PL-3994 is a natriuretic peptide-A receptor agonist compound developed by Palatin Technologies for treatment of heart failure . PL-3994 has an extended half-life , with reduced affinity for natriuretic peptide clearance receptors and increased resistance to neutral endopeptidase , an endogenous enzyme that degrades natriuretic peptides . PL-3994 is being developed as a subcutaneously administered drug , and is well absorbed through this route of administration .