Driving Towards Key Inflection Points

- Driving Towards Key Inflection Points

Two Pivotal Phase 3 Clinical Trials

provides 2017 highlights and 2018 development program guidance

NJ - January 25, 2018 - 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, today

issued an update letter from its President and Chief Executive Officer, Dr. Christopher J. Schaber. The content of this letter

Friends and Shareholders,

that we have concluded 2017, I wanted to take this opportunity to provide a summary of our progress and highlight our accomplishments

made during the year, as well as to provide some further guidance on our development programs as we begin 2018.

focus this coming year remains, first and foremost, the quality execution of our two pivotal Phase 3 clinical trials, including

SGX942 (dusquetide) for the treatment of oral mucositis in head and neck cancer and SGX301 (synthetic hypericin) for the treatment

of cutaneous T-cell lymphoma (CTCL). In addition, we are continuing to advance development of our heat stable ricin toxin vaccine

(RiVax ) with the financial support of the National Institute of Allergy and Infectious Diseases (NIAID), part

of the National Institutes of Health (NIH), while we also continue to actively pursue non-dilutive funding to support our rare

the year, we were awarded in excess of $8.6 million in non-dilutive funding from various government sources across our entire

biodefense and biotherapeutics pipeline in order to advance multiple development programs, which support we greatly appreciate.

As part of this funding, we received approval for a tax credit from the New Jersey Economic Development Authority's New

Jersey Technology Business Tax Certificate Transfer program and received approximately $417,000 in net proceeds from the transfer

the third quarter, we received two Small Business Innovative Research (SBIR) grant awards totaling approximately $3 million over

two years by the NIH National Cancer Institute (NCI) and the National Institute of Dental and Craniofacial Research (NIDCR) for

two of our biotherapeutics development programs. The award from the NCI is to support the conduct of our ongoing pivotal Phase

3 trial of SGX301 as a treatment for CTCL, and the award from the NIDCR is to support the conduct of our ongoing pivotal Phase

3 trial of SGX942 as a treatment for severe oral mucositis in patients with head and neck cancer receiving chemoradiation therapy

the year, we also received over $5 million of non-dilutive funding in our biodefense business segment. NIAID exercised a $2.5

million option to fund good manufacturing practice compliant RiVax bulk drug substance and finished drug product

manufacturing and a $2 million option to fund additional RiVax animal efficacy studies. The overall objective

of the contract, totaling up to $24.7 million over six years, is to advance the development of our thermostabilization technology,

ThermoVax , in combination with RiVax , our ricin toxin vaccine, as a countermeasure to prevent

the effects of ricin exposure. Additionally, we were awarded funding of approximately $700,000 over five years, as collaborators

in a NIAID Research Project grant awarded to the University of Hawai'i at Manoa for the development of a trivalent thermostabilized

addition to the non-dilutive funding received, we completed a registered direct offering of 1,575,500 shares of common stock and

a concurrent private placement of 982,000 shares of common stock at an above the market purchase price of $2.00 per share. Our

gross proceeds from these offerings were $5,115,000 before deducting offering expenses. The lead investors in the financing included

Knoll Capital Management, LP and ACT Capital Management, LLLP, two fundamental life science investors, and two of our largest

existing shareholders.

begin 2018 with approximately $8 million in cash, not including our non-dilutive NIH funding.

the year, we made good progress in advancing our clinical development programs. We continue to actively enroll patients in our

pivotal Phase 3 study in CTCL with SGX301 (synthetic hypericin) and are encouraged by this development program as a potential

front line treatment where there is currently an unmet medical need. This trial, referred to as the "FLASH" study

(Fluorescent Light Activated Synthetic Hypericin), aims to evaluate the response to SGX301

as a skin directed therapy to treat early stage CTCL. SGX301 has received Orphan Drug designation as well as Fast Track designation

from the United States (US) Food and Drug Administration (FDA). Additionally, SGX301 was granted Orphan Drug designation from

the European Medicines Agency (EMA) and Promising Innovative Medicine (PIM) designation from the Medicines and Healthcare Products

Regulatory Agency (MHRA) in the United Kingdom (UK).

thirty CTCL centers across the US are participating in this pivotal trial. Although the trial begins with a double-blind, placebo-controlled

portion (referred to as Cycle 1), all participants in the trial eventually receive active study drug (referred to as Cycle 2)

and an optional portion of the trial is available to them to continue with SGX301 treatment (referred to as Cycle 3). We remain

encouraged by the response to this trial and by the majority of patients that have elected to continue into the optional open-label

portion of the study. We continue to work closely with the Cutaneous Lymphoma Foundation, as well as the National Organization

for Rare Disorders. As CTCL is a chronic disease that patients can potentially live with for many years, if closely managed, study

enrollment can ebb and flow with the summer vacation and winter holiday seasons, as some patients tend to not start new treatments

that may interfere with important family events; therefore, we continue to take a conservative approach to estimating study completion

and availability of top-line data. As a result, we have adjusted our trial guidance, with the prospectively defined, blinded interim

analysis taking place in the second half of 2018 and top-line final study results potentially moving into the first half of 2019.

