Soligenix Receives Additional NIAID Funding to Advance Development of Heat Stable Ricin Vaccine

Awarded $2M to Advance Preclinical Efficacy Studies

PRINCETON, NJ June 21, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has exercised an option for the evaluation of RiVax® to fund additional animal efficacy studies. The overall objectives of the contract are to advance the development of Soligenix’s thermostabilization technology, ThermoVax®, in combination with the Company’s ricin toxin vaccine, RiVax®, as a medical countermeasure to prevent the effects of ricin exposure.

The exercised option for contract #HHSN272201400039C will provide Soligenix with approximately $2M in additional funding, bringing the total amount awarded to date under this contract to $18.7M.  If all contract options are exercised, the total award of up to $24.7 million will support the preclinical, manufacturing and clinical development activities necessary to advance heat stable RiVax® with the US Food and Drug Administration (FDA).

“The exercise of this option demonstrates the positive and productive collaboration between NIAID and the Soligenix team,” stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. “We look forward to accelerating our work with NIAID and engaging the FDA to advance the RiVax® program. We thank the NIAID team for its continued support and contribution to the Soligenix development program.”

About Ricin Toxin

Ricin toxin is a lethal plant-derived toxin and potential biological weapon because of its stability and high potency, and the fact it is readily extracted from by-products of castor oil production.  Ricin comes in many forms including powder, mist or pellet. Ricin can also be dissolved in water and other liquids. The US Centers for Disease Control and Prevention estimates that the lethal dose in humans is about the size of a grain of salt. Ricin toxin illness causes tissue necrosis and general organ failure leading to death within several days of exposure.  Ricin is especially toxic when inhaled. Ricin works by entering cells of the body and preventing the cells from making the proteins it needs. Without the proteins, cells die, which is eventually harmful to the entire body.

There are currently no effective treatments for ricin poisoning. The successful development of an effective vaccine against ricin toxin may act as a deterrent against the actual use of ricin as a biological weapon and could be used in rapid deployment scenarios in the event of a biological attack.

 About RiVax®

RiVax® is Soligenix’s proprietary heat stable recombinant subunit vaccine developed to protect against exposure to ricin toxin. With RiVax®, Soligenix is a world leader in the area of ricin toxin vaccine research.

RiVax® contains a genetically altered version of a Ricin Toxin A (RTA) chain containing two mutations that inactivate the toxicity of the ricin molecule. A Phase 1A clinical trial was conducted with a formulation of RiVax® that did not contain an adjuvant. This trial revealed dose dependent seroconversion as well as lack of toxicity of the molecule when administered intramuscularly to human volunteers. The adjuvant-free formulation of RiVax® induced toxin neutralizing antibodies that lasted up to 127 days after the third vaccination in several individuals.

To increase the longevity and magnitude of toxin neutralizing antibodies, RiVax® was subsequently formulated with an adjuvant of aluminum salts (known colloquially as Alum) for a Phase 1B clinical trial. Alum is an adjuvant that is used in many human vaccines, including most vaccines used in infants. 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®. In preclinical animal studies, the Alum formulation of RiVax® also induced higher titers and longer-lasting antibodies than the adjuvant-free vaccine. Vaccination with the thermostabilized Alum-adjuvanted RiVax® formulation in a large animal model provided 100% protection (p<0.0001) against acute exposure to aerosolized ricin, the most lethal route of exposure for ricin. The protected animals also had no signs of gross lung damage, a serious and enduring ramification with long-term consequences for survivors of ricin exposure. These results are described in a publication available here.

Heat stabilization of RiVax® is achieved with the Company’s proprietary ThermoVax® technology, designed to eliminate the cold-chain production, distribution and storage logistics required for most vaccines. The technology utilizes precise lyophilization of protein immunogens with conventional aluminum adjuvants in combination with secondary adjuvants for rapid onset of protective immunity with the fewest number of vaccinations. By employing ThermoVax® during the final formulation of RiVax®, the vaccine has demonstrated enhanced stability and the ability to withstand temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to one year.

The development of RiVax® has been sponsored through a series of grants from both NIAID, part of the National Institutes of Health, and the FDA, which were granted to Soligenix and to the University of Texas Southwestern (UTSW), where the vaccine protein originated. To date, Soligenix, Ellen Vitetta, PhD and her colleagues at UTSW have collectively received approximately $25 million in funding from NIAID for development of RiVax® and related vaccine technologies. RiVax® potentially would be added to the Strategic National Stockpile and dispensed in the event of a terrorist attack. RiVax® has received orphan drug designation from the FDA.

As a new chemical entity, an FDA approved RiVax® vaccine has the potential to qualify for a biodefense Priority Review Voucher (PRV), which allows the holder accelerated review of a drug application. Approved under the 21st Century Health Cures Act in late 2016, the biodefense PRV is awarded upon approval as a medical countermeasure when the active ingredient(s) have not been otherwise approved for use in any context. PRVs are transferable and can be sold, with sales in recent years varying from between $125 million to $350 million. When redeemed, PRVs entitle the user to an accelerated review period of six months, saving a median of seven months’ review time as calculated in 2009.  However, the 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 ($2.7 million in 2017).

 About ThermoVax®

 The ThermoVax® technology is designed to eliminate the cold chain production, distribution and storage logistics required for most vaccines. The technology utilizes precise lyophilization of protein immunogens with conventional aluminum adjuvants in combination with secondary adjuvants for rapid onset of protective immunity with the fewest number of vaccinations. Cold chain requirements add considerable cost to the production and storage of current conventional vaccines.  Elimination of the cold chain would also enhance the utility of these vaccines for emerging markets and for other applications requiring but lacking reliable cold chain capabilities.  For vaccines that are intended for long-term stockpiling, such as for use in biodefense or in pandemic situations, the utilization of ThermoVax® has the potential to facilitate easier storage and distribution of Strategic National Stockpile vaccines in emergency situations. The underlying ThermoVax® technology has been developed by Drs. John Carpenter and Theodore Randolph at the University of Colorado.

By employing ThermoVax® during the final formulation of RiVax®, the vaccine has demonstrated enhanced stability and the ability to withstand temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to one year. Similar stabilization at temperatures as high as 50 degrees Celsius for up to 3 months (maximum timepoint tested) have also been demonstrated with other antigens (e.g., human papillomavirus, Ebola and anthrax).

