Eli Lilly published chemical series of RXFP1 (relaxin receptor 1) agonists mapped to potential indications including pulmonary hypertension, kidney disease and diabetic nephropathy. The disclosure presents small‑molecule agonists and in vitro activity supporting RXFP1 engagement, positioning a relaxin‑receptor axis as a target for cardiorenal and fibrotic disorders. Lilly’s filing signals sustained interest by big pharma in peptide/mimetic pathways now pursued with small molecules, underlining an industry push to convert biologically validated receptors into orally bioavailable therapeutics. ‘‘RXFP1 agonist’’ denotes a compound that activates the relaxin receptor to mimic relaxin peptide signaling.