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In A Nutshell
- A new bladder cancer device called TAR-200 delivers chemotherapy directly into the bladder over time, avoiding long treatment sessions.
- In a clinical trial, over 8 in 10 patients with a specific type of bladder cancer (carcinoma in situ) saw their cancer disappear after treatment.
- Many patients stayed cancer-free for more than a year, and most were able to avoid bladder removal surgery during the study period.
- Side effects were mostly mild urinary symptoms that cleared up within weeks, with serious problems being uncommon.
LOS ANGELES — For bladder cancer patients whose tumors stop responding to standard treatment, the choice has often been daunting: undergo radical surgery to remove the entire bladder, or pursue alternative treatments that may not be as effective. Results from a clinical trial suggest a promising third option may be emerging, at least for some patients.
Researchers announced that an experimental treatment called TAR-200 helped 82.4% of patients with carcinoma in situ (CIS), an aggressive form of bladder cancer, become cancer-free without requiring bladder removal surgery. The results, published in the Journal of Clinical Oncology, represent the highest single-agent complete response rate reported to date for this patient group.
The study focused on patients with BCG-unresponsive high-risk non–muscle-invasive bladder cancer (NMIBC), a form of the disease where tumors no longer respond to BCG therapy, the current standard treatment that uses weakened tuberculosis bacteria to boost the immune system against cancer cells. While radical cystectomy remains the current standard of care for these patients, many are unable or unwilling to undergo the procedure. Other FDA-approved bladder-sparing treatments exist, but their response rates have historically been lower than the TAR-200 results seen in this study.
How TAR-200 Bladder Cancer Treatment Works
Other intravesical bladder cancer treatments typically require patients to retain the medication in their bladder for one to two hours after instillation. TAR-200 takes a different approach: it’s a first-in-class intravesical drug-releasing system designed to provide sustained delivery of the chemotherapy drug gemcitabine directly into the bladder over time.
The device is inserted during a brief office procedure. Once placed, it provides continuous local drug delivery and is replaced on a scheduled basis (every three weeks for the first six months, then every 12 weeks for up to two years).
Dr. Sia Daneshmand from the University of Southern California Norris Cancer Center and his colleagues tested TAR-200 in 85 patients with CIS whose bladder cancer had stopped responding to BCG treatment.
82% Complete Response in CIS Cohort
Among the 85 patients who received TAR-200 alone, 70 patients (or 82.4%) achieved complete remission, meaning no signs of cancer could be detected during follow-up examinations. Most patients saw their cancer disappear within about three months of starting treatment.
According to the researchers, TAR-200 monotherapy achieved the highest single-agent response rate reported to date in this setting, with rapid onset and sustained effectiveness.
The responses proved durable. The median time patients remained cancer-free was 25.8 months, with 53% of responding patients staying disease-free for at least a year. After two years, roughly three-quarters of patients had avoided bladder removal surgery entirely. Because the median follow-up for this group was 20.2 months, not all patients had reached two full years.
The treatment also showed promise for patients with high-risk papillary bladder tumors. In a separate group of 52 patients with this form of cancer, 70.2% remained disease-free at the one-year mark.
By comparison, current FDA-approved treatments for BCG-unresponsive bladder cancer typically achieve complete responses in about 41–62% of patients. However, the researchers also noted that a recent study of another investigational agent showed a 75% complete response rate — closer to the TAR-200 results.
Side Effects Remain Manageable
TAR-200 showed a favorable safety profile that could make it accessible to patients who might not tolerate more aggressive treatments. The most common side effects were mild urinary symptoms (frequent urination, burning during urination, and urgency) that typically resolved within three weeks.
Only 12.9% of patients experienced severe side effects, and just 3.5% stopped treatment due to adverse reactions. No treatment-related deaths occurred during the study period. Adverse event rates were higher in other trial cohorts. For example, in the combination therapy group, 26.4% discontinued TAR-200 and 24.5% discontinued cetrelimab because of treatment-related adverse events. No treatment-related deaths occurred in any group.
