On Wednesday, August 23, 2023, it was announced that the pharmaceutical giant AstraZeneca is partnering with the biotech startup company Vaxess to develop prototype vaccines for pandemic influenza that can be administered through a shelf-stable skin patch instead of a shot. The skin patch is the proprietary technology, MIMIXTM Patch, by Vaxess, which explores silk fibroin as a delivery platform for the drug substance.
Vaxess was a startup spun out from Harvard University in 2012, headquartered in Cambridge, MA, USA. Vaxess currently has fewer than 100 employees and has gone through 19 rounds of funding, including grants, venture rounds, or series A/B rounds. The total funding it raised before the announcement of the AstraZeneca collaboration was $75M. Through this collaboration, Vaxess could receive up to $10.3M in joint efforts to develop and test up to 26 undisclosed mRNA vaccines with the skin patch through Phase I/II clinical study. This will be the first time Vaxess tests an mRNA vaccine patch in humans.
Vaxess started a Phase I trial (VX-103) of a seasonal H1N1 flu vaccine in collaboration with GC Biopharma Corp in 2022. On June 5, 2023, Vaxess announced the result from completion of the phase I trial: “180-day data showed the influenza vaccine patch elicited strong immune responses and was well-tolerated amongst volunteers.” The study was not found on the ClinicalTrial.gov website.
The MIMIX platform of Vaxess is using a microneedle skin patch with arrays of micro tips that contain pharmaceutical-loaded biomaterials made of natural silk fibers. After applying the patch to the patient’s skin, the micro tips will embed in the skin for sustained release, triggering an immune response for an elongated time compared to the conventional way of administration through a shot. It’s claimed to be pain-free, shelf-stable at room temperature, and slow-release.
A few things to consider about this technology:
1.How to ensure the even distribution of therapeutics in the final drug product?
The structure of the drug product (shown in Figure 1) looks very similar to the lipid nanoparticle (LNP) delivery platform, where the therapeutics (nucleic acids, proteins, or small molecules) are encapsulated in a structure, in this case, of silk components, water, etc. In LNP, one challenge is that many of the formulated LNP particles are empty. Would it also be a problem for this silk fibroin-based delivery platform as well?
2.Studies show that silk fibroin can decrease cell viability of human lymphocytes and monocytes due to oxidative stress when its concentration is higher than 0.5 mg/mL. Therefore, it is important to design the technology carefully so that it doesn’t induce toxicity towards human cells.
3.How to guarantee the accurate application of this microneedle skin patch among patients? This technology is designed so that patients can administer it at home by themselves, but there doesn’t seem to be a good way yet to monitor the successful administration.
Overall, this is a good technology that can address many of the challenges of current vaccines. For the Covid-19 vaccine, the drug product needs to be stored at -20C, or even -80C, which poses a huge challenge for its transportation and storage during the pandemic. Also, the needle-free idea is very appealing as well, especially among young kids or other people who are struggling with shots. However, whether it is compatible with different therapeutics or not remains to be seen.
Reference:
- https://www.vaxess.com/the-science
- Naserzadeh, Parvaneh, et al. “Evaluation of the toxicity effects of silk fibroin on human lymphocytes and monocytes.” Journal of Biochemical and Molecular Toxicology 32.6 (2018): e22056.