Appili Therapeutics has expanded the Phase III clinical trial of Avigan/Reeqonus (favipiravir) with the addition of multiple clinical research centres in Mexico and Brazil to treat mild to moderate Covid-19.

Developed by FUJIFILM Toyama Chemical, Avigan is a broad-spectrum oral antiviral approved in Japan for influenza treatment.

The drug selectively hinders viral ribonucleic acid (RNA)-dependent RNA polymerase (RdRP) with strong antiviral activity against single-stranded RNA viruses, such as coronaviruses.

Named PRESECO, the Phase III trial is assessing the safety and efficacy of Avigan as a home-based treatment option for mild-to-moderate Covid-19.

The primary aim of the trial is a substantial reduction in time to a sustained recovery in participants who receive Avigan versus placebo.

More than 730 subjects have so far been enrolled in the US trial, which initiated dosing in December last year.

Appili noted that the latest expansion into Mexico and Brazil will aid in concluding the trial on time and establish favipiravir as an oral Covid-19 antiviral candidate.

Site activation is progressing in Mexico while some centres are open and currently enrolling study participants. In Brazil, site activation is anticipated to commence soon.

Top-line data from the Phase III trial is expected to be available in September this year.

Appili Therapeutics chief medical officer Yoav Golan said: “With cases decreasing in the US our clinical expansion into Brazil and Mexico will help us meet our enrolment goal.

“With this expansion of our trial, we will be able to move quicker towards our goal of determining whether Avigan/Reeqonus is effective in helping people who suffer from mild-to-moderate Covid-19 to recover faster and avoid hospitalisation and death.”

An independent Data and Safety Monitoring Board recently advised continuing the PRESECO study without any changes.

As part of this trial expansion, Appili has stopped its Phase II CONTROL trial of Avigan for Covid-19 treatment in long-term care settings.

Furthermore, Appili intends to launch a Phase III PEPCO study of Avigan to prevent Covid-19 in asymptomatic people who were directly exposed to an infected individual.

The company expects to start enrolment in PEPCO study in the second half of this year, after concluding PRESECO.