Crucell reports positive results from Phase II rabies study

This Phase II trial was set up as a randomized, single-blind, controlled study in 140 healthy volunteers and tested the antibody product in association with Sanofi Pasteur human diploid cell rabies vaccine. The study compared the rabies monoclonal antibody combination to a currently marketed human rabies immune globulin or placebo, in association with the rabies vaccine in a simulated rabies post-exposure setting.

A total of 140 subjects were randomized into the study, 80 in the CL184 monoclonal antibody combination treatment group, 40 in the human rabies immune globulin group and 20 in the placebo group. All subjects completed the study. There was no serious adverse event reported.

Overall, the systemic safety was comparable in the placebo, the HRIG and the monoclonal antibody combination groups. Injection site reactions to the monoclonal antibody combination, the human rabies immune globulin or placebo were reported by 12.5%, 65 % and 30% of the subjects, respectively.

The neutralizing activity against the rabies virus (a surrogate marker for protection) provided by the monoclonal antibody combination was comparable to that provided by the comparator. By day 14, all subjects administered the monoclonal antibodies combination together with the rabies vaccine reached the level of 0.5 IU/ml, a neutralizing activity level thought to provide protection.

Of note, the development of the immune response to the rabies vaccine was comparable in the monoclonal antibody combination and the human rabies immune globulin groups. These encouraging preliminary results pave the way for the further development of this potentially life-saving medicine, the company said.

Ronald Brus, Crucell’s CEO, said: “We are very pleased with our continued and rapid progress with this next generation rabies treatment. These results and the milestone achieved put us another step closer to our ambition of reducing the global burden of this fatal disease.”