 About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to timing or success of the preclinical/clinical trials of RiVax®, that RiVax® will be approved for the PRV program or the amount for which a PRV for RiVax® can be sold.  These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Complete Efficacy and Long-Term Follow-Up Safety Results from SGX942 Phase 2 Oral Mucositis Clinical Trial to be Presented at the 2017 Multinational Association for Supportive Care in Cancer Conference

PRINCETON, NJ – June 19, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that it will be presenting final results from its SGX942 Phase 2 clinical trial in oral mucositis on June 23, 2017 at the Multinational Association for Supportive Care in Cancer (MASCC) conference taking place in Washington, DC from June 22 to 24, 2016.

SGX942 is the drug product using dusquetide, an Innate Defense Regulator, for the treatment of oral mucositis.  The trial entitled “A Phase 2, double-blind, randomized, placebo-controlled, dose-escalating, multicenter study of SGX942 for the attenuation of oral mucositis in patients being treated with concomitant chemoradiation for the treatment of squamous cell carcinoma of the head and neck”, was completed in late 2016 and was the first evaluation of dusquetide safety and efficacy in a sick patient population. In this clinical trial that enrolled 111 patients, SGX942 (1.5 mg/kg dusquetide) demonstrated a positive, clinically meaningful reduction in the median duration of severe oral mucositis, ranging from 50% in all patients, to 67% in patients receiving the most aggressive chemoradiation therapy (CRT) for treatment of their head and neck cancer (HNC).  In addition to the oral mucositis findings, decreases in the bacterial infection rate were observed with SGX942 treatment, along with an increased incidence of “complete response” of tumor (i.e., disappearance) at the one month follow-up visit and a reduction in opioid pain medication use. Recently published long-term follow-up data indicate that the tumor resolution was enduring and, moreover, that the mortality rate in the SGX942 1.5 mg/kg treatment group was lower (p=0.08) than the placebo group over the 12 months following completion of CRT. These data further support the safety and tolerability of SGX942 in this patient population. Potential ancillary benefits of utilizing SGX942 for the treatment of oral mucositis include the reduction of infection, the accelerated tumor resolution and the decreased mortality rate.

On the basis of these results, Soligenix has received US Food and Drug Administration (FDA) clearance for, and European Medicines Agency Scientific Advice on, a pivotal Phase 3 clinical trial, anticipated to be initiated in 2017.

Key data from the Phase 2 study will be presented.

Details of the Oral Presentation:

SGX942 is a Safe and Effective Treatment for Reducing the Duration of Severe Oral Mucositis in HNC Patients presented by Dr. Oreola Donini, Chief Scientific Officer and attended by Dr. Richard Straube, Chief Medical Officer on June 23, 2016 at 6:10 pm.  The abstract is available here.

About the MASCC Conference

“The Multinational Association of Supportive Care in Cancer (MASCC) is an international multidisciplinary organization dedicated to research, practice, and education in all aspects of supportive care for people with cancer, regardless of the stage of their disease.  Founded in 1990, MASCC now includes members from more than 60 countries and 5 continents.”  Details on the MASCC society can be found at http://www.mascc.org/.  The annual meeting is alternately held on various continents.  This year’s conference, held in conjunction with International Society of Oral Oncology in Washington DC, will feature plenary sessions on financial toxicity, precision medicine, and immunotherapy side effects.

About 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.  It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of mucositis, that mucositis affects approximately 500,000 people in the US 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 gastrointestinal 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 recently linked to the interaction of chemotherapy and/or radiation therapy with the innate defense system.  Bacterial infection of the ulcerative lesions is now regarded as a secondary consequence of dysregulated local inflammation triggered by therapy-induced cell death, rather than as the primary cause of the lesions.

It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of oral mucositis, that oral mucositis in HNC is a subpopulation of approximately 90,000 patients in the US, with a comparable number in Europe.  Oral mucositis almost always occurs in patients with HNC treated with chemoradiation therapy and is severe, causing inability to eat and/or drink, in >80% of patients. It is common (40-100% incidence) 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.

Oral mucositis in HNC remains an area of unmet medical need where there are currently no approved drug therapies.

About SGX942

Dusquetide (the active ingredient in SGX942) is an IDR, a new class of short, synthetic peptides.  It has a novel mechanism of action whereby it modulates the body’s reaction to both injury and infection towards an anti-inflammatory and an anti-infective response.  IDRs have no direct antibiotic activity but, by modulating the host’s innate immune system responses, increase survival after infections caused by a broad range of bacterial Gram-negative and Gram-positive pathogens.  It also accelerates resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma and chemo- and/or radiation therapy.  Preclinical efficacy and safety has been demonstrated in numerous animal disease models including mucositis, colitis, melioidosis, macrophage activation syndrome (MAS) and other bacterial infections.  Some of these preclinical findings have been published in an article entitled “A novel approach for emerging and antibiotic resistant infections: Innate defense regulators as an agnostic therapy,” available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.03.032.

SGX942 has demonstrated safety in a Phase 1 clinical study in 84 healthy human volunteers.  Recently, SGX942 had positive results in an exploratory Phase 2 clinical study in 111 patients with oral mucositis due to CRT for HNC.  Consistent with preclinical findings, SGX942 at a dose of 1.5 mg/kg demonstrated positive improvements in decreasing the duration of severe oral mucositis by 50% overall compared to the placebo group, from 18 days to 9 days (p=0.099).  In patients at the highest risk of developing severe oral mucositis (i.e., those receiving concomitant cisplatin chemotherapy of 80-100 mg/m2 every third week), the reduction in the duration of severe oral mucositis was even more significant at 67% when treated with SGX942 1.5 mg/kg, from 30 days to 10 days (p=0.04).  The p-values met the prospectively defined statistical threshold of p<0.1 in the study protocol.  Additional observations included an improved tumor response to CRT at the one month follow-up visit, as well as decreases in mortality and infection rate.  The study results are reviewed in “Dusquetide: A Novel Innate Defense Regulator Demonstrating a Significant and Consistent Reduction in the Duration of Oral Mucositis in Preclinical Data and a Randomized, Placebo-Controlled Phase 2 Clinical Study,” published online in the Journal of Biotechnology and available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.10.010.

