Soligenix, Inc., a late-stage biopharmaceutical company, has extended its development agreement with Emergent BioSolutions to implement a commercially viable, scalable production technology for the RiVax drug substance protein antigen.

RiVax is a vaccine candidate being developed to protect against ricin exposure.  This specific agreement will build upon process development work conducted to date in support of manufacturing scale-up that will eventually be performed in accordance with current good manufacturing practices (cGMPs) at Emergent's manufacturing facility located in Baltimore, Maryland.  

Soligenix has been developing RiVax, in conjunction with its heat stabilization technology, ThermoVax, as a heat-stable biodefense vaccine.  RiVax has demonstrated both 100% protection in a preclinical model of lethal ricin exposure and stability up to 1 year at 40 degrees Celsius facilitating storage at ambient temperature.  RiVax is being developed as a safe and effective biodefense vaccine which does not require cold chain shipment and storage.

The RiVax project has been funded with Federal funds of up to $24.7 million from the National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272201400039C.  The agreement between Soligenix and Emergent is specifically funded under this same contract.

"We are pleased to extend our agreement with Emergent BioSolutions as we expand our efforts to develop an effective, first-in-class vaccine against ricin toxin exposure in combination with our thermostabilization technology," stated Christopher J. Schaber, PhD, president and chief executive officer of Soligenix.  "Collaborating with NIAID and Emergent is an important step in advancing the development of our ThermoVax technology platform. Soligenix intends to use this innovative technology to develop a heat stable ricin toxin vaccine that meets US Government requirements and advances a vaccine thermostabilization platform that may apply to other vaccines."

"Emergent's overarching focus on medical countermeasures that address public health threats complements the objectives of this program. We look forward to leveraging our contract manufacturing expertise and flexibility to help meet Soligenix's needs," stated Adam Havey, executive vice president and president, Biodefense Division at Emergent BioSolutions.

Ricin toxin is a plant toxin and potential biological weapon because of its stability, high potency, and availability as a by-product of castor oil production.  Ricin comes in many forms like powder, mist, or pellet. Ricin can also be dissolved in water and other liquids.  The US 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 getting inside the 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 whole 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.

RiVax is Soligenix's proprietary 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 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 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 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.

The development of RiVax has been sponsored through a series of grants and contracts 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 originated.  To date, Soligenix and Dr. Ellen Vitetta and colleagues at UTSW have collectively received approximately $50 million in grant and contract funding from NIAID for development of RiVax and related vaccine technologies.  RiVax would potentially be added to the Strategic National Stockpile and dispensed in the event of a terrorist attack.

ThermoVax is a technology that is designed to eliminate the standard cold chain production, distribution and storage logistics required for most vaccines. Cold chain requirements add considerable cost to the production and storage of current conventional vaccines.  According to the Biopharma Cold Chain Sourcebook of 2010, more than 90% of all vaccines (with a total value of $20.6 billion) require shipment through cold chain.  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.  Further, the World Health Organization (WHO) reports that as much as 50% of all global vaccine doses are wasted due, in part, to excursions outside required temperature ranges.  

Soligenix is a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need.