The double-blind, randomised, adaptive, placebo-controlled trial analysed the impact of Tempol in Covid-19 patients.
It enrolled nearly 248 subjects aged 18 years and above. These patients received either a daily 800mg dose of Tempol or a placebo twice a day for up to 21 days.
According to the third interim assessment data from the trial, Tempol did not show statistical significance on the primary endpoint of sustained clinical resolution of disease symptoms at day 14 compared to a placebo.
Due to a lack of efficacy, the independent Data Safety Monitoring Board (DSMB) advised halting the trial early.
The board also noted no safety concerns in trial subjects treated with Tempol.
Based on the DSMB recommendation, the company stopped the study and will assess the unblinded trial results to decide on the further development of Tempol.
Adamis Pharmaceuticals chief medical officer Ron Moss said: “This trial did not meet its primary endpoint, but we are exploring the possibility that vaccinations and the less virulent variants [Omicron] during the trial period may have obscured an effect of Tempol.
“This speculation is based on the lower-than-expected observed hospitalisation rate in this trial [less than 1%], compared to other Covid-19 treatment trials.
“We will continue to analyse the data to determine if we believe Tempol can be utilised in other Covid patient populations, including those with more severe illness or immunocompromised.”
In June this year, the company reported that the DSMB overseeing the Phase II/III trial of Tempol for Covid-19 recommended the continuation of the study as planned.