Janssen’s lead SARS-CoV-2 investigational vaccine candidate, Ad26.COV2.S, prevented severe clinical disease in Syrian golden hamsters when challenged with SARS-CoV-2, the virus that causes COVID-19 in people.

The data, published in Nature Medicine, show that the investigational adenovirus serotype 26 (Ad26) vector-based vaccine elicited an immune response as demonstrated by neutralising antibodies and prevented severe clinical disease, including weight loss, pneumonia and mortality, the firm said.

Publication of the data follows that showing that the vaccine elicited an immune response in a preclinical study in non-human primates (NHP), that correlated with protection against SARS-CoV-2, “providing complete protection against viral replication in the lungs”.

The latest research tested the vaccine candidate in Syrian golden hamsters because they are more susceptible to clinical disease than NHPs, which typically do not get severe disease, Janssen explained.

“This preclinical study further validates our confidence in our SARS-CoV-2 vaccine candidate,” noted Paul Stoffels, vice chairman of the Executive Committee and chief scientific officer at Johnson & Johnson.

“With our Phase III trials planned to start this month, we remain committed to expanding our manufacturing and distribution capabilities to enable global access to our SARS-CoV-2 vaccine candidate should it prove to be safe and effective in humans.”

End of the line for pimodivir in flu

The company also announced the end of development of pimodivir, an investigational antiviral treatment for influenza A infection.

This decision, it said, is based on recent results from pre-planned interim analyses of the pimodivir Phase III trial in hospitalised patients with influenza A, which that found pimodivir in combination with the standard of care (SOC) “was very unlikely to demonstrate added benefit”.

"While our goal was to develop an innovative new treatment option for patients at risk of respiratory infections, unfortunately these data show that pimodivir does not offer a benefit above the existing standard of care," said James Merson, Global Therapeutic Area head for Infectious Diseases at Janssen Research & Development.