NRx Pharmaceuticals, Inc. announced that the US Food and Drug Administration (FDA) has declined to issue an Emergency Use Authorization (EUA) for ZYESAMI® (aviptadil) for a sub-group of patients that in addition to ZYESAMI®, also received Remdesivir and continued to progress.  NRx Pharmaceuticals had submitted this last EUA application using data from a post-hoc subgroup analysis.