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

Phase 2 Clinical Trial of ST-04 Intraurethral 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.

Inclusion Criteria:

• Have had a confirmed clinical diagnosis of ED for more than three months based upon IIEF
• Have failed PDE5 inhibitor therapy (inability to achieve an erection with adequate rigidity to allow penetrative sex)
• Ability to take oral medication (sildenafil) and be willing to adhere to the study intervention regimen
• Engaged in heterosexual relationship with partner for a minimum of 6 months

Exclusion Criteria:

• History of unstable medical or psychiatric condition that, in the opinion of the principal investigator, could impact the patient's ability to complete the study investigations or protocol.
• Spinal cord injury, or penile anatomical abnormalities
• Cardiovascular conditions that prevent sexual activity (NYHA Class II or higher, any angina, or uncontrolled CHF or severe coronary artery disease)
• History of myocardial infarction, stroke, or life-threatening arrhythmia within 6 months prior to enrollment into the study
• Use of anti-androgens, or oral or injectable androgens
• Documented hypotension or known orthostatic hypotension
• Use of oral, topical or sublingual nitrates within 3 months prior to enrollment into the study
• Hepatic (Child-Pugh Class C) or renal failure (eGFR < 30)
• Inadequate response to intracavernosal injection therapy previously
• Peyronie's disease or Meatal stenosis