What This Means for Patients
The importance of these results becomes clear when considering the limited options currently available. Radical cystectomy, while potentially curative, carries substantial risks. The procedure has a 90-day mortality risk of around 5% for all patients, rising to about 15% in elderly patients.
Real-world data suggests that fewer than 20% of patients with this type of bladder cancer actually undergo the recommended surgery, often due to age, other health conditions, or personal preference. Many patients are left with few alternatives.
The research does have important limitations. As a single-arm study without a control group, the results cannot be directly compared to other treatments through randomized trials. The median follow-up for responders in the CIS monotherapy group was 20.2 months. The study population was primarily older, White males, which may limit how broadly the results apply to other patient groups. Cost-effectiveness was not evaluated.
Despite these limitations, TAR-200 is being tested in additional clinical trials, including studies comparing it directly to other treatments and examining its use in combination with immunotherapy drugs.
For eligible patients who have exhausted standard treatment options, TAR-200 offers the possibility of keeping their bladder while effectively treating their cancer, potentially transforming quality of life for many diagnosed with this aggressive disease. Innovations like TAR-200 point toward a future of more personalized, less invasive treatment approaches.
Disclaimer: This article is based on the results reflect a phase IIb, noncomparative clinical trial and should not be interpreted as definitive proof of TAR-200’s effectiveness compared to other treatments. Response rates, survival estimates, and cystectomy-free rates are specific to the study’s patient populations and time frames; ongoing randomized controlled trials will be needed to confirm these results. Patients should consult their healthcare providers to discuss individual treatment options.
Paper Summary
Methodology
Researchers conducted a phase IIb clinical trial called SunRISe-1, enrolling patients between March 2021 and April 2024 at 142 sites across 14 countries. The study included patients with BCG-unresponsive bladder cancer — meaning their tumors had stopped responding to standard BCG therapy after adequate treatment courses. Participants were divided into four groups:
- CIS patients received TAR-200 alone, TAR-200 plus the immunotherapy drug cetrelimab, or cetrelimab alone.
- Patients with high-risk papillary tumors received TAR-200 alone.
The main group analyzed included 85 CIS patients who received TAR-200 monotherapy. TAR-200 was administered every three weeks for six months, then every 12 weeks for up to two years. The primary endpoint was centrally confirmed complete response rate, determined through urine cytology, bladder examinations, and biopsies.
Results
In the CIS monotherapy group, TAR-200 achieved an 82.4% complete response rate, with most responses occurring within about three months. The median duration of response was 25.8 months, and 52.9% of responders maintained their response for at least 12 months. The 12- and 24-month radical cystectomy–free rates were estimated at 86.6% and 75.5%, respectively, based on Kaplan–Meier analysis. In the papillary cohort, the 12-month disease-free survival rate was 70.2%. Overall survival rates were high, with 94.7% of patients alive at 12 months. In the CIS monotherapy group, 3.5% discontinued due to treatment-related adverse events.
Limitations
As a noncomparative trial, the study cannot directly measure how TAR-200 stacks up against other therapies. The median follow-up for responders in the CIS monotherapy group was 20.2 months. Cohort sizes were modest, the population was primarily older white males, and cost-effectiveness was not assessed. Longer follow-up and randomized controlled trials will be needed to confirm these findings.
Funding and Disclosures
The study was sponsored by Janssen Research & Development, LLC, a Johnson & Johnson company. Many authors reported financial relationships with various pharmaceutical companies, including consulting fees, research funding, and stock ownership. Several authors were employees of Johnson & Johnson. Lead author Dr. Siamak Daneshmand reported relationships with multiple companies including Janssen, and disclosed stock ownership in Taris, a company involved in TAR-200 development.
Publication Information
Published in the Journal of Clinical Oncology on July 30, 2025, as an accepted unedited manuscript. Citation: Daneshmand S, Van der Heijden MS, Jacob JM, et al. TAR-200 for Bacillus Calmette-Guérin–Unresponsive High-Risk Non–Muscle-Invasive Bladder Cancer: Results From the Phase IIb SunRISe-1 Study. J Clin Oncol. DOI: 10.1200/JCO-25-01651. ClinicalTrials.gov number: NCT04640623.
