Benzinga | Dec 2, 2021 07:34AM EST

Soligenix Announces Successful Protection Using A Bivalent Thermostabilized Filovirus Vaccine

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 100% protection of non-human primates (NHPs) against lethal Sudan ebolavirus (SUDV) challenge using a bivalent, thermostabilized vaccine formulated in a single vial, reconstituted only with water immediately prior to use. This milestone is part of an ongoing collaboration with the University of Hawaii at Mnoa (UHM), demonstrating the successful presentation of one or more antigen(s) within the same formulation while maintaining full potency and thermostability. It further demonstrates the broad applicability of the vaccine platform, and its potential role in the US government's initiative for pandemic preparedness. This same heat stable vaccine platform has also been applied to the development of a COVID-19 vaccine, CiVax(tm), which the Company anticipates testing against the new omicron variant, having shown immunogenicity against previous variants including delta.

The antigens and adjuvants used in this study have been previously shown to protect NHPs from subsequent infection, and represent the only recombinant subunit vaccines that have demonstrated efficacy against Zaire ebolavirus and other filoviruses in NHPs. Lyophilization of the antigens within monovalent vaccine formulations has also been demonstrated to thermostabilize the antigens at temperatures as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to 12 weeks, enabling storage at ambient temperature. No currently approved lyophilized vaccine that contains adjuvant is presented in a single vial format and there are few reports of successfully using nano-emulsions in lyophilized formulations. Previous work has demonstrated the use of a single vial platform to co-lyophilize antigen(s) and a nano-emulsion adjuvant, CoVaccine HT(tm), maintaining key adjuvant stability characteristics including particle size and colloidal stability, as well as maintaining immunogenicity. This most recent milestone confirms that in the context of lethal challenge with Sudan ebolavirus, complete protection is maintained with the thermostabilized formulation.

"Filoviruses such as Zaire ebolavirus, Sudan ebolavirus and Marburg marburgvirus are some of the most lethal viruses known, and they are endemic in areas of the world where the power supply and distribution network can be uncertain. There are no vaccines for either Sudan ebolavirus or Marburg marburgvirus, while vaccines for Zaire ebolavirus are constrained by cold chain logistics. A heat stable vaccine in a single vial format would significantly enhance any public health preparedness or response to a new outbreak, at its source," stated Axel Lehrer, PhD, Associate Professor, Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine (JABSOM), UHM. "Our work to date has demonstrated the feasibility of rapid and efficient manufacturing, as well as the ability to thermostabilize multiple antigens that can then be stored at temperatures exceeding 100 degrees Fahrenheit. Having a vaccine platform available such as this has the potential to accelerate worldwide vaccination campaigns addressing future health emergencies, including another global pandemic like the one we are unfortunately experiencing with COVID-19."

"Our next generation combined vaccine platform includes three major components: a robust protein manufacturing process that has been demonstrated on multiple protein antigens, a novel nano-emulsion adjuvant which induces broad immunity and a formulation procedure which enables thermostabilization of the combination of adjuvant and antigen in a single vial," stated Oreola Donini, PhD, Senior Vice President and Chief Scientific Officer of Soligenix. "Elements of this vaccine platform have been utilized in our ricin toxin, filovirus and COVID-19 vaccine candidates, indicating its broad applicability. The ability to package more than one vaccine candidate in a single vial platform further adds to their developability, whether as a multivalent or individual monovalent vaccine, particularly against Marburg marburgvirus and Sudan ebolavirus where there are currently no available vaccines."

Under the Company's Public Health Solutions business segment, ongoing collaborations with Dr. Lehrer, as well as work conducted by Theodore Randolph, PhD, Professor, Center for Pharmaceutical Biotechnology, Department of Chemical and Biological Engineering at the University of Colorado, Boulder have demonstrated the feasibility of developing thermally-stable subunit protein vaccine formulations for filoviruses. The thermostabilized filovirus vaccine program is continuing to advance with the support of a National Institute of Health (NIH) grant (R01-AI132323; awarded to the University of Hawaii) and a Small Business Innovation Research grant (#1R44AI157593-01; awarded to Soligenix). Work to date has demonstrated the compatibility of lyophilizing both antigen and adjuvant in the same vial, with reconstitution with sterile water for injection immediately prior to use. This simple delivery format, as well as the compatibility with ambient storage, enables vaccines that significantly reduce the logistical hurdles that have been required for addressing the current pandemic or deployment of other Ebola virus vaccines in recent outbreaks in Central and West Africa.