Long-term (12 month) follow-up data further indicated the safety and tolerability of SGX942 treatment, with a sustained trend towards reduced mortality and increased tumor resolution in the 1.5 mg/kg SGX942 treatment group compared to the placebo group.  Opioid pain medication use was also seen to decrease over the course of CRT in the 1.5 mg/kg SGX942 treatment group at the point of highest oral mucositis risk, while it increased in the placebo group.  Detailed clinical results from the Phase 2 study, as well as a review of the pathogenesis of oral mucositis and the mechanism of action of SGX942, are discussed here. The long-term follow-up results from the Phase 2 study are reviewed in, “Dusquetide: Reduction in Oral Mucositis associated with Enduring Ancillary Benefits in Tumor Resolution and Decreased Mortality in Head and Neck Cancer Patients”, published online in Biotechnology Reports and available at the following link: https://doi.org/10.1016/j.btre.2017.05.002.

The Phase 2 oral mucositis clinical study was partially funded with a grant from the National Institute of Dental and Craniofacial Research Small Business Innovation Research grant #1R43 DE024032-01 (Soligenix, Inc.).

Drug products containing dusquetide have also received Fast Track Designations from the FDA for the treatment of oral mucositis as a result of radiation and/or chemotherapy treatment in HNC patients, and as an adjunctive therapy with other antibacterial drugs, for the treatment of melioidosis. Orphan Drug Designations for use of dusquetide in the treatment of MAS as well as for the treatment of acute radiation syndrome have also been granted. In addition, dusquetide has been granted Promising Innovative Medicine designation in the United Kingdom by the Medicines and Healthcare Products Regulatory Agency for the treatment of severe oral mucositis in HNC patients receiving CRT.

Dusquetide and related analogs have a strong intellectual property position, including composition of matter.  Dusquetide was developed pursuant to discoveries made by Professors B. Brett Finlay, PhD and Robert Hancock, PhD of the University of British Columbia, Canada.

About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of the Phase 3 clinical trial of SGX942 (dusquetide) as a treatment for oral mucositis in patients with head and neck cancer receiving chemoradiation therapy and the Phase 3 clinical trial of SGX301 (synthetic hypericin) for the treatment of cutaneous T-cell lymphoma. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Soligenix Announces Publication of its Phase 2 Long-Term Follow-Up Results of SGX942 for the Treatment of Oral Mucositis in Head and Neck Cancer Patients

At 12 Months SGX942 Found to be Safe and Well Tolerated with Multiple Potential Ancillary Benefits

 

PRINCETON, NJ – May 18, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that long-term follow-up data from its recent positive Phase 2 clinical trial, in which SGX942 (dusquetide) demonstrated a significant reduction in the median duration of severe oral mucositis in patients with head and neck cancer (HNC), have been published in the peer-reviewed journal Biotechnology Reports. These 12-month data further support the safety and tolerability of SGX942, with the 1.5 mg/kg treatment group demonstrating accelerated tumor resolution and a decreased mortality rate relative to the placebo group. The results were published online and are available here.

As a first-in-class innate defense regulator (IDR), dusquetide modulates the innate immune system, enhancing its tissue-healing and anti-infective mechanisms and decreasing the often deleterious inflammatory responses.  The pathogenesis of oral mucositis involves the dysregulation of the innate immune system.  In a randomized, double-blind, placebo-controlled Phase 2 clinical trial in 111 patients, SGX942 (1.5 mg/kg dusquetide) successfully reduced the median duration of severe oral mucositis when compared to placebo by 50% in all patients, and by 67% in patients receiving the most aggressive chemoradiation therapy (CRT) for treatment of their HNC.  In addition to the oral mucositis findings, decreases in the bacterial infection rate were observed with SGX942 treatment, along with an increased incidence of “complete response” of tumor (i.e., disappearance) at the one month follow-up visit and a reduction in opioid pain medication use.

Long-term follow-up data indicate that the tumor resolution was enduring and, moreover, that the mortality rate in the SGX942 1.5 mg/kg treatment group was lower (p=0.08) than the placebo group over the 12 months following completion of CRT. These data further support the safety and tolerability of SGX942 in this patient population. Potential ancillary benefits of utilizing SGX942 for the treatment of oral mucositis include the reduction of infection, the accelerated tumor resolution and the decreased mortality rate.

Soligenix recently announced that it has received US Food and Drug Administration (FDA) clearance to advance the pivotal Phase 3 clinical trial and released the protocol study design for SGX942, following the completion of the Phase 2 follow-up visits late last year. The Phase 3 study utilizes the patient population at highest risk of severe oral mucositis as identified in the Phase 2 study (i.e., those receiving the most aggressive CRT). While the drug effect was 67% in the Phase 2 study, a much more conservative estimate was utilized in planning the Phase 3 study, yielding a study size of approximately 190 subjects. SGX942 will be administered in conjunction with the CRT, as a treatment for oral mucositis.

“The long-term follow-up data further support the safety and tolerability of SGX942, consistent with the results from the previous Phase 1 study,” stated Richard Straube, MD, Senior Vice President and Chief Medical Officer of Soligenix. “The Phase 2 study also enabled a highly powered and efficient Phase 3 study to be designed, which will use duration of severe oral mucositis as the primary endpoint, while continuing to assess incidence of infection, tumor resolution status and survival as important safety endpoints. We look forward to starting the pivotal Phase 3 study this year.”

“The primary objective of the Phase 2 study was to demonstrate the safety and explore the efficacy of SGX942,” stated Oreola Donini, PhD, Senior Vice President and Chief Scientific Officer of Soligenix.  “The results from the follow-up evaluations indicate that SGX942 is safe and well tolerated and may have a number of additional benefits. The consistency between the clinical findings and the earlier nonclinical studies further demonstrates the applicability of dusquetide to a human clinical population in multiple indications, including reduction of infection. Accordingly, we will continue to explore expanding the IDR technology across additional indications, including antibiotic resistant and emerging infectious disease.”

The Phase 2 oral mucositis clinical study was partially funded with a grant from the National Institute of Dental and Craniofacial Research Small Business Innovation Research grant #1R43 DE024032-01 (Soligenix, Inc.).

