have a safe and encouraging workplace, with opportunities for our employees to grow and develop professionally, supported by strong compensation, benefits, and other incentives. In addition to competitive base salaries, we offer every full-time employee a cash target bonus, a comprehensive benefits package and equity compensation.

As of December 31, 2025, we employed a total of 14 persons, including 1 part-time employee and 13 full-time employees, four of whom are MDs/PhDs. In addition to our employees, we contract with third-parties for the conduct of certain clinical development, manufacturing, accounting and administrative activities. We anticipate increasing the number of our employees. We have no collective bargaining agreements with our employees, and none are represented by labor unions. We consider our relationships with our employees to be good.

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Available Investor Information

We file electronically with the Securities and Exchange Commission (“SEC”) our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) of 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). We make available through our website, free of charge, copies of these reports as soon as reasonably practicable after we electronically file or furnish them to the SEC. Our website is located at www.soligenix.com. You can also request copies of such documents by contacting the company at (609) 538-8200 or sending an email to info@soligenix.com.

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