Intravesical chemotherapy device shows promise in muscle-invasive bladder cancer

A new intravesical chemotherapy delivery system called TAR-200 was found to be safe and tolerable for patients with muscle-invasive bladder cancer (MIBC) who refused or were unfit for curative-intent therapy, according to findings from a phase 1 study (NCT03404791). The data were published in the Journal of Urology.^1,2

Progression-free rate was 92.3% at 6 months and 70.5% at 12 months among the 14 patients with lasting responses to the treatment.

TAR-200 works by providing continuous low-doses of localized gemcitabine via insertion into the bladder. The phase 1 TAR-200-103 study assessed the feasibility of the device in patients with advanced bladder cancer.

"Our preliminary clinical trial found that TAR-200 was generally safe, well tolerated, and had beneficial effects on bladder cancer outcomes in a group of patients with limited treatment options," said lead author Mark Tyson, MD, MPH, in a news release on the findings.² Tyson is a urologic oncologist at Mayo Clinic in Phoenix, Arizona.

The multicenter, open-label, single-arm study enrolled 35 patients who had cT2-cT3bN0M0 urothelial carcinoma. Median age among the participants was 84 years, and 68.6% were male. Patients received therapy with TAR-200 for up to 84 days, broken up into 4 21-day cycles. Primary end points of the study were safety and tolerability.

In regard to safety, 15 patients had treatment-emergent adverse events (TEAEs) related to TAR-200, and 2 patients had TEAEs that led to removal of the device. The most common TEAEs were dysuria and urinary frequency. In total, 1 patient had a TEAE that led to treatment discontinuation.

At 3-month follow-up, the complete response rate was 31.4% (11 patients) and the partial response rate was 8.6% (3 patients), which yielded an overall response rate of 40%. Median overall survival was 27.3 months, and the duration of response was 14 months.

Progression-free rate was 92.3% at 6 months and 70.5% at 12 months among the 14 patients with lasting responses to the treatment. Median time to disease progression was 13.5 months and median progression-free survival was 9.5 months.

"Overall, the observed clinical response to TAR-200 was robust and durable in a cohort with very limited curative-intent treatment options,” said the authors, indicating that the results warrant further study of the device.

Currently, TAR-200 is being assessed in combination with the systemic inhibitor of programmed cell death protein-1 cetrelimab in the SunRISe clinical trial program (NCT04640623, NCT04658862, NCT04919512).

References

1. Tyson MD, Morris D, Palou J, et al. Safety, tolerability, and preliminary efficacy of TAR-200 in patients with muscle-invasive bladder cancer who refused or were unfit for curative-intent therapy: a phase 1 study. Journal of Urology. Published online April 7, 2023. Accessed April 10, 2023. doi:10.1097/JU.0000000000003195.

2. Sustained-release chemotherapy gives new options for frail patients with invasive bladder cancer. News release. Wolters Kluwer Health: Lippincott. April 7, 2023. Accessed April 10, 2023. https://www.newswise.com/articles/sustained-release-chemotherapy-gives-new-option-for-frail-patients-with-invasive-bladder-cancer?sc=mwhr&xy=10016681