About SGX942

Dusquetide (the active ingredient in SGX942) is an IDR, a new class of short, synthetic peptides.  It has a novel mechanism of action whereby it modulates the body’s reaction to both injury and infection towards an anti-inflammatory and an anti-infective response.  IDRs have no direct antibiotic activity but, by modulating the host’s innate immune system responses, increase survival after infections caused by a broad range of bacterial Gram-negative and Gram-positive pathogens.  It also accelerates resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma and chemo- and/or radiation therapy.  Preclinical efficacy and safety has been demonstrated in numerous animal disease models including mucositis, colitis, melioidosis, macrophage activation syndrome (MAS) and other bacterial infections.  Some of these preclinical findings have been published in an article entitled “A novel approach for emerging and antibiotic resistant infections: Innate defense regulators as an agnostic therapy,” available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.03.032.

SGX942 has demonstrated safety in a Phase 1 clinical study in 84 healthy human volunteers.  Recently, SGX942 had positive results in an exploratory Phase 2 clinical study in 111 patients with oral mucositis due to CRT for HNC.  Consistent with preclinical findings, SGX942 at a dose of 1.5 mg/kg demonstrated positive improvements in decreasing the duration of severe oral mucositis by 50% overall compared to the placebo group, from 18 days to 9 days (p=0.099).  In patients at the highest risk of developing severe oral mucositis (i.e., those receiving concomitant cisplatin chemotherapy of 80-100 mg/m2 every third week), the reduction in the duration of severe oral mucositis was even more significant at 67% when treated with SGX942 1.5 mg/kg, from 30 days to 10 days (p=0.04).  The p-values met the prospectively defined statistical threshold of p<0.1 in the study protocol.  Additional observations included an improved tumor response to CRT at the one month follow-up visit, as well as decreases in mortality and infection rate.  The study results are reviewed in “Dusquetide: A Novel Innate Defense Regulator Demonstrating a Significant and Consistent Reduction in the Duration of Oral Mucositis in Preclinical Data and a Randomized, Placebo-Controlled Phase 2 Clinical Study,” published online in the Journal of Biotechnology and available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.10.010.

Long-term (12 month) follow-up data further indicated the safety and tolerability of SGX942 treatment, with a sustained trend towards reduced mortality and increased tumor resolution in the 1.5 mg/kg SGX942 treatment group compared to the placebo group.  Opioid pain medication use was also seen to decrease over the course of CRT in the 1.5 mg/kg SGX942 treatment group at the point of highest oral mucositis risk, while it increased in the placebo group.  Detailed clinical results from the Phase 2 study, as well as a review of the pathogenesis of oral mucositis and the mechanism of action of SGX942, are discussed here. The long-term follow-up results from the Phase 2 study are reviewed in, “Dusquetide: Reduction in Oral Mucositis associated with Enduring Ancillary Benefits in Tumor Resolution and Decreased Mortality in Head and Neck Cancer Patients”, published online in Biotechnology Reports and available at the following link: https://doi.org/10.1016/j.btre.2017.05.002.

The Phase 2 oral mucositis clinical study was partially funded with a grant from the National Institute of Dental and Craniofacial Research Small Business Innovation Research grant #1R43 DE024032-01 (Soligenix, Inc.).

Drug products containing dusquetide have also received Fast Track Designations from the FDA for the treatment of oral mucositis as a result of radiation and/or chemotherapy treatment in HNC patients, and as an adjunctive therapy with other antibacterial drugs, for the treatment of melioidosis. Orphan Drug Designations for use of dusquetide in the treatment of MAS as well as for the treatment of acute radiation syndrome have also been granted. In addition, dusquetide has been granted Promising Innovative Medicine designation in the United Kingdom by the Medicines and Healthcare Products Regulatory Agency for the treatment of severe oral mucositis in HNC patients receiving CRT.

Dusquetide and related analogs have a strong intellectual property position, including composition of matter.  Dusquetide was developed pursuant to discoveries made by Professors B. Brett Finlay, PhD and Robert Hancock, PhD of the University of British Columbia, Canada.

About 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.  It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of mucositis, that mucositis affects approximately 500,000 people in the US 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 gastrointestinal 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 recently linked to the interaction of chemotherapy and/or radiation therapy with the innate defense system.  Bacterial infection of the ulcerative lesions is now regarded as a secondary consequence of dysregulated local inflammation triggered by therapy-induced cell death, rather than as the primary cause of the lesions.

It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of oral mucositis, that oral mucositis in HNC is a subpopulation of approximately 90,000 patients in the US, with a comparable number in Europe.  Oral mucositis almost always occurs in patients with HNC treated with CRT and is severe, causing inability to eat and/or drink, in >80% of patients. It is common (40-100% incidence) 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.

Oral mucositis in HNC remains an area of unmet medical need where there are currently no approved drug therapies.

About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of the Phase 3 clinical trial of SGX942 (dusquetide) as a treatment for oral mucositis in patients with head and neck cancer receiving chemoradiation therapy and the Phase 3 clinical trial of SGX301 (synthetic hypericin) for the treatment of cutaneous T-cell lymphoma. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Soligenix Announces Recent Accomplishments And First Quarter 2017 Financial Results

PRINCETON, NJ – May 11, 2017 Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today its recent accomplishments and financial results for the first quarter ended March 31, 2017.

Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix stated, “We are  pleased to have FDA protocol clearance of a pivotal Phase 3 clinical trial of SGX942 (dusquetide) for the treatment of oral mucositis in patients with head and neck cancer.  Additionally, we are encouraged by the response received from the EMA that this same Phase 3 clinical study, if positive, would also be sufficient to establish the efficacy and safety of SGX942 in support of potential marketing authorization in Europe. We believe that the positive Scientific Advice outcome represents a significant step forward in our oral mucositis development program and has the potential to accelerate the registration timetable in Europe.  Given the current timeline, we anticipate initiating this pivotal Phase 3 clinical trial in the second quarter  of 2017.”

Dr. Schaber continued, “We also continue to actively enroll patients in our pivotal Phase 3 study in cutaneous T-cell lymphoma with SGX301 (synthetic hypericin), in which we expect data by the end of the year.  In our Vaccines/BioDefense business segment, we are pleased with the efficacy results from our heat stable ricin vaccine, RiVax®, which has demonstrated significantly enhanced thermostability and 100% protection in preclinical ricin aerosol challenge models.”

