NeuroRx has reported that preliminary results from its Phase IIb/III trial of Zyesami (aviptadil, formerly RLF-100) showed it reduced hospital stay among patients with respiratory failure due to critical Covid-19.

Zyesami is a synthetic form of human Vasoactive Intestinal Peptide (VIP).

The study was carried out in partnership with Relief Therapeutics and had 203 patients. Of these, 136 received Zyesami, while 67 received the standard of care (SOC).

All trial participants were analysed through day 28 with planned long-term follow-up through day 60.

Results showed that the patients receiving maximal SOC plus Zyesami were discharged sooner from the hospital versus those receiving placebo plus maximal SOC.

NeuroRx noted that Zyesami would be the first drug indicated for critically ill Covid-19 patients with respiratory failure, if authorised for use.

NeuroRx CEO Jonathan Javitt said: “We are greatly encouraged by these preliminary findings and believe they are indicative of a biologic effect of aviptadil in hastening recovery from critical Covid-19.

“We expect to discuss with the Food and Drug Administration and other regulatory authorities the submission of an Emergency Use Authorisation (EUA) so that Zyesami can be available for treating this population that is at immediate risk of death and for which there is no approved therapy.”

Conducted in ten medical centres, the trial showed that the drug was safe when administered by intravenous infusion in the ICU.

In the secondary efficacy endpoints analysed in patients treated with High Flow Nasal Cannula (HFNC) therapy and with Mechanical Ventilation, Zyesami demonstrated an advantage in 15 of 16 comparisons and showed a 40% or better advantage.

The company noted that this difference includes at least a five-day median reduction in the hospital stay.

Furthermore, the largest difference noted was among those treated with HFNC who experienced a median of 11 fewer days in the hospital.

Last week, NeuroRx initiated a Phase II/III clinical trial of its inhaled Zyesami for treating patients with severe Covid-19.