TAR-200: Investigational intravesical drug delivery system for bladder cancer

Bladder cancer is second among the most common urothelial malignancy and one of the most expensive in terms of treatment. Localized bladder cancer is classified into non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC). First line approach for treatment of NMIBC is transurethral resection of bladder tumor (TURBT) followed by intravesical instillation of immuno/chemotherapeutic agents to prevent or delay recurrence or progression. Historically intravesical Bacillus Calmette Geurin (BCG) instillation has been a mainstay of therapy for NMIBC post-TURBT. Commonly followed drug delivery is intravesical instillation that maximizes exposure of the drug to the lesion and minimizes systemic side effects. Gemcitabine used in bladder cancer due to its pharmacological properties making it appropriate for intravesical instillation. Limitations of intravesical instillation is low bladder permeability leading to decreased drug concentration in bladder tissues and frequent urination causing drug wash out or dilution reducing the effect of treatment. Effective intravesical therapy depends on the penetration of the drug into the tumor. TAR200 is a novel drug delivery system that facilitates sustained release of continuous low dose gemcitabine over an indwelling period providing a uniform concentration of drug after each voiding cycle and exposure of drug to the bladder tumor. There are completed and ongoing clinical trials to evaluate the efficacy of TAR200 alone or in combination with other chemotherapeutic agents in NMIBC and MIBC. FDA has granted breakthrough therapy designation (BTD) for TAR-200 in December 2023. This review highlights the potential of TAR-200 and clinical trials that improve bladder cancer treatment outcome.