Vienna (Austria), December 12, 2006 - Intercell AG (VSE, "ICLL") announced today that it has completed a Phase II trial for its therapeutic Hepatitis C vaccine (IC41), where the vaccine was applied in combination with the standard Hepatitis C therapy (pegylated Interferon and Ribavirin - PegIFN- RBV) to patients infected with genotype 1. In the study, the vaccine administration was bound to the schedule of the first patient trial concluded in 2004 where route and frequency was still sub-optimal as compared to the improved induction of pivotal T cells achieved in recently concluded optimization trial.
In the current clinical trial, chronically infected Hepatitis C patients receiving standard therapy with PegIFN-RBV were enrolled in Germany, Austria and in the UK. 22 patients who had an early response at week 12 to standard therapy received vaccinations with IC41 as an add-on to standard therapy during the second half of their treatment (week 28 to 48).
The study proved a good safety profile of IC41 when used concomitantly with PegINF-RBV. Furthermore, the level of the critical T-cell response generated was similar to what had been seen in previous studies in which chronic patients or healthy subjects were vaccinated with IC41 alone, indicating that there was no apparent interference of PegIFN-RBV with vaccine immunogenicity. Moreover, it was observed that critical anti-HCV T-cell responses could only be measured in the group of non-relapsing patients (14 out of 22), whereas such responses were absent in the 8 relapsing patients. As expected, however, an improved relapse rate by the concomitant use of IC41 could not be demonstrated with statistical significance, given the use of the non-optimized vaccination schedule.
"Considering the well-known limitations of currently approved Hepatitis C therapies we are well on track with the development of our therapeutic vaccine. It was key to demonstrate that IC41 can be safely administered together with standard therapy, thus enabling the way to potential future combination therapies", states Alexander von Gabain, Intercell’s Chief Scientific Officer.
Intercell has recently initiated a Phase II proof-of-concept - efficacy study in chronic Hepatitis C patients. Here, an optimized immunization schedule will be applied to patients infected with genotype 1, who are naïve to treatment. The study aims to show a significant decline in HCV viral load, which would be a clinical proof of the mechanism of IC41, and an important milestone to further advance the development. This is particularly true in genotype 1 patients, where standard therapy achieves a sustained viral response only in less than half of treated patients.
IC41 - Clinical development strategy
After completion of a first Phase II clinical study in patients not responding to standard therapy in 2004, the clinical development program has been extended. A follow-up study has been designed to further increase the T-cell response, which is the most critical part of the immune system in the fight against the infection, by optimizing the route and the frequency of vaccinations.
Results of the optimization clinical trial, which was completed in Q1 2006, indicate that IC41, when given in optimized route and schedule, is considerably more immunogenic than has previously been shown. Based on these results, Intercell has started a Phase II Proof-of-concept study testing IC41 with this optimized schedule in a further Phase II clinical trial in patients with chronic Hepatitis C. This study aims to show sustained reductions of HCV-RNA through IC41 stand-alone therapy in a substantial subset of patients. Initial results of this study are expected in mid 2007.