ST-04 for erectile dysfunction uses the instillation of a patent-protected ST mucoadhesive formulation with alprostadil into the urethra to deliver active drug via transurethral absorption. The approach provides excellent local pk/pd, avoids systemic delivery, and is intended to result in fewer side effects. A Phase II trial is projected to start in Q1 2026. The program is progressing through rapid clinical development, follows a 505(b)(2) regulatory pathway with low development risk, and has high partnering potential.