Intercell AG (ICLL) announced the six months follow up data of its exploratory clinical phase-II study targeting treatment-naïve Hepatitis C genotype-1 patients. As previously reported in February 2008, in this trial the therapeutic Hepatitis C vaccine (IC41) comprising five synthetic T-cell peptides and Intercell's first-generation poly-Arginine adjuvant (IC30) disclosed a statistically significant reduction of viral load in the blood of chronically infected patients up to two weeks after the last vaccination. The current long-term follow up results show that this reduction was significantly more pronounced at six months after the final vaccination.

In the open label controlled multi centre phase-II study 50 genotype-1 patients, naïve to standard treatment were enrolled for receiving a treatment schedule consisting of intra-dermal IC41 vaccinations in biweekly intervals with topical application of the Toll-like receptor (TLR) agonist imiquimod. The previous analysis of 46 patients at two weeks after the last vaccination with IC41 showed already a statistically significant (p=0.001) HCV RNA decline of 0.2 log. The present follow-up data from 33 patients at six months after end of IC41 vaccination revealed an even greater viral load decline of 0.46 log (p=0.001). Interestingly, the virus decline (0.6 log) at the six months time point was most pronounced in patients with high initial viral load (> 2 million copies/ml). A parallel study arm conducted in 21 treatment-naïve patients where the imiquimod application was omitted, did not show a significant reduction of the viral load. Thus the results strongly support the notion that the future co-administration of a TLR adjuvant, like IC31, is pivotal for the therapeutic effect of the vaccine.

"Our study is the first report to show significant long-term viral load effects of therapeutic vaccination. In particular the increasing RNA decline up to six months after vaccination is extremely encouraging and finally suggests the formulation of our vaccine with IC31, a strong TLR agonist. Furthermore our vaccine in future trials may be combined with standard therapy or novel antivirals." states Alexander von Gabain, chief scientific officer of Intercell.

Although options for the treatment of chronic Hepatitis C with Interferon/Ribavirin have improved, treatment will remain very difficult and a significant unmet medical need, especially in the case of Genotype 1. Novel immunotherapies, and possibly therapeutic vaccines, might become an option in the arena of existing and future HCV combination treatments. Thus, Intercell will follow its development strategy that will also take advantage of an enlarged antigen portfolio and of IC31®, Intercell's second-generation adjuvant that has recently demonstrated the generation of T-cell responses, in human vaccine trials, to a level not yet seen for other known adjuvants.

HCV is a major cause of chronic liver disease, including cirrhosis and liver cancer.