Soligenix Recent Accomplishments:

  • On February 22, 2017, the Company announced that its proprietary formulation of synthetic hypericin had been granted a European patent for the treatment of psoriasis. The issued patent, EP 2571507, Formulations and methods of treatment of skin conditions, complements the method of treatment claims covered by the previously issued US patent 6001882, Photoactivated hypericin and the use thereof.
  • On February 2, 2017, the Company announced that SGX301 (synthetic hypericin) had been granted Promising Innovative Medicine (PIM) designation in the United Kingdom by the Medicines and Healthcare Products Regulatory Agency for the treatment of cutaneous T-cell lymphoma. The PIM designation is the first step towards inclusion in the Early Access to Medicines Scheme which offers severely ill patients with life-threatening and seriously debilitating conditions the lifeline of trying ground-breaking new medicines much earlier than they would normally be accessible.
  • On January 5, 2017, the Company announced it had received positive Scientific Advice from the European Medicines Agency (EMA) for the development of SGX942 (dusquetide) as a treatment for oral mucositis in patients with head and neck cancer receiving chemoradiation therapy. The Scientific Advice from the EMA indicates that a single, double-blind, placebo-controlled, multinational, Phase 3 pivotal study (IDR-OM-02), if successful, in conjunction with the Phase 2 dose-ranging study IDR-OM-01, is generally considered sufficient to support a marketing authorization application to the EMA for potential licensure in Europe.
  • On January 3, 2017, the Company announced it had extended its development agreement with Emergent BioSolutions to implement a commercially viable, scalable production technology for the RiVax® drug substance antigen. The RiVax® project is being developed with up to a $26 million contract award from National Institute of Allergy and Infectious Diseases (NIAID).

Financial Results – First Quarter Ended March 31, 2017

Soligenix’s revenues for the quarter ended March 31, 2017 were $1.3 million as compared to $2.6 million for the prior year. Revenues included contracts with NIAID and Biomedical Advanced Research and Development Authority (BARDA) in support of the advanced development of the Company’s thermostabilization technology, ThermoVax®, combined with its ricin toxin vaccine RiVax®, as a medical countermeasure to prevent the effects of ricin exposure and OrbeShield® (oral beclomethasone 17,21 dipropionate) in the treatment of gastrointestinal acute radiation syndrome.

Soligenix’s basic net loss was $1.7 million, or $(0.32) per share, for the quarter ended March 31, 2017 as compared to $1.1 million, or $(0.37) per share for the same quarter of the prior year. Included in the net loss for the quarter ended March 31, 2016 is non-cash other income of $0.8 million. This non-cash other income reflects the change in fair value of the liability related to warrants issued in the Company’s June 25, 2013 registered public offering and is not included in other income for the quarter ended March 31, 2017, as the warrant liability was reclassified to equity during the year ended December 31, 2016.

Research and development expenses were $1.2 million as compared to $1.4 million for the quarters ended March 31, 2017 and 2016, respectively. The decrease is primarily a result of the completion of the Phase 2 trial of SGX942 for the treatment of oral mucositis in head and neck cancer patients during the first quarter of 2017 and the trial initiation costs incurred for the Phase 3 trial of SGX301 during the first quarter of 2016.

General and administrative expenses were $0.8 million as compared to $0.9 million for the quarters ended March 31, 2017 and 2016, respectively. This decrease is the result of a decrease in professional fees.

As of March 31, 2017, the Company’s cash position was $7.1 million.

About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of the Phase 3 clinical trial of SGX942 (dusquetide) as a treatment for oral mucositis in patients with head and neck cancer receiving chemoradiation therapy and the Phase 3 clinical trial of SGX301 (synthetic hypericin) for the treatment of cutaneous T-cell lymphoma. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Soligenix Receives Japanese Patent for ThermoVax® Vaccine Heat Stabilization Platform Technology

Patent describes application of ThermoVax® with RiVax®

PRINCETON, NJ – May 9, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that it has been granted a Japanese patent (number 6110845) further extending protection around ThermoVax® including coverage of the Company’s ricin toxin vaccine candidate, RiVax®. ThermoVax® is a proprietary vaccine heat stabilization platform technology and the patent, entitled “Thermostable vaccine compositions and methods of preparing same,” is also being pursued in other major markets worldwide, such as China, Europe, and the US.

The issued patent is complementary to previous patents, including US patents 8,444,991 granted on May 21, 2013 and 8,808,710 granted on August 19, 2014, that include claims for methods of making stabilized vaccines and their attendant compositions.  In this new patent, the main claims cover formulations of Soligenix’s proprietary thermostabilized ricin toxin vaccine, RiVax®. The thermostable formulation of RiVax® has been shown to be stable for at least 12 months at temperatures up to 40 degrees Celsius (104 degrees Fahrenheit) and to provide 100% protection to non-human primates exposed to aerosol ricin challenge.

Recent developments in the RiVax® program have also described immune correlates of protection for the ricin toxin vaccine, which are important to facilitating potential approval of thermostabilized RiVax® via the US Food and Drug Administration (FDA) “Animal Rule”. As a biodefense vaccine, RiVax® also has the potential to qualify for a priority review voucher (PRV) upon FDA approval. Recent PRVs have sold for as much $350 million.

“ThermoVax® has successfully demonstrated that it can thermostabilize a number of different alum-adjuvanted protein antigens, including antigens for ricin, anthrax, human papillomavirus and Ebola,” stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. “The RiVax® program continues to progress towards potential approval under the Animal Rule, and as our most advanced product candidate using the ThermoVax® technology, it also provides positive proof-of-concept for use of this proprietary heat stabilization platform with other development and commercial vaccines. While we advance RiVax® with the support of NIAID contract funding, we also look forward to potentially applying the ThermoVax® technology to other vaccine candidates in the future.”

