NRx Pharmaceuticals has reported that its therapy, Zyesami (aviptadil), demonstrated safety in the Phase III ACTIV-3b Critical Care clinical trial.

Sponsored by the US National Institutes of Health (NIH), the placebo-controlled, randomised trial is analysing Zyesami as a monotherapy or in combination with remdesivir (Veklury) in hospitalised Covid-19 patients with acute respiratory failure.

These subjects also need high-flow additional oxygen offered through a nasal cannula, mechanical ventilation or extracorporeal membrane oxygenation.

On analysing data from 348 subjects as part of the third assessment, the Independent Data Safety Monitoring Board (DSMB) of the trial found no new safety issues and recommended the continuation of participant enrolment.

According to the trial leadership, the enrolment has remained stable and the increase in cases due to the Delta variant does not appear to be subsiding.

Most of the subjects enrolled in the trial are unvaccinated, the company noted, adding that the trial has a target enrolment of 640 patients.

The NIH anticipates enrolling the first participant in the trial in February next year.

NRx Pharmaceuticals chairman and CEO professor Jonathan Javitt said: “It is promising to see the number of patients in this study increase while the safety analysis by the NIH continues to show Zyesami is safe to administer to patients with critical Covid-19, who have no other therapeutic alternative.

“We now have safety data on more than 600 patients treated with Zyesami in the ICU or step-down unit, with no reports of unexpected, drug-related, serious adverse events.”

This September, the company reported top-line data from a study where Zyesami boosted survival outcomes at one year in highly comorbid individuals with Covid-19.