A Proof-Of-Concept (POC) Study of SFG-02 Transdermal Formulation in Participants With Underactive Bladder (UAB)

The objective of this POC (Phase 2a) study is to evaluate the effect on Bladder Voiding Efficiency (BVE) as well as safety of SFG-02 transdermal formulation in participants with UAB. Participants will: * Apply the study patches every day for 12 weeks and wear each patch for a full day * Visit the clinic once every 2 to 4 weeks for checkups and tests * Keep diaries about their bladder symptoms and the times they change their study patches

Inclusion Criteria: * Participants must have at least 2 out of 3 symptoms of UAB (urinary hesitancy, straining to void, and/or weak urinary stream) for at least 3 months before entering the study * Participants must meet the criteria for the study based on uroflowmetry assessments, ultrasound scans of the bladder, and a urodynamics study assessment at study entry * If the participant uses clean intermittent self-catheterization (CISC), the participant must have been using CISC continuously for at least 3 months, and must not be completely dependent on CISC to empty their bladder * Participants must have adequate kidney, liver, and heart function based on laboratory blood tests and electrocardiograms Exclusion Criteria: * Participants with clinically significant obstructions of lower urinary tract * Participants with an upper or lower urinary tract infection, or a genital infection * Participants with one or more bladder diverticula or any other condition that may affect the measurement of post-void residual (PVR) urine volume * Participants with calculi (stones) in the ureter, bladder, or urethra * Participants with vesicoureteral and/or renal reflux * Participants with hydronephrosis * Participants with an indwelling urinary catheter * Participants who rely on voiding assistance maneuvers to facilitate urination * Participants with moderate-to-severe overactive bladder, defined by an OABSS, or participants with overactive bladder requiring treatment * Participants with a low-compliance bladder * Participants who are currently taking medications for voiding dysfunction * Participants with increased pelvic floor muscle activity during voiding * Participants with a history of bladder surgery * Participants who have undergone surgery for urethral obstruction due to Benign Prostatic Hyperplasia (BPH) or for pelvic organ prolapse within the past 6 months * Participants who have undergone surgery for urinary incontinence or any other pelvic surgery within the past 12 months * Participants with chronic pelvic pain that may affect uroflowmetry results * Participants with a history of pelvic radiation therapy * Participants with overflow urinary incontinence