A Single-Arm, Dose Escalation of an Intraurethral Alprostadil Paste for Erectile Dysfunction

This is a single arm dose escalation trial of a mucoadhesive intraurethral polymer suspension of alprostadil (ST-04) and will investigate the efficacy of 3 dose levels of ST-04 in adult males with a clinical diagnosis of Erectile Dysfunction (ED). This study aims to determine if ST-04, with or without sildenafil, will improve erectile function (EF) compared to baseline. Participants in this study will receive ST-04, a new formulation containing the vasodilator, alprostadil which is known to be an effective drug in treating erectile dysfunction. ST-04 will be dispersed along the urethra, forming a hydrogel which adheres to the lining of the urethra with the goal of penile tumescence and erection. Participants may receive up to 3 dose level escalations of ST-04 over a 12-week period, for a total of up to 11 administrations of ST-04. Dose escalation may also be done with and without sildenafil.

NCT Number	NCT07601646
Lead Sponsor	Ryan Flannigan, MD
Conditions	Erectile Dysfunction (ED), Erectile Dysfunctions, Erectile Function
Enrollment	83 participants
Start Date	2026-05
Primary Completion	2027-04 (estimated)
Study Completion	2027-05 (estimated)
Updated on ClinicalTrials.gov	2026-05-22