NeuroRx has reported that the Phase IIb/III trial of intravenously administered Zyesami (aviptadil acetate) for treating respiratory failure in critically ill Covid-19 patients met the primary endpoint.

A synthetic form of human vasoactive intestinal polypeptide (VIP), Zyesami is being developed in partnership with Relief Therapeutics.

The randomised, double-blind, multi-centre, placebo-controlled trial enrolled 196 participants at ten US hospitals.

According to the latest 60-day results, Zyesami met the primary endpoint of successful recovery from respiratory failure at day 28 in all subjects and showed a meaningful survival benefit after controlling for ventilation status and treatment site.

Clinically and statistically significant recovery from respiratory failure was observed in prespecified analysis in the 127 subjects treated with high flow nasal cannula (HFNC) versus those treated with mechanical or non-invasive ventilation at tertiary care hospitals.

In this group, subjects receiving Zyesami had a 71% chance of successful recovery by day 28 versus 48% in the placebo group. By day 60, the Zyesami group had a 75% rate of successful recovery versus 55% in the placebo group.

Furthermore, 84% of HFNC patients at tertiary medical centres receiving Zyesami survived to day 60 versus 60% receiving placebo.

Based on the latest data, NeuroRx intends to submit an application for Emergency Use Authorization (EUA) to the US Food and Drug Administration (FDA) and a New Drug Application (NDA), consequently.

NeuroRx chairman and CEO professor Jonathan Javitt said: “Zyesami has now demonstrated itself in a Phase II/III trial, conducted under FDA Fast Track Designation, not only to shorten hospitalisation (as was previously reported) but also to save lives and increase the likelihood of patients returning safely home to their families.

“In exactly 12 months, a lifesaving drug has advanced from concept to clinical success in partnership with Relief Therapeutics in the midst of a public health emergency that has claimed the lives of millions.”