Bavarian Nordic announces success of Phase 3 clinical trial for smallpox vaccine

Bavarian Nordic, a biotechnology company based in Denmark, announced this week the results of a successful Phase 3 clinical trial that demonstrated the safety and efficacy of its investigational, non-replicating smallpox vaccine, IMVAMUNE.

The U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) collaborated with the U.S. Defense Health Agency to enroll 440 subjects at a U.S. military post in South Korea in the clinical trial.

IMVAMUNE is being developed as an alternative to the current U.S. licensed replicating smallpox vaccine, ACAM2000, which certain populations, including people with atopic dermatitis and HIV, cannot use. IMVAMUNE has already been approved in Canada and the European Union.

The study found that the peak neutralizing antibodies induced by IMVAMUNE were two times higher than those stimulated by ACAM2000, demonstrating a statistically superior immune response.

The study also aimed to demonstrate an attenuation or prevention of a “take,” a measure of efficacy against smallpox in people vaccinated for the first time, in volunteers previously vaccinated with IMVAMUNE. Following the second vaccination, trial participants who had developed a protective immune response showed either a reduced take or none at all.

“If approved, this vaccine will have a direct impact on improving force health protection for U.S. Soldiers and other service members who are required to be immunized against smallpox,” Col. Gary Wheeler, commander of USAMRIID, said.

IMVAMUNE has been given to more than 7,800 subjects in 21 clinical studies, Paul Chaplin, president and CEO of Bavarian Nordic, said. He said that the company plans to file a Biological License Application with the U.S. Food and Drug Administration later this year.

“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 to protect the public from the deliberate release of the smallpox virus,” Chaplin said.