Phase 2 Study Launched for Respiratory Virus Vaccination

Respiratory syncytial virus infections can potentially be fatal for older adults and children.

Bavarian Nordic recently announced the initiation of a phase 2 clinical study of their experimental vaccine, MVA-BN RSV.

MVA-BN RSV is a vaccine candidate against respiratory syncytial virus, which is a common cause of bronchiolitis and pneumonia in infants and older adults. Respiratory syncytial virus can also cause a large number of hospitalizations and deaths per year, according to a press release from Bavarian Nordic.

Approximately 64 million people are infected each year, but there is currently no vaccine against the virus. Yearly infections and deaths in children are similar to those from the flu.

The US-based study will include 400 healthy patients age 55 and older. Patients will be randomized into 5 groups, and will receive 2 administrations of high or low dose MVA-BN RSV and/or placebo, according to the release.

The clinical trial is designed to find the ideal dose and schedule for the vaccine to be used in further studies. Bavarian Nordic is expected to announce top-line results in mid-2017 that will provide information for a phase 2b efficacy study.

The vaccine is designed to target 5 respiratory syncytial virus proteins to provide an expansive immune response against respiratory syncytial virus subtypes A and B. Preclinical studies have indicated that the MVA-BN RSV vaccine can create a balanced immune response with antibodies and T cells, similar to those elicited through a natural respiratory syncytial virus infection, according to the release.

The phase 1 clinical trial studied MVA-BN RSV in healthy adults, and showed that the vaccine increased antibodies and T cells against the subtypes. The vaccine was well-tolerated and patients did not experience unexpected or serious reactions.

A majority of adverse events were typical for vaccines, according to Bavarian Nordic.

“Advancing our RSV program into phase 2 is an important milestone for Bavarian Nordic in our efforts to develop a vaccine which potentially offers broad protection against the virus. RSV remains an area of high unmet medical need with no approved vaccine available,” said Paul Chaplin, president & chief executive officer of Bavarian Nordic. “This phase 2 study represents an essential step in the successful development of any vaccine; to ensure we establish an ideal dose and dosing regimen, prior to exploring this candidate in larger studies. In this study we will evaluate both a single vaccination, as well as a prime-boost approach that will determine which regime induces prolonged immune responses against RSV."