On Sept. 15, 2020, Soligenix, a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced publication of nonclinical results characterizing filovirus protein antigens (including for Ebola and Marburg viruses) and their thermostabilization.  The article, authored by collaborators at the University of Colorado, University of Hawaiʻi at Mānoa (UHM) and Soligenix, is titled, “Preservation of Quaternary Structure in Thermostable, Lyophilized Filovirus Glycoprotein Vaccines: A Search for Stability-Indicating Assays” and has been accepted for publication in the Journal of Pharmaceutical Sciences.

Under the Company’s Public Health Solutions business segment, ongoing collaborations with Axel Lehrer, PhD, Associate Professor, Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine (JABSOM), UHM and Hawaii Biotech Inc. (HBI), 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 heat stable subunit protein vaccine formulations for filovirus vaccines.  Protective efficacy has been demonstrated in non-human primates against infection with Ebola virus, Sudan virus, and Marburg virus. 

Formulation conditions have been identified to enable heat stabilization of each antigen, alone or in combination, for at least 12 weeks at 40 degrees Celsius (104 degrees Fahrenheit).  These most recent results demonstrate the thermostabilization of three virus glycoproteins (from Zaire ebolavirus, Sudan ebolavirus and Marburg marburgvirus), and the identification of key stability-indicating assays to further support mono-, bi- and tri-valent vaccine formulations. 

Ebola Virus Disease is caused by one of six species of Ebolavirus, four of which are known to cause disease in humans, including its best-known member, Zaire ebolavirus (Ebola virus).  All species of ebolavirus belong to the Filoviridae family, a family that further contains the equally human pathogenic Marburg virus.  Filoviruses are believed to be harbored in various animal species in Africa, particularly bats, although the specific reservoir host for many of these viruses is still unknown.  There have been several known Ebola and Marburg virus disease outbreaks since 1967, with the largest outbreak starting in 2014 in Western Africa, and involved over 26,000 confirmed/probable/suspected cases with an estimated death toll of over 11,000 people according to the Centers for Disease Control and Prevention (CDC), including some cases in Europe and the United States.

Transmission of filoviruses requires direct contact with bodily fluids from an infected person or contact with infected animals.  The mortality rate from filovirus infections are extremely high, and can sometimes be affected by the quality of supportive care available with a focus on early initiation of treatment.  Resolution of the disease largely depends on the patient’s own immune system.  There is no approved treatment for Ebola or Marburg although research into both has accelerated since the onset of the 2014 outbreak and significant progress has been made in advanced clinical testing of immunotherapeutics for Zaire ebolavirus. There is an approved vaccine, requiring storage at less than -60°C for Ebola virus (Zaire ebolavirus), but no protection is yet available for Marburg virus (Marburg marburgvirus) or Sudan virus (Sudan ebolavirus).