Drug company NeuroRx Inc and Relief Therapeutics Holdings AG (SIX:RLF) (OTC:RLFTF) disclosed on Sunday that RLF-100 (aviptadil) showed rapid recovery from respiratory failure in the most critically ill patients with COVID-19, as well as blocked replication of the SARS coronavirus in human lung cells and monocytes.

The company added that RLF-100 is being developed as a Material Threat Medical Countermeasure in cooperation with the National Institutes of Health and other federal agencies. RLF-100 (aviptadil) is a patented formulation of Vasoactive Intestinal Polypeptide (VIP), which is known to be highly concentrated in the lungs and to inhibit a variety of inflammatory cytokines.

Additionally, patients with Critical COVID-19 were seen to have a rapid clearing of classic pneumonitis findings on x-ray, accompanied by an improvement in blood oxygen and a 50% or greater average decrease in laboratory markers associated with COVID-19 inflammation. The clinical findings may be based on evidence that VIP inhibits the replication of the SARS-CoV-2 virus in human lung cells and immune cells (monocytes). The work was reported by Brazilian researchers working in a level-4 biocontainment laboratory.

According to the company, there is evidence of early viral infection of the alveolar type 2 cells that are known to have angiotensin converting enzyme 2 (ACE2) receptors at high levels, which serve as the route of entry for the SARS-CoV-2 into the cells. The type 2 alveolar cells have high concentrations of VIP receptors on their cell surfaces giving rise to the hypothesis that VIP could specifically protect these cells from injury.