EuroVacc’s lead vaccine platform is poxvirus-based vaccine candidate, in particular NYVAC. NYVAC is a highly attenuated vaccinia virus strain and has been used as a vector not just for HIV/AIDS vaccines but also for vaccines against other infectious diseases.
Development of NYVAC
The development of NYVAC, in collaboration with Sanofi Pasteur, was initially funded by the European Commission 5th Framework Programs, and more recently funded by the Collaboration for AIDS Vaccine Discovery (CAVD) of the Bill and Melinda Gates Foundation (BMGF). In addition to the replicating deficient NYVAC vector, funded by CAVD and in collaboration with Arizona State University, development of replication competent NYVAC vector is also under way.
EuroVacc has sponsored or co-sponsored multiple phase I/II clinical trials in Europe and Africa, in both prophylactic and therapeutic settings. The lead candidates in EuroVacc’s clinical program is based on DNA and NYVAC combination.
Why poxvirus vector-based vaccines?
There is a strong scientific, industrial and regulatory rationale for developing poxvirus vector-based vaccines
Poxvirus vector-based vaccines have a long development history and have proven to be efficacious at inducing therapeutic and protective immune responses in several infectious diseases and tumor immunotherapy models;
In the veterinary field, a number of safe and effective vaccines based on poxvirus vectors have been successfully developed to commercial products;
There is a robust production process in place;
The STEP trials have revealed potential association between pre-existing immunity to the vector and enhanced susceptibility to HIV infection. However, unlike Ad5 which is prevalent in more than 80% of the world population, smallpox has been eradicated and the smallpox vaccination program was stopped in 1974. Therefore, for poxvirus-based vaccines, the problem of pre-existing immunity does not apply to the majority of the population, particular in the developing countries;
The RV144 trial, is the first HIV vaccine trial demonstrated promising efficacy result, albeit modest. The trial evaluated a vaccination regimen of poxvirus vector vaccine (ALVAC) prime and protein boost. The modest efficacy data indicated that there is a need to improve the vaccine candidate. One approach for improvement is to evaluate potentially improved poxvirus vectors, such as NYVAC.