A Phase 2 interventional study of ST-04 in Erectile Dysfunction (ED), Erectile Dysfunctions and Erectile Function, sponsored by Ryan Flannigan, MD. Recruiting at 1 site in Canada. Open to male participants aged 21 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-05-22.
Sponsored by Ryan Flannigan, MD · Phase 2, Interventional, and Treatment
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.
701 studies on the registry are indexed under Erectile Dysfunction; 125 are open to participants now.
This study's planned enrollment of 83 is above the median of 70 across 551 interventional studies indexed under Erectile Dysfunction.
Browse Erectile Dysfunction studies →This is the only study on the registry with Ryan Flannigan, MD as lead sponsor.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dose Level 1 is 500 μg of ST-04; Dose Level 2 is 1000 μg of ST-04 with or without Sildenafil; Dose Level 3 is 1500 μg of ST-04 with or without Sildenafil.
Drug: ST-04
ST-04 consists of an alprostadil polymer suspension designed for intraurethral application
Change from Baseline in the Erectile Function Domain of the IIEF Questionnaire
The IIEF is a validated questionnaire assessing erectile function, with total scores ranging from 5 to 25; higher scores indicate better erectile function
Time frame: From baseline to 1 month after start of the last dose level (Week 4, 8, 12 respectively)
Change from Baseline in the Erectile Hardness Scale (EHS)
The EHS is a self-reported assessment of penile hardness on a scale of 0 (no engorgement) to 4 (complete rigidity).
Time frame: From baseline to the end of treatment at week 4, 8 or 12 respectively
Change from Baseline in the Sexual Encounter Profile (SEP)
SEP is a log diary completed after each sexual attempt, providing information as to whether the erection was hard enough to penetrate (SEP 2), or whether it was maintained for completion (SEP 3).
Time frame: From baseline to the end of treatment at week 4, 8 or 12 respectively
Percentage of Uses per Participant of ST-04 which Led to the Onset of Erection within up to 30 minutes of Application per Number of Intercourse Attempts
Percentage of participants using ST-04 that could achieve an erection and/or penetrative intercourse within 30 minutes of application per number of intercourse attempts.
Time frame: From baseline to the end of treatment at week 4, 8 or 12 respectively
Incidence and Severity of Adverse events
Adverse events will be recorded at each follow-up visit and classified by type, severity, and relationship to the intervention.
Time frame: From baseline to the end of treatment at week 4, 8 or 12 respectively
Start is estimated for May 2026; primary completion for Apr 2027, 11 months later.
Of 24 phase 2 interventional studies under Erectile Dysfunction, half reached primary completion within 28 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 32. This study's planned 11 months is below that.
How these figures are worked out, and which studies are left out of them.
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