(Sharecast News) - Synairgen announced on Thursday that it was pausing clinical trial activities on its 'SNG001' compound in the treatment of Covid-19, at the behest of American authorities.

The AIM-traded firm said that, due to the need to modify the study design in light of the emergence of the Omicron variant, the US National Institutes of Health (NIH) had asked Synairgen to temporarily pause activities to prepare clinical supplies for the 'ACTIV-2' phase 3 trial until the timeline for the activation of the agent in the trial was clarified.

It was also still awaiting the phase 2 data from the US NIH ACTIV-2 trial in home-based Covid-19 participants, which was expected by the middle of the year.

Synairgen also announced that in-vitro studies conducted at Viroclinics-DDL in the Netherlands showed SNG001 had "potent antiviral activity" against SARS-CoV-2 Delta and Omicron variants, at concentrations that were readily achievable following inhaled delivery of interferon beta.

Finally, as it announced on 21 February, Synairgen said it was in the process of analysing the topline and full dataset from the 'SPRINTER' phase 3 study in order to better understand all of the findings.

"The findings of this analysis will be announced without delay once complete in accordance with regulatory obligations and presented and/or published in a peer-reviewed journal," the board said in its statement.

"The SPRINTER trial pointed to an encouraging trend in prevention of progression to severe disease and death - 36% reduction in the pre-defined per protocol population - which the company and its clinical advisors strongly believe merits further investigation in a platform trial which the company is actively investigating."

At 1201 GMT, shares in Synairgen were up 35.43% at 25p.