An open-label, uncontrolled dose-optimization study of sublingual apomorphine in erectile dysfunction

Area of Science:

• Pharmacology
• Urology
• Clinical Trials

Background:

• Apomorphine, a dopamine agonist, has been explored for erectile dysfunction (ED) due to its role in central nervous system pathways mediating erection.
• However, apomorphine can induce nausea via dopamine receptor stimulation in the brain's chemotrigger zone.
• A low, rapidly achieved plasma concentration may selectively target erectile response while minimizing nausea.

Purpose of the Study:

• To evaluate the efficacy and tolerability of a dose-optimized sublingual formulation of apomorphine (apomorphine SL) for treating erectile dysfunction (ED).

Main Methods:

• A multicenter, open-label, Phase III study involving 849 heterosexual men with ED.
• A 2-week screening period followed by a 3-week dose-optimization period (2-4 mg) and a 4-week treatment period.
• Efficacy assessed by the percentage of attempts resulting in erections firm enough for intercourse, using patient diaries.

Main Results:

• Mean percentage of attempts with erections firm enough for intercourse increased from 13.1% at baseline to 39.4% with optimal dosing.
• Successful intercourse attempts rose from 12.7% to 38.3%.
• Median time to erection was 23 minutes, and median duration was 13 minutes. Nausea occurred in 11.7% of patients.

Conclusions:

• A dose-optimized regimen of apomorphine SL, initiated at 2 mg and adjusted up to 4 mg, demonstrated effectiveness and good tolerability in treating ED.
• The treatment was effective regardless of the cause or severity of erectile dysfunction.