Research institute wins $11.9m NIH contract to make thermostable TB vaccine
The contract has a base award of $3.6m but could reach $11.9m if all milestones are achieved. The contract provides funding for a team of IDRI scientists – led by Christopher Fox – to develop, produce and test a thermostable lyophilized formulation of its vaccine candidate to prevent tuberculosis.
“Vaccines contain inherently labile components such as proteins that are sensitive to elevated temperatures and other stresses. Through appropriate formulation and drying technologies (such as lyophilization), the tendency for vaccine degradation at elevated temperatures can be significantly reduced,” Fox told BioPharma-Reporter.com.
TB-causing bacteria infect an estimated one-third of the global population, and, in 2013, approximately nine million developed active cases of TB.
IDRI’s vaccine component, ID93, which consists of a recombinant fusion of four TB antigens, has recently completed a Phase I clinical trial demonstrating good safety at different doses in healthy adult volunteers. IDRI's adjuvant component, GLA-SE, was evaluated together with ID93 as a liquid mixture in the same clinical trial at two different adjuvant doses, maintaining a good safety profile, the institute announced.
IDRI conducted successful preliminary studies showing that ID93 and GLA-SE “can be co-lyophilized to generate a single-vial dried vaccine that maintains protective biological activity even after exposure to 122 degrees Fahrenheit for one month," said Fox. The results of those preliminary studies were published in the Journal of Controlled Release earlier this year.
According to Fox, the contract could result in the first clinical emulsion-based adjuvant formulation to be successfully lyophilized. "To our knowledge, no one has demonstrated being able to lyophilize an oil-in-water emulsion-based adjuvant that maintains the same physicochemical properties after reconstitution as it had before lyophilization so this will be a new step in creating temperature stable vaccines for the future," he said.
“Adjuvant formulations such as oil-in-water emulsions play a critical role in enhancing and shaping immune responses; however, these adjuvant properties are dependent on the physical properties of the formulation,” Fox told us. “Oil-in-water emulsions consist of nano-size droplets that tend to aggregate under lyophilizing conditions unless appropriate excipients and manufacturing processes are employed to maintain the same particle size and other physical properties even after reconstitution, representing a significant development challenge.”
Most vaccines have a shelf life of about two years or longer only if they are continuously stored at refrigerated conditions of 36-46 degrees Fahrenheit.
The process of lyophilizing – or freeze-drying – a vaccine increases its shelf life and helps to address the issue of keeping it cold, which could eventually allow vaccines to be shipped throughout the world without the necessity of a continuous cold chain or separate antigen/adjuvant vials.
IDRI's partner for this contract include Lyophilization Technology, a contract development and manufacturing organization providing lyophilisation services.
As far as the timeline for the TB vaccine, Fox told us that formulation and manufacturing development activities are planned for about three years, following which advanced preclinical and Phase I clinical testing are planned for another three years.