Volenrelaxin (LY3540378) increases renal plasma flow: a randomized Phase 1 trial

Background Volenrelaxin is a half-life-extended recombinant human relaxin protein developed for improving kidney perfusion and cardiorenal function. This study assessed the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of volenrelaxin following single- and multiple-ascending doses (SAD and MAD) administration. Methods In this Phase 1, four-part, randomized, double-blinded, placebo-controlled SAD and MAD study in healthy participants, SAD participants (n = 56) received an intravenous or subcutaneous dose of volenrelaxin or placebo in a dose-ascending manner. MAD participants (n = 77) received volenrelaxin or placebo subcutaneously once weekly for 5 weeks. Effective renal plasma flow (ERPF) and measured glomerular filtration rate (mGFR) were determined by para-aminohippurate and iohexol clearance, respectively. Results Volenrelaxin demonstrated an extended half-life and increased acute and chronic placebo-adjusted ERPF change from baseline by 50% and 44%, respectively (P < .0001). mGFR was unchanged, while filtration fraction and afferent/efferent renal arteriolar resistances were reduced. Systolic and diastolic blood pressures decreased, and pulse rate increased with increasing volenrelaxin exposures, demonstrating maximal model-derived placebo-adjusted changes (90% confidence interval) of –6.16 (–8.04, –4.28) mmHg, –6.10 (–7.61, –4.58) mmHg and +4.39 (+3.38, +5.39) bpm, respectively. Adverse events were mild, with no difference in orthostatic hypotension between volenrelaxin and placebo. Conclusion Volenrelaxin was well-tolerated, safe and suitable for weekly subcutaneous dosing. Volenrelaxin showed a sustained improvement in kidney perfusion upon repeated dosing, supporting further clinical development in chronic kidney disease and chronic heart failure. Clinical trial registration NCT04768855.