RedHill Biopharma has published positive results from a Phase II clinical trial which evaluated its antiviral RHB-107 (upamostat) in non-hospitalised symptomatic patients with Covid-19.

In the randomised, multi-centre, double-blind, placebo-controlled, parallel-group trial published in the International Journal of Infectious Diseases, it was found that the once-daily orally administered investigational antiviral met the primary endpoint of tolerability and safety.

Despite the small number of subjects in each group where they received the treatment, the antiviral delivered promising results.

In addition, the patients quickly recovered from severe Covid-19 symptoms and a 100% reduction in hospitalisation was observed in the trial.

Redhill Biopharma medical director Terry Plasse said: “Showing both safety and efficacy signals in a highly convenient once-daily oral therapy positively positions investigational RHB-107 as a potentially very useful treatment for Covid-19 outpatients to reduce symptom severity, and prevent disease progression and hospitalisation.

“Given the growing awareness of the limitations of existing options for early treatment of Covid-19, it is vital that we do not stop our efforts to bring new options forward, especially those in which we have already observed broad-acting, host-directed, variant-agnostic abilities.”

In the Phase II trial, non-hospitalised symptomatic Covid-19 patients received RHB-107 and were assessed for safety and tolerability.

The trial provided evidence for dose selection and preliminary assessments of parameters to be used for evaluating efficacy in a Phase III study.

For the study, the company enrolled a total of 61 subjects who were randomised on a 1:1:1 basis to receive one of two RHB-107 dose levels or a placebo control.

The trial results demonstrated a 100% reduction in hospitalisation, with zero patients in the RHB-107 arms versus 15% hospitalised in the placebo-controlled arm.

An 88% reduction was also observed in reported new severe symptoms of Covid-19 after initiating the treatment.

Only 2.4% of the RHB-107 treated group, against 20% of subjects in the placebo-controlled arm, reported new severe symptoms.

In March last year, Redhill Biopharma reported positive results from the Phase II part of the Phase II/III trial of RHB-107 in non-hospitalised symptomatic Covid-19 patients.