Swiss company Relief Therapeutics Holding AG (SIX:RLF) (OTC:RLFTF) and its US partner, NeuroRx Inc, said on Wednesday that the US Food and Drug Administration (FDA) has granted an Expanded Access Protocol to RLF-100 (aviptadil) for treatment of respiratory failure in COVID-19.

RLF-100 is a synthetic form of Vasoactive Intestinal Peptide (VIP). It is currently in development by NeuroRx and Relief Therapeutics under Fast Track Designation and recently obtained positive safety opinion from the data monitoring committee.

The FDA protocol makes treatment available to patients who have exhausted standard therapies and are not eligible for the current phase 2/3 trial of RLF-100 because of confounding medical conditions. It specifically makes the treatment available to pregnant women.

Although the drug remains under investigation, Relief Therapeutics said that rapid recovery from respiratory failure in COVID-19 has been seen in patients treated under FDA Emergency Use Authorization.