Bavarian Nordic announces positive results from pivotal Phase 3 study of IMVAMUNE smallpox vaccine

Bavarian Nordic has announced results from the first of two pivotal Phase 3 studies of the liquid-frozen formulation of IMVAMUNE® supporting a Biologics License Application for US approval of the vaccine.

In addition, the Company announced results from a pivotal Phase 2 study of freeze-dried IMVAMUNE smallpox vaccine supporting the clinical requirements for an Emergency Use Authorisation, which would allow for stockpiling of this next-generation of the vaccine. 

Safety profile of IMVAMUNE was confirmed in the largest clinical study performed to date

In the Phase 3 study, 3,000 subjects were vaccinated with three different manufacturing lots of the liquid-frozen IMVAMUNE formulation and compared to 1,000 subjects that received placebo. The three lots of IMVAMUNE induced equivalent antibody responses, meeting the primary endpoint of the study, while the favourable safety profile of IMVAMUNE was confirmed in this largest clinical study performed to date. Despite close cardiac monitoring of all subjects, no serious adverse reactions were reported among the 3,000 subjects vaccinated with IMVAMUNE, confirming the results of a smaller Phase 2 placebo controlled study. This clearly differentiates the safety profile of IMVAMUNE when compared to traditional smallpox vaccines that have recorded high rates of cardiac complications in healthy vaccines.

The Phase 2 study compared the safety and immunogenicity of a freeze-dried and a liquid-frozen formulation of IMVAMUNE and enrolled 650 vaccinia-naïve healthy subjects who were randomised to receive either formulation of IMVAMUNE. The freeze-dried vaccine induced an equivalent antibody response as the liquid-frozen version, meeting the primary endpoint of the study. Both formulations recorded a similar safety profile, confirming that the clinical data generated cumulatively in more than 7,600 vaccinated subjects is relevant for both formulations of IMVAMUNE.  

Results support stockpiling of the freeze-dried version of IMVAMUNE

The results provide the final clinical data required to support stockpiling of the freeze-dried version of IMVAMUNE in the US Strategic National Stockpile. Supported by a contract option of US $22 million exercised by the Biomedical Advanced Research and Development Authority (BARDA) in 2014, Bavarian Nordic is currently working to transfer the freeze-drying process to a new manufacturing line with a larger commercial capacity. These manufacturing activities remain on-track to be finalized this year, which is the final step towards meeting the regulatory requirements to stockpile the freeze-dried version of IMVAMUNE. 

Paul Chaplin, President & Chief Executive Officer of Bavarian Nordic, said: “Completing this pivotal Phase 2 study is a significant step in the transition to the freeze-dried version of the vaccine, which provides a number of advantages for the future procurement and stockpiling, thereby broadening the commercial potential. We remain on track to complete the transfer of the manufacturing process which will enable us to start deliveries in 2016, as we look forward to continuing our successful long-standing collaboration with the US Government on their public health preparedness.”