Potential RSV vaccine achieves regulatory step in US

Bavarian Nordic vaccine candidate used hVivo challenge trial to gather data

The US Food and Drug Administration (FDA) has granted breakthrough therapy designation for a vaccine candidate for respiratory syncytial virus (RSV).

Bavarian Nordic’s MVA-BN RSV was granted the designation, which is designed to expedite the development and regulatory review of medicines to treat a serious condition, based on preliminary clinical evidence indicating that the vaccine candidate may demonstrate substantial improvement over available therapies.

Open Orphan subsidiary hVivo, conducted a Phase 2, double-blinded, placebo controlled human challenge trial to assess the vaccine candidate. That study provided a significant portion of this preliminary evidence.

The challenge study found a significant reduction in viral load in vaccinated subjects versus the placebo, and vaccinated subjects showed a significant reduction in clinical symptoms typically associated with RSV infections. It demonstarted a vaccine efficacy of up to 79 per cent in preventing symptomatic infections, and no vaccine-related serious adverse events were observed.


Open Orphan executive chairman Cathal Friel welcomed the breakthrough therapy designation.

“This highlights a major benefit of human challenge trials, in that they enable drug developers to obtain Phase 2/2a efficacy data for their vaccine and antivirals candidates in a fast, cost-effective manner ahead of larger scale studies,” he said. “This data can then strengthen submissions for important regulatory programmes such as the breakthrough therapy designation.”

Ciara O'Brien

Ciara O'Brien

Ciara O'Brien is an Irish Times business and technology journalist