New flu vaccine super-adjuvant enters Phase I

IC31, developed by Austrian firm Intercell, is said to induce greater immunity than other adjuvants currently available, making it potentially very useful not only for seasonal vaccines but also pandemic and pre-pandemic treatments. Whereas many adjuvants currently used to boost immune responses triggered by vaccination stimulate a response only in the B-cells, Intercell claims that IC31 also produces a response in T-cells (both helper and cytotoxic) which bumps up the immune response. IC31 itself is a synthetic formulation that combines the immuno-stimulating properties of KLK (a short cationic peptide) and an immuno-stimulant oligodeoxynucleotide, ODN1a. IC31 is Intercell's second generation immuniser, and as a wholly synthetic chemical can be manufactured to high purity, uniform quality, and at low cost. The Phase I trial follows on from promising preclinical animal models that demonstrated IC31's ability to help stimulate increased haemaglutinin titers and specific T-cell responses "significantly". As well as this, Intercell claims that the presence of IC31 also induces high, long-lasting levels of flu-specific T-cells as well as the IgG2a antibody, both of which are associated with an immune response known to improve and broaden protection from flu infections. Many other adjuvants lack this ability to stimulate T-cell immunity, and offer only limited cross-protection against other flu strains. According to Intercell, IC31 overcomes these shortcomings, as well as allowing vaccine development where cellular immunity is critical (e.g. tuberculosis, chlamydia). The company will be developing the IC31 adjuvanted flu vaccine in-house but also intends to partner with other pharma firms on the project should an appropriate opportunity arise. Results of the Phase I trial are expected in early 2008, and the company anticipates the first market launch to be around 2011/2012. Intercell also already has good manufacturing practice (GMP)-compliant facilities in place in Scotland, UK, currently used for the production of its Japanese encephalitis vaccine which is due to enter the market in 2008. The first manufacturing approval inspection is expected later this year, with a US Food and Drug Administration (FDA) pre-approval inspection anticipated in early 2008. The company has partnered with several big names in vaccine manufacture already, including Merck & Co., Sanofi Pasteur and Novartis, and says it is collaborating with a number of global vaccine manufacturers and smaller biotechs on the use of IC31. In September last year the company signed a worldwide agreement with Wyeth Pharmaceutical for the use of IC31 in a variety of infectious disease vaccine programmes. While no details were released on any specific diseases Wyeth might be targeting with IC31-boosted vaccines, the deal could land Intercell around $77m (€57m), as well as further milestone payments and royalties on product net sales. IC31 has also shown promising results in trials as part of another collaboration with Danish group Statens Serums Institut (SSI). SSI opted for Intercell's IC31 adjuvant in the development of a novel tuberculosis vaccine. According to Intercell, Phase I trials completed earlier this year showed that IC31 "demonstrated an outstanding profile to stimulate a strong T-cell immune response in humans,"​ which helped proved the scientific concept of the novel adjuvant. Bolstered by these promising results, Intercell hopes to see the further applications of IC31 in a variety of prophylactic and therapeutic vaccines, and aims to establish the novel product as the "the gold standard for adjuvants"​.