Biopharmaceutical company Soligenix (OTCBB:SNGX) announced Wednesday further progress in the development of ThermoVax, the company's vaccine thermostabilization technology.
The company's technology allows vaccines that usually need to be refrigerated to maintain their efficacy at higher temperatures.
Soligenix said Wednesday that progress has been made based on the stability of prototype vaccines that have been kept at elevated temperatures for longer than three months.
Studies are being conducted as part of a continuing program to test the effectiveness of vaccines designed to withstand extremes of temperature and other environmental stress conditions.
The development of ThermoVax is being supported by a $9.4 million National Institute of Allergy and Infectious Disease (NIAID) grant, for biodefense indications against ricin toxin and anthrax exposure.
In February, Soligenix established proof-of-concept for its thermostabilization technology using its aluminum-adjuvant ricin toxin RiVax vaccine. Results from this study showed the vaccine retained effectiveness and potency, while stored at 40 degrees Celsius for one month, when combined with the ThermoVax technology, the company said.
Confirmatory results, Soligenix added, have now extended this initial time frame to more than three months when the vaccine is kept at 40 degrees Celsius.
In contrast, the liquid RiVax vaccine, when stored at 40 degrees Celsius, rapidly degraded and no longer maintained its effectiveness, the company said. This is because the ricin A chain is typically sensitive to temperature and quickly loses its ability to induce neutralizing antibodies when exposed to higher temperatues than 8 degrees Celsius.
But ThermoVax is able to produce "stable and potent" vaccine formulations, Soligenix said, by combining lyophilzation technology with conventional aluminum adjuvants, secondary adjuvants (for rapid onset of immunity), and protein subunits.
The lyophilization process is often employed to extend the shelf life of drugs, by removing the water from the pharmaceutical preparation. Vaccines that undergo this process often lose their potency, especially if the vaccine is made with aluminum salt adjuvants, as most are.
As a result, most vaccine products must be kept under tightly controlled conditions, as the World Health Organization (WHO) estimates that about half of all global vaccine doses are wasted for not being kept within required temperature ranges.
Soligenix's technology, however, achieves this lyophilization effect but maintains the sensitive material in the vaccine, making the technology especially valuable for biodefense or pandemic situations, where drugs need to be stockpiled for a long period of time.
"We continue to be pleased with the data generated thus far with ThermoVax," said chief scientific officer, Dr. Robert N. Brey.
"The ability of vaccines to withstand extreme temperatures is a significant step forward in vaccine technology.
"ThermoVax may also enable preparation of otherwise difficult multivalent (protective against multiple pathogens) formulations. We plan to apply ThermoVax to other conventional vaccines that require refrigeration."
The underlying technology was developed by Drs. John Carpenter and Theodore Randolph at the University of Colorado, whose team performed the studies along with Dr. Nicholas Mantis of The New York State Department of Health in Albany.
The company said the elimination of the cold chain would also boost the utility of these vaccines for emerging markets, and for other applications requiring but lacking reliable cold chain capabilities, which add considerable cost.
Soligenix is a development stage biopharmaceutical company, developing products to treat life-threatening side effects of cancer treatments and serious gastrointestinal diseases, as well as vaccines for certain bioterrorism agents.
Through its biodefense division, Soligenix is developing its SGX204 vaccine, which is designed to protect against the lethal effects of exposure to anthrax, in addition to RiVax.