- Copenhagen-based Bavarian Nordic A/S has announced a second positive Phase 3 study for Imvamune, with the investigational, non-replicating smallpox vaccine meeting both primary endpoints. Shares ticked up around 5% on the news.
- Peak neutralizing antibodies were two-fold higher than those triggered by ACAM2000, the current U.S. licensed replicating smallpox vaccine, showing both non-inferiority and significant superiority.
- Vaccination with Imvamune also reduced or prevented "vaccine take," a measure of a protective response. The biotech plans a biologics application in the second half of 2018, with fast track designation.
Smallpox was eradicated in 1967, with the last endemic case in Somalia in 1977. However, vaccines are still important for people who might be at high risk of exposure, for example in cases of bioterrorism.
ACAM2000, a smallpox vaccine from Sanofi SA subsidiary Acambis plc, first gained Food and Drug Administration approval in 2007. The risks of serious adverse effects are high, however, so the vaccine is only available through the Centers for Disease Control and Prevention, and as part of the Strategic National Stockpile.
In addition, live replicating smallpox vaccines can't be given to certain groups of people, such as those with HIV or atopic dermatitis. Imvamune's non-replicating nature provides it with an advantage, as it could be given to a wider group of people, in order to protect against a deliberate release of the smallpox virus.
The Phase 3 trial involved 440 people at a U.S. military garrison in South Korea, led by the U.S. Army Medical Research Institute of Infectious Diseases in collaboration with the U.S. Defense Health Agency. Bavarian Nordic has delivered 28 million liquid frozen doses to the National Stockpile, as well as having a contract with the Biomedical Advanced Research and Development Authority to replenish the stockpile with a freeze-dried formulation.
"This program has only been possible through the consistent and strong support of numerous U.S. government agencies and demonstrates what can be achieved through a successful public-private partnership," said Paul Chaplin, CEO of Bavarian Nordic.
If Imvamune is approved, Bavarian Nordic will be eligible for a valuable priority review voucher, which it can use to boost the review of a future therapeutic, or sell to another drug developer for tens or even hundreds of millions of dollars. Imvamune is already available in Canada, and also in Europe under the Imvanex trade name.