Relief Therapeutics and NeuroRx have applied to the FDA for an Emergency Use Authorization (EUA) for RLF-100 (aviptadil) for the treatment of critical COVID-19 patients with respiratory failure.

Aviptadil is a synthetic form of a natural peptide that blocks replication of the SARS-CoV-2 coronavirus in human lung cells and immune cells. The agency previously granted aviptadil an Orphan Drug designation for treatment of acute respiratory distress syndrome.

The EUA application was based on a study of 51 patients, in which those treated with aviptadil demonstrated a three-fold increase in survival, recovery from respiratory failure and improvement in other clinical measures compared to those receiving the standard of care.

The emergency use request targets the same critically ill population that the FDA allowed to receive the drug under an expanded access protocol.