The San Francisco, California-based firm’s oral delivery platform incorporates a recombinant antigen and an adenovirus vector combined with a TLR3 (toll-like receptor-3) ligand adjuvant in an enteric coated tablet, delivered to the epithelium of the small intestine where the vaccine activates an immune response.
Its lead candidate, an oral solid dosage form of an influenza vaccine being examined in Phase II trials, has already been found to be comparable to injectables.
And at the Bioprocessing International (BPI) European Summit last week, Emery Dora – corporate development associate at Vaxart Inc – described his company’s technology as a “gamechanger” for vaccines.
“We really feel that this is a paradigm shift, having a tablet vaccine which is efficacious, that can work as well or exceed that of injectables really gives us a good advantage,” he told delegates in Amsterdam.
So far, Vaxart has been working with contract manufacturing organisations (CMOs) to produce its recombinant virus for use in clinical trial batches.
“We’ve been working primarily with Lonza in Texas and have a drug master file in place with them but we do not have any contractual long-term obligations with them, so we are currently looking at a couple of other CMOs to handle our capacity for a number of clinical trials moving forward,” he said.
“We’ve also been doing exploration in-house,” he continued. “While having a lot of expertise with producing recombinant adenovirus [Lonza] primarily produces it for gene therapy purposes for which you need extremely high purity.
“For us we’re doing a tablet vaccine which is going to the gut, not any point to become systemic, so we want sanitary conditions but we don’t need these extremely pure conditions that Lonza has optimized its processes for.”
Vaxart has built a dedicated manufacturing facility in South San Francisco and according to Dora has been able to “generate yields of the recombinant virus in house which far exceeds what we’ve seen at Lonza,” although not at the 2,000L bioreactor capacity seen with the CMO.
Sanitary, not sterile
And Dora added Vaxart’s platform also has manufacturing benefits it could implement in-house due to its tableting, rather than injectable, manufacturing processes.
“We’re looking for sanitary fill/finish rather than sterility, and given the fact we don’t need to use syringes, we don’t [need to] have any downstream trained technicians to administer this,” he said, adding the platform also bypasses the cold chain, as products are stable at room temperature for up to a year with a minimal drop in efficacy.
“It’s going to lower our overall CAPEX as well as our production costs,” he said, adding already the firm has demonstrated it can produce 100,000s of doses per day in-house.
On top of the influenza candidate, Vaxart has clinical trials running for Norovirus and RSV vaccines.