This is an open-label, single-center pilot study designed to evaluate the safety, tolerability, and preliminary efficacy of TRG-200 KIT, an intravesical sustained-release oxybutynin formulation, in adult patients with refractory overactive bladder (OAB). The study includes an adaptive two-stage design with initial dose evaluation of two dose levels (150 mg and 300 mg oxybutynin) followed by expansion using the selected dose. TRG-200 KIT is administered via monthly intravesical instillation and aims to provide prolonged local bladder exposure while minimizing systemic absorption and anticholinergic adverse effects.
Willing and able to provide written informed consent and comply with all study procedures.
Male or female adults aged 18 years or older.
Documented diagnosis of overactive bladder (OAB) for more than 6 months, refractory or intolerant to oral anticholinergic or other OAB therapies.
Ability to perform and tolerate urethral catheterization for intravesical instillation.
Pregnant or breastfeeding women, or women of childbearing potential not using acceptable contraception.
Known contraindication, hypersensitivity, or allergy to oxybutynin or other anticholinergic agents.
History of 24-hour urine volume >3,000 mL.
Active urinary tract infection or genitourinary infection at screening (re-screening allowed once after treatment).