NeuroRx and Relief Therapeutics said that RLF-100 (aviptadil) delivered quick recovery from respiratory failure in the most critically ill patients suffering from Covid-19 in a phase 2/3 clinical trial.

The companies said that rapid recovery was seen in patients on ventilators and extracorporeal membrane oxygenation (ECMO) and having severe medical comorbidities following three days of treatment with RLF-100 at various clinical sites.

RLF-100 is being developed as the first therapeutic for Covid-19 for preventing replication of the SARS-CoV-2 virus in human lung cells and monocytes, as reported by independent researchers.

A patented formulation of synthetic human vasoactive intestinal polypeptide (VIP), the drug candidate has the fast track designation, emergency use IND authorisation, and an expanded access protocol from the US Food and Drug Administration (FDA).

The Covid-19 drug candidate is being developed as a material threat medical countermeasure in cooperation with the National Institutes of Health and other federal bodies with more research to be carried out.

NeuroRx CEO and chairman Jonathan Javitt said: “No other antiviral agent has demonstrated rapid recovery from viral infection and demonstrated laboratory inhibition of viral replication.

“We are conducting placebo-controlled trials to see whether the observations made in the case-control and open-label studies will be confirmed for less ill patients with COVID-19-related respiratory failure. Our independent Data Monitoring Committee will be conducting an interim analysis of these data later this month.”

According to NeuroRx, vasoactive intestinal polypeptide uniquely binds to receptors on Alveolar Type II cells in the lung, which are the same cells that hold together the SARS-CoV-2 virus through their ACE2 receptors. By preventing cytokines, stopping apoptosis, and upregulating the production of surfactant, vasoactive intestinal polypeptide safeguards the cells and the nearby pulmonary epithelium, said the company.

Relief Therapeutics, which is based in Switzerland, has been partnering with NeuroRx for carrying out two phase 2b/3 clinical trials to determine the efficacy of RLF-100 in patients having severe or moderate Covid-19 induced acute respiratory distress syndrome (ARDS).