 About ThermoVax®

 The ThermoVax® technology is designed to eliminate the cold chain production, distribution and storage logistics required for most vaccines. The technology utilizes precise lyophilization of protein immunogens with conventional aluminum adjuvants in combination with secondary adjuvants for rapid onset of protective immunity with the fewest number of vaccinations. Cold chain requirements add considerable cost to the production and storage of current conventional vaccines.  Elimination of the cold chain would also enhance the utility of these vaccines for emerging markets and for other applications requiring but lacking reliable cold chain capabilities.  For vaccines that are intended for long-term stockpiling, such as for use in biodefense or in pandemic situations, the utilization of ThermoVax® has the potential to facilitate easier storage and distribution of Strategic National Stockpile vaccines in emergency situations. The underlying ThermoVax® technology has been developed by Drs. John Carpenter and Theodore Randolph at the University of Colorado.

By employing ThermoVax® during the final formulation of RiVax®, the vaccine has demonstrated enhanced stability and the ability to withstand temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to one year. Similar stabilization at temperatures as high as 50 degrees Celsius for up to 3 months (maximum timepoint tested) have also been demonstrated with other antigens (e.g., human papillomavirus, Ebola and anthrax).

About RiVax®

RiVax® is Soligenix’s proprietary heat stable recombinant subunit vaccine developed to protect against exposure to ricin toxin. With RiVax®, Soligenix is a world leader in the area of ricin toxin vaccine research.

RiVax® contains a genetically altered version of a Ricin Toxin A (RTA) chain containing two mutations that inactivate the toxicity of the ricin molecule. A Phase 1A clinical trial was conducted with a formulation of RiVax® that did not contain an adjuvant. This trial revealed dose dependent seroconversion as well as lack of toxicity of the molecule when administered intramuscularly to human volunteers. The adjuvant-free formulation of RiVax® induced toxin neutralizing antibodies that lasted up to 127 days after the third vaccination in several individuals.

To increase the longevity and magnitude of toxin neutralizing antibodies, RiVax® was subsequently formulated with an adjuvant of aluminum salts (known colloquially as Alum) for a Phase 1B clinical trial. Alum is an adjuvant that is used in many human vaccines, including most vaccines used in infants. 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®. In preclinical animal studies, the Alum formulation of RiVax® also induced higher titers and longer-lasting antibodies than the adjuvant-free vaccine. Vaccination with the thermostabilized Alum-adjuvanted RiVax® formulation in a large animal model provided 100% protection (p<0.0001) against acute exposure to aerosolized ricin, the most lethal route of exposure for ricin. The protected animals also had no signs of gross lung damage, a serious and enduring ramification with long-term consequences for survivors of ricin exposure. These results are described in a publication available here.

The development of RiVax® has been sponsored through a series of grants from both NIAID, part of the National Institutes of Health, and the FDA, which were granted to Soligenix and to the University of Texas Southwestern (UTSW) where the vaccine protein originated. To date, Soligenix, Dr. Ellen Vitetta and her colleagues at UTSW have collectively received approximately $25 million in funding from NIAID for development of RiVax® and related vaccine technologies. Currently, Soligenix is developing RiVax® under NIAID contract #HHSN272201400039C, worth up to $26 million, assuming all options are exercised.   RiVax® has received orphan drug designation from the FDA.

RiVax® potentially would be added to the Strategic National Stockpile and dispensed in the event of a terrorist attack. As a new chemical entity, an FDA approved RiVax® vaccine also has the potential to qualify for a biodefense PRV, which allows the holder accelerated review of a drug application. Approved under the 21st Century Health Cures Act in late 2016, the biodefense PRV is awarded upon approval as a medical countermeasure when the active ingredient(s) have not been otherwise approved for use in any context. PRVs are transferable and can be sold, with sales in recent years varying from between $125 million to $350 million.

 About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to timing or success of the preclinical/clinical trials of RiVax®, that RiVax® will be approved for the PRV program or the amount for which a PRV for  RiVax® can be sold.  These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Soligenix Receives FDA Protocol Clearance of Pivotal Phase 3 Clinical Trial of SGX942 for the Treatment of Oral Mucositis in Head and Neck Cancer Patients

Trial Targeted to Begin in Second Quarter of 2017

PRINCETON, NJ – May 3, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that it has received US Food and Drug Administration (FDA) clearance to advance a pivotal Phase 3 clinical trial evaluating SGX942 (dusquetide) for the treatment of oral mucositis in head and neck cancer (HNC) patients being treated with chemoradiation (CRT).  Soligenix plans to begin this study in the second quarter of 2017.

Based on positive Phase 2 results (Study IDR-OM-01), the upcoming pivotal Phase 3 clinical trial (Study IDR-OM-02) will be a highly powered, double-blind, randomized, placebo-controlled, multinational trial that will seek to enroll approximately 190 subjects with squamous cell carcinoma of the oral cavity and oropharynx who are 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 will be randomized to receive either 1.5 mg/kg SGX942 or placebo given twice a week during and for 2 weeks following completion of CRT. The primary endpoint for the study will be the median duration of severe oral mucositis, which will be assessed by oral examination at each treatment visit and then through 6 weeks following completion of CRT. Oral mucositis will be evaluated using the WHO Grading system. Severe oral mucositis is defined as a WHO Grade of ≥3. Subjects will be followed for an additional 12 months after the completion of treatment.

The study design incorporates feedback from the FDA as well as from the European Medicines Agency (EMA) via the Scientific Advice process.  The Scientific Advice from the EMA indicates that a single, double-blind, placebo-controlled, multinational, Phase 3 pivotal study, if successful, in conjunction with results from the Phase 2 dose-ranging study, generally will be considered sufficient to support a marketing authorization application (MAA) for potential licensure in Europe.

“We are pleased to have a pivotal Phase 3 study design that incorporates feedback from both the FDA and EMA, and that has the potential to support marketing approval in both the US and the European Union,” stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix.  “Study initiation later this year will represent a significant step forward in our oral mucositis development program.  We look forward to advancing this pivotal trial in an effort to address the significant unmet medical need that currently exists in this patient population.”

About SGX942

Dusquetide (the active ingredient in SGX942) is an innate defense regulator (IDR), a new class of short, synthetic peptides.  It has a novel mechanism of action whereby it modulates the body’s reaction to both injury and infection towards an anti-inflammatory and an anti-infective response.  IDRs have no direct antibiotic activity but, by modulating the host’s innate immune system responses, increase survival after infections caused by a broad range of bacterial Gram-negative and Gram-positive pathogens.  It also accelerates resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma and chemo- and/or radiation therapy.  Preclinical efficacy and safety has been demonstrated in numerous animal disease models including mucositis, colitis, melioidosis, macrophage activation syndrome (MAS) and other bacterial infections.  Some of these preclinical findings have been published in an article entitled “A novel approach for emerging and antibiotic resistant infections: Innate defense regulators as an agnostic therapy”, available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.03.032.

