A groundbreaking new device, informally dubbed the “pretzel-shaped” implant, is revolutionizing the treatment landscape for high-risk, non-muscle-invasive bladder cancer (NMIBC). Clinical trial results show that this novel slow-release system, called TAR-200, has achieved an impressive complete response rate in patients for whom other treatments had failed. This technology offers a significant, bladder-sparing alternative to the life-altering surgery of cystectomy.
The TAR-200 Device and Its Mechanism
The TAR-200 is a small, intravesical device designed to be inserted into the bladder through a simple catheter procedure. Once inside, its unique pretzel shape allows it to remain in place without being expelled during urination. The device continuously releases the chemotherapy drug gemcitabine directly to the bladder lining over a period of three weeks.
This method marks a major advancement in drug delivery. Historically, gemcitabine has been administered as a liquid solution that stays in the bladder for only a few hours. The sustained release provided by the TAR-200 allows for much longer contact time, enabling the drug to penetrate more deeply into the bladder wall and kill cancer cells more effectively. This localized delivery also keeps systemic drug exposure low, which helps minimize side effects.
In-Depth Look at the SunRISe-1 Clinical Trial
The promising results come from the Phase 2 SunRISe-1 trial, a global, multicenter study. The trial focused on patients with high-risk NMIBC who had not responded to the standard-of-care immunotherapy, Bacillus Calmette–Guérin (BCG). These patients typically have very limited treatment options.
In the monotherapy cohort, the TAR-200 device alone produced an 82.4% complete response rate at the three-month mark. For many of these patients, the response proved durable, with almost half remaining cancer-free a year later. A parallel arm of the trial, which combined TAR-200 with the monoclonal antibody cetrelimab, did not show improved complete responses and was associated with more side effects, suggesting that the device alone is the most effective approach.
The trial also showed that the treatment was well-tolerated. Common side effects included dysuria (painful urination) and urinary tract infections, which were manageable. There were no treatment-related deaths reported.
Other Developments and Future Outlook
The success of TAR-200 is part of a broader effort to create targeted drug delivery systems for bladder cancer. Another device, TAR-210, is built on the same platform but delivers a different targeted therapy, erdafitinib, to patients whose tumors have a specific FGFR gene alteration. This highlights the potential for personalized, in-bladder treatments that target the unique genetic makeup of a patient’s cancer.
With the U.S. Food and Drug Administration (FDA) granting TAR-200 a new drug application Priority Review, it is a step closer to becoming a viable treatment option for patients who previously faced a difficult choice between ineffective treatments and radical surgery. Researchers are hopeful that this technology could transform the standard of care, offering a new path to lasting remission for many.
References
- Moffitt Cancer Center. “Novel Drug Delivery System, TAR-210 Clinical Study, for Bladder Cancer.” [URL: https://www.moffitt.org/newsroom/press-release/2025/novel-drug-delivery-system-tar-210-clinical-study-for-bladder-cancer/]
- ScienceBlog.com. “Slow-Release Chemo Device Clears Most Bladder Tumors in Key Trial.” [URL: https://scienceblog.com/slow-release-chemo-device-clears-most-bladder-tumors-in-key-trial/]
- Keck Medicine of USC. “New treatment eliminates bladder cancer in 82% of patients.” [URL: https://news.keckmedicine.org/new-treatment-eliminates-bladder-cancer-in-82-of-patients/]
- The ASCO Post. “New Drug-Releasing System Eliminates Bladder Cancer in Over 80% of Patients in a Phase II Trial.” [URL: https://ascopost.com/news/august-2025/new-drug-releasing-system-eliminates-bladder-cancer-in-over-80-of-patients-in-a-phase-ii-trial/]
- Technology Networks. “TAR-200 Eliminates Tumors in 82% of High-Risk Bladder Cancer Patients.” [URL: https://www.technologynetworks.com/cancer-research/news/tar-200-eliminates-tumors-in-82-of-high-risk-bladder-cancer-patients-378396]
- UroToday. “Intravesical Therapy with a TAR-200 Gem-stuffed Pretzel.” [URL: https://www.urotoday.com/conference-videos/asco-2025/intravesical-therapy-with-a-tar-200-gem-stuffed-pretzel.html]