Rest assured, we take development timelines very seriously. To this end, quality enrollment and completion of this pivotal Phase

3 CTCL study continues to be our top priority.

the third quarter, we initiated a pivotal double-blind, placebo-controlled Phase 3 clinical trial of SGX942 (dusquetide) for the

treatment of oral mucositis in patients with head and neck cancer receiving CRT. This trial, referred to as the "DOM-INNATE"

study (Dusquetide treatment in Oral Mucositis - by modulating INNATE immunity), aims to evaluate

the response of SGX942 in reducing the duration of severe oral mucositis, in addition to other clinically meaningful measures,

and incorporates feedback from the FDA as well as the EMA via the Scientific Advice process. The Scientific Advice from the EMA

indicated that a single, double-blind, placebo-controlled Phase 3 study, if successful, in conjunction with the positive results

from the Phase 2 dose-ranging study, generally will be sufficient to support a marketing authorization application for potential

licensure in Europe. SGX942 is the first Innate Defense Regulator in development for oral mucositis and has previously demonstrated

positive results in a Phase 2 clinical trial.

is a new chemical entity with 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. It also accelerates resolution of tissue damage following exposure

to a variety of agents including bacterial pathogens, trauma and chemo-and/or radiation therapy. Long-term follow-up data from

the Phase 2 trial, published in the second quarter of 2017, further indicated the safety and tolerability of SGX942 treatment,

with a sustained trend towards reduced mortality and increased tumor resolution compared to placebo. SGX942 has received Fast

Track designation from the FDA for the treatment of oral mucositis as a result of CRT in head and neck cancer patients as well

as PIM designation from the MHRA in the UK. In addition, the US Patent Office has granted the patent entitled "Novel Peptides

and Analogs for Use in the Treatment of Oral Mucositis". The newly issued patent claims 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

anticipate that approximately fifty US and European oncology centers will be participating in this pivotal Phase 3 study. Currently,

the study is actively enrolling in the US, which includes a number of centers that had previously participated in the Phase 2

study, with expansion into Europe occurring later this year. Current guidance on timing of study completion continues to be 2019,

with a prospectively defined, blinded interim analysis for the trial occurring in the first half of 2019.

addition to the ongoing funding of up to $24.7 million awarded by NIAID for the development of our ricin toxin vaccine, RiVax ,

we announced that biomarkers for RiVax testing have been successfully identified, facilitating potential approval

under the FDA Animal Rule. The FDA Animal Rule is applied to products where testing in human clinical trials would be unethical,

and in the case of ricin toxin, fatal. The Animal Rule combines safety studies in humans and efficacy testing in animals to facilitate

approval. Key to the application of the Animal Rule is the requirement to establish a correlation between the immune response

observed in clinical trials in healthy volunteers with the immune response demonstrated in animal efficacy studies.

2018, we intend to initiate a Phase 1/2 vaccine safety and immunogenicity study utilizing RiVax . In parallel,

efficacy studies in non-human primates are also planned in 2018, with initial results currently anticipated for late 2018. Identification

of a biomarker to facilitate demonstrating the correlation between animal and human studies is a significant accomplishment in

the RiVax development program. In addition to being protective and thermostable, RiVax has demonstrated

that a reduced number of vaccinations may be required to establish protection, potentially utilizing only two doses instead of

three. RiVax has received Orphan Drug designation from the FDA and as a new chemical entity, upon approval, has

the potential to qualify for a biodefense Priority Review Voucher (PRV). PRVs are transferable and can be sold, with sales in

recent years of up to $350 million.

closing, thank you for your interest and your continued support of Soligenix. We look forward to another productive year as we

further advance our development programs, and will strive to provide similar updates on a quarterly basis moving forward. Best

wishes to you and your families for a happy, healthy and prosperous 2018!

Christopher J. Schaber

and Chief Executive Officer

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,