SGX942 has demonstrated safety in a Phase 1 clinical study in 84 healthy human volunteers.  Recently, SGX942 had positive results in an exploratory Phase 2 clinical study in 111 patients with oral mucositis due to CRT therapy for HNC.  Consistent with preclinical findings, SGX942 at a dose of 1.5 mg/kg demonstrated positive improvements in decreasing the duration of severe oral mucositis by 50% overall compared to the placebo group, from 18 days to 9 days (p=0.099).  In patients at the highest risk of developing severe oral mucositis (i.e., those receiving concomitant cisplatin chemotherapy of 80-100 mg/m2 every third week), the reduction in the duration of severe oral mucositis was even more significant at 67% when treated with SGX942 1.5 mg/kg, from 30 days to 10 days (p=0.04).  The p-values met the prospectively defined statistical threshold of p<0.1 in the study protocol.  Additional observations included an improved tumor response to CRT therapy at the one month follow-up visit, as well as decreases in mortality and infection rate.  The study results are reviewed in “Dusquetide: A Novel Innate Defense Regulator Demonstrating a Significant and Consistent Reduction in the Duration of Oral Mucositis in Preclinical Data and a Randomized, Placebo-Controlled Phase 2 Clinical Study,” published online in the Journal of Biotechnology and available at the following link: http://dx.doi.org/10.1016/j.jbiotec.2016.10.010.

Long-term (12 month) follow-up data further indicated the safety and tolerability of SGX942 treatment, with a sustained trend towards reduced mortality and increased tumor resolution in the 1.5 mg/kg SGX942 treatment group compared to the placebo group.  Opioid pain medication use was also seen to decrease over the course of CRT in the 1.5 mg/kg SGX942 treatment group at the point of highest oral mucositis risk, while it increased in the placebo group.  Detailed clinical results from the Phase 2 study, as well as a review of the pathogenesis of oral mucositis and the mechanism of action of SGX942, are discussed here.

The Phase 2 oral mucositis clinical study was partially funded with a grant from the National Institute of Dental and Craniofacial Research Small Business Innovation Research grant #1R43 DE024032-01 (Soligenix, Inc).

Dusquetide and related analogs have a strong intellectual property position, including composition of matter.  Dusquetide was developed pursuant to discoveries made by Professors B. Brett Finlay, PhD and Robert Hancock, PhD of the University of British Columbia, Canada.

Drug products containing dusquetide have also received Fast Track Designations from the FDA for the treatment of oral mucositis as a result of radiation and/or chemotherapy treatment in HNC patients, and as an adjunctive therapy with other antibacterial drugs, for the treatment of melioidosis. Orphan Drug Designations for use of dusquetide in the treatment of MAS as well as for the treatment of acute radiation syndrome have also been granted. In additon, dusquetide has been granted Promising Innovative Medicine (PIM) designation in the United Kingdom by the Medicines and Healthcare Products Regulatory Agency (MHRA) for the treatment of severe oral mucositis in HNC patients receiving CRT.

About 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.  It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of mucositis, that mucositis affects approximately 500,000 people in the US 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 gastrointestinal 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 recently linked to the interaction of chemotherapy and/or radiation therapy with the innate defense system.  Bacterial infection of the ulcerative lesions is now regarded as a secondary consequence of dysregulated local inflammation triggered by therapy-induced cell death, rather than as the primary cause of the lesions.

It is estimated, based upon review of historic published studies and reports and an interpolation of data on the incidence of oral mucositis, that oral mucositis in HNC is a subpopulation of approximately 90,000 patients in the US, with a comparable number in Europe.  Oral mucositis almost always occurs in patients with HNC treated with chemoradiation therapy and is severe, causing inability to eat and/or drink, in >80% of patients. It is common (40-100% incidence) 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.

Oral mucositis in HNC remains an area of unmet medical need where there are currently no approved drug therapies.

About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax®, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to the timing or success of the Phase 3 clinical trial of SGX942 (dusquetide) as a treatment for oral mucositis in patients with head and neck cancer receiving chemoradiation therapy and the Phase 3 clinical trial of SGX301 (synthetic hypericin) for the treatment of cutaneous T-cell lymphoma. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.

Efficacy Results from Soligenix’s Ricin Toxin Vaccine Program to be Presented at the 20th Annual Conference on Vaccine Research

PRINCETON, NJ April 19, 2017 – Soligenix, Inc. (Nasdaq: SNGX) (Soligenix or the Company), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today that results from its ricin toxin vaccine (RiVax™) development program will be presented at the 20th Annual Conference on Vaccine Research, being held April 24-26 in Bethesda, Md.

Serum Antibody Profiling following Vaccination Reveals a Correlate of Immunity to Ricin Toxin” will be presented by Jennifer Yates, Ph.D., New York State Department of Health, Wadsworth Center and attended by Oreola Donini, Ph.D., Chief Scientific Officer of Soligenix, on April 25 at 2:15 p.m. Eastern time.

RiVax™ is the Company’s proprietary vaccine candidate for the prevention of exposure to ricin toxin that utilizes a unique antigen that is completely devoid of the toxic activity of ricin. When formulated with ThermoVax®, Soligenix’s proprietary vaccine heat stabilization technology, RiVax™ has demonstrated significantly enhanced thermostability and 100% protection in preclinical ricin aerosol challenge models.

In collaboration with the New York State Department of Health and the laboratory of Nicholas Mantis, Ph.D., Soligenix has been investigating immune correlates of protection in sera of animals vaccinated with RiVax™. The findings demonstrate that: 1) the ThermoVax® thermostabilization process significantly enhances the stability of the RiVax™ antigen; 2) degradation in the antigen can be measured with specific monoclonal antibodies; and 3) these same monoclonal antibodies can be used to probe the immune profile of vaccinated mice and primates and predict their survival to subsequent ricin exposure challenge.

