Relief Therapeutics and its partner NeuroRx have started patient enrolment and treatment in a Phase IIb/III clinical trial of RLF-100 to treat acute respiratory distress syndrome (ARDS) caused by Covid-19.

The first patients are being treated at the University of Miami Miller School of Medicine in Florida, US. The partners are recruiting patients on mechanical ventilation for the  trial.

RLF-100 is a formulation of a synthetic human vasoactive intestinal polypeptide (VIP) called Aviptadil, which acts on alveolar type 2 cells in the lungs.

Various animal models of lung injury and lung disease showed that VIP blocks inflammatory cytokines and protects pulmonary epithelial cells in the air sacs of the lungs.

NeuroRx CEO Jonathan Javitt said: “RLF-100 previously showed promising Phase I results in ARDS related to sepsis and promising Phase II results in the treatment of other inflammatory lung conditions.

“Aviptadil specifically binds to the cells in the lung that are essential to transmitting oxygen to the body and to making surfactant that is essential to oxygen exchange (the Alveolar Type II cells). These are the same cells that are targeted and killed by the SARS-CoV-2 virus.”

The multi-centre, randomised, placebo-controlled Phase IIb/III trial is set to enrol 120 participants, who will receive intravenous (IV) RLF-100 plus maximal intensive care or placebo with maximal intensive care.

The primary endpoints of the study will be mortality and index of respiratory distress, while secondary endpoint will include TNFa levels and multi-system organ failure free days.

Relief Therapeutics and NeuroRx are working to trial and boost access to RLF-100 in the EU, UK, Russia and Australia.

Last month, Relief Therapeutics announced that a Phase II trial of Aviptadil is being performed at New York University Langone (NYU Langone Health) for the treatment of Covid-19-related ARDS.