Synairgen has reported that the global Phase III clinical trial of SNG001 in hospitalised Covid-19 patients failed to meet its primary or secondary efficacy endpoints.
An inhaled formulation, SNG001 contains the broad-spectrum antiviral protein interferon beta.
In the Phase III SPRINTER trial, 623 subjects were randomised to receive either SNG001 or placebo, apart from standard of care (SOC).
The primary analysis was carried out in the intention-to-treat population (ITT) while subjects with major protocol violations that may have tainted the results are excluded from the per protocol (PP) population.
The primary endpoints of the trial were time to hospital discharge and time to recovery to ‘no limitation of activities’ on the WHO ordinal scale for clinical improvement through day 28.
Subjects in the SNG001 arm were found to have comparable days to be discharged from the hospital with those treated with placebo.
Furthermore, in the SNG001 arm, patients had no improved chances of time to recovery versus the placebo arm, in the ITT as well as PP populations.
Synairgen noted that the changes in SOC during the Covid-19 pandemic could have compromised SNG001’s ability to demonstrate a clinical benefit on the primary endpoints.
Progression to severe Covid-19 or morality, progression to intubation or morality, death within 35 days were the secondary endpoints of the trial.
Data showed that treatment with SNG001 offered a 27% and 36% relative decline in the risk of progression to severe disease or mortality by 35 days, in the ITT and PP populations, respectively, versus placebo.
SNG001 was also found to have a favourable safety profile and was well tolerated in the trial subjects.
Synairgen CEO Richard Marsden said: “While we are disappointed by the overall outcome, SNG001 has been administered to hospitalised patients on top of standard of care which changed substantially between our Phase II and Phase III trials.
“Despite this, we have observed an encouraging trend in prevention of progression to severe disease and death, which we strongly believe merits further investigation in a platform trial.”
The company will assess the complete dataset from the trial to gain a better understanding of the detailed findings and implications for SNG001 development.
Currently, SNG001 is also being analysed to treat individuals with Covid-19 in the at-home setting in the ACTIV-2 trial of the US National Institute of Health.
In May last year, the company reported that data from the home cohort of Phase II SG016 trial of SNG001 showed a decline in hospitalisation rate in individuals with Covid-19.