Gemcitabine chemoablation for low-grade bladder cancer

COBRA - Chemoablation for Low Grade