These findings are expected to facilitate the potential approval of the RiVax™ product under the U.S. Food and Drug Administration (FDA) “Animal Rule” and represent a significant step forward in the understanding of ricin toxin immunology.  This work was funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, via Contract #HHSN272201400039C.

About the Annual Conference on Vaccine Research

 In its 20th year, the Annual Conference on Vaccine Research is offered by the National Foundation of Infectious Diseases and brings together experts from around the world, including healthcare professionals, researchers, public health experts and industry. The 2017 conference includes a diverse range of topics including therapeutic vaccines and the use of novel technologies to fight emerging infectious diseases. Details regarding the annual conference can be found here.

About Ricin Toxin

Ricin toxin is a lethal plant-derived toxin and potential biological weapon because of its stability and high potency, and the fact it is readily extracted from by-products of castor oil production.  Ricin comes in many forms including powder, mist or pellet. Ricin can also be dissolved in water and other liquids.  The U.S. Centers for Disease Control and Prevention (CDC) estimates the lethal dose in humans is about the size of a grain of salt.  Ricin toxin illness causes tissue necrosis and general organ failure leading to death within several days of exposure.  Ricin is especially toxic when inhaled.  Ricin works by entering cells of the body and preventing the cells from making the proteins it needs.  Without the proteins, cells die, which is eventually harmful to the entire body.

There are currently no effective treatments for ricin poisoning.  The successful development of an effective vaccine against ricin toxin may act as a deterrent against the actual use of ricin as a biological weapon and could be used in rapid deployment scenarios in the event of a biological attack.

 About RiVax™

RiVax™ is Soligenix’s proprietary heat stable recombinant subunit vaccine developed to protect against exposure to ricin toxin. With RiVax™, Soligenix is a world leader in the area of ricin toxin vaccine research.

RiVax™ contains a genetically altered version of a Ricin Toxin A (RTA) chain containing two mutations that inactivate the toxicity of the ricin molecule. A Phase 1A clinical trial was conducted with a formulation of RiVax™ that did not contain an adjuvant. This trial revealed dose dependent seroconversion as well as lack of toxicity of the molecule when administered intramuscularly to human volunteers. The adjuvant-free formulation of RiVax™ induced toxin neutralizing antibodies that lasted up to 127 days after the third vaccination in several individuals.

To increase the longevity and magnitude of toxin neutralizing antibodies, RiVax™ was subsequently formulated with an adjuvant of aluminum salts (known colloquially as Alum) for a Phase 1B clinical trial. Alum is an adjuvant that is used in many human vaccines, including most vaccines used in infants. 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™. In preclinical animal studies, the Alum formulation of RiVax™ also induced higher titers and longer-lasting antibodies than the adjuvant-free vaccine. Vaccination with the thermostabilized Alum-adjuvanted RiVax™ formulation in a large animal model provided 100% protection (p<0.0001) against acute exposure to aerosolized ricin, the most lethal route of exposure for ricin. The protected animals also had no signs of gross lung damage, a serious and enduring ramification with long-term consequences for survivors of ricin exposure.

Heat stabilization of RiVax™ is achieved with the Company’s proprietary ThermoVax® technology, designed to eliminate the cold-chain production, distribution and storage logistics required for most vaccines. The technology utilizes precise lyophilization of protein immunogens with conventional aluminum adjuvants in combination with secondary adjuvants for rapid onset of protective immunity with the fewest number of vaccinations. By employing ThermoVax® during the final formulation of RiVax™, the vaccine has demonstrated enhanced stability and the ability to withstand temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to one year.

The development of RiVax™ has been sponsored through a series of grants from both the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and the FDA, which were granted to Soligenix and to the University of Texas Southwestern (UTSW) where the vaccine protein originated. To date, Soligenix, Ellen Vitetta, Ph.D. and her colleagues at UTSW have collectively received approximately $25 million in funding from NIAID for development of RiVax™ and related vaccine technologies. RiVax™ potentially would be added to the Strategic National Stockpile and dispensed in the event of a terrorist attack. RiVax™ has received orphan drug designation from the FDA.

As a new chemical entity, an FDA approved RiVax™ vaccine has the potential to qualify for a biodefense Priority Review Voucher, which allows the holder accelerated review of a drug application. Approved under the 21st Century Health Cures Act in late 2016, the biodefense PRV is awarded upon approval as a medical countermeasure when the active ingredient(s) have not been otherwise approved for use in any context. PRVs are transferable and can be sold, with sales in recent years varying from between $125 million to $350 million.

 About Soligenix, Inc.

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need. Our BioTherapeutics business segment is developing SGX301 as a novel photodynamic therapy utilizing safe visible light for the treatment of cutaneous T-cell lymphoma, our first-in-class innate defense regulator (IDR) technology, dusquetide (SGX942) for the treatment of oral mucositis in head and neck cancer, and proprietary formulations of oral beclomethasone 17,21-dipropionate (BDP) for the prevention/treatment of gastrointestinal (GI) disorders characterized by severe inflammation including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201).

Our Vaccines/BioDefense business segment includes active development programs for RiVax™, our ricin toxin vaccine candidate, OrbeShield®, our GI acute radiation syndrome therapeutic candidate and SGX943, our therapeutic candidate for antibiotic resistant and emerging infectious disease. 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) and the Biomedical Advanced Research and Development Authority (BARDA).

For further information regarding Soligenix, Inc., please visit the Company’s website at www.soligenix.com.

This press release may contain forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “believes,” “hopes,” “intends,” “plans,” “expects,” “goal,” “may,” “suggest,” “will,” “potential,” or similar expressions, are forward-looking statements.  These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements.  Soligenix cannot assure you that it will be able to successfully develop, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing therapeutics and vaccines against bioterror threats, conducting preclinical and clinical trials of therapeutics and vaccines, obtaining regulatory approvals and manufacturing therapeutics and vaccines, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further funding to support product development and commercialization efforts, including grants and awards, maintain its existing grants which are subject to performance requirements, enter into any biodefense procurement contracts with the U.S. Government or other countries, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, or that the U.S. Congress may not pass any legislation that would provide additional funding for the Project BioShield program. In addition, there can be no assurance as to timing or success of the preclinical/clinical trials of RiVax™, that RiVax™ will be approved for the PRV program or the amount for which a PRV for  RiVax™ can be sold.  These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K.  Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.