The United States Food and Drug Administration (FDA) granted breakthrough therapy designation to a Bavarian Nordic A/S vaccine candidate known as MVA-BN RSV this week, setting the preventative for RSV up for a hastened review and development cycle.
The vaccine’s focus, known as respiratory syncytial virus or RSV, is a common virus that, for most, causes mild, cold-like symptoms. However, it has also been affiliated with severe lung infections, particularly among infants, older adults, and the immunocompromised. Studies have shown that approximately 14,000 U.S. adults at least 65 years old die of complications from RSV each year. MVA-BN RSV would become the first approved vaccine for the virus if approved.
“The development of an RSV vaccine is one of our main priorities that could help fulfill the significant unmet need for a preventative therapy, particularly for the elderly who may be at risk from serious complications from the disease,” Paul Chaplin, president and CEO of Bavarian Nordic, said. “Our candidate has a clearly differentiated approach, as it employs five RSV-specific antigens with an aim to stimulate a broad antibody and cellular immune response against RSV. Based on the encouraging results demonstrated in a human challenge trial last year, we recently announced our plans to initiate a Phase 3 study this year and look forward to working closely with the FDA on our path towards licensure of the vaccine.”
Results of a Phase 2 placebo-controlled trial of 61 subjects last year showed a significant reduction in viral load among those vaccinated by MVA-BN RSV. Its efficacy settled at approximately 79 percent. A separate Phase 2 trial of 421 subjects 55 years old and older confirmed the vaccine to be well-tolerated and generating broad, durable antibody and T-cell responses against RSV, along with mucosal immune responses.
A larger Phase 3 trial is scheduled for this year.