The clinical trial was a randomized, double-blinded, placebo controlled study in healthy volunteers that tested the human monoclonal antibody cocktail against rabies alone, in a dose escalation design, as well as in combination with a rabies vaccine. In the first, blinded, part of the study, in which solely the antibody cocktail was given, rabies virus neutralizing activity could be demonstrated at both dose levels that were administered. In the second, open, part of the study, in which the rabies antibody cocktail was administered in combination with a rabies vaccine, all volunteers seroconverted within 14 days upon the initiation of treatment. A level of rabies virus neutralizing activity (> 0.5 IU/ml) was achieved that is considered to provide protection against the deadly virus, proving that the antibody cocktail can be safely co-administered in line with standard therapy.
The data from the Indian study confirm and extend the results of the first-in-human Phase I study conducted in the US. The combined data from both Phase I studies prompt the progression towards Phase II studies, which are expected to start in the first half of 2008 in the US and the Philippines.
Crucell is developing the rabies antibody cocktail for the post-exposure prophylaxis of rabies. The antibody cocktail is a combination of two human monoclonal antibodies and is produced with the use of Crucell’s MAbstract and PER.C6 technologies. Crucell has already contracted DSM Biologics, its alliance partner for the PER.C6 technology platform, for the process validation and manufacturing of antibody batches for Phase III clinical efficacy studies.