Bavarian Nordic has already bagged approvals for its smallpox vaccine Imvamune in Canada and as Imvanex in the EU. Now it's one step closer to the finish line in the U.S., as the biotech has finished enrollment of the last of two phase 3 studies needed for an FDA green light.
With the study, the Danish vaccine company is seeking to prove that liquid-frozen Imvamune is not functionally inferior to ACAM2000, the smallpox vaccine currently licensed in the U.S.
A key difference is that Imvamune is a nonreplicating vaccine while ACAM2000 is replicating, meaning Imvamune can be used in people for whom usage of the replicating version is restricted such as those with HIV or atopic dermatitis. Additionally, Bavarian Nordic touts its vaccine's safety profile as free of some complications or adverse events sometimes associated with traditional replicating smallpox vaccines.
In the first round of the phase 3 study involving 4,000 unvaccinated healthy individuals—the largest clinical study on the vaccine to date—investigators confirmed the vaccine’s safety and that it produced antibody responses.
For the new trial, the company enrolled 440 subjects 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. The study is expected to be finished within the second quarter of 2017, and data will be available later that year.
Through this trial, the company is working to gain FDA approval for the liquid-frozen version as it separately advances a freeze-dried vaccine version. In 2009, the company won a contract to develop the latter formulation with a shelf life of approximately 10 or more years and to reduce the stockpiling costs.
Even though Imvamune has not officially gained an approval just yet, its efficacy is still to some extent recognized by the U.S. government. Studies on development of both the freeze-dried Imvamune vaccine and the liquid-frozen version have been funded with federal money.
So far, the company has provided 28 million doses of liquid-frozen Imvamune to the national stockpile. As the company’s third-quarter financial report shows, sales of Imvamune to the U.S. government generated 423 million Danish krone (about $60 million), constituting about 72% of the company’s entire 591 million Danish krone (about $84 million) revenue for the first three quarters of this year.
Elsewhere in its pipeline, Bavarian Nordic has high hopes for its prostate cancer vaccine Prostvac and has entered into a collaboration with Bristol-Myers Squibb to test potential combo approaches. The company is also developing an early-stage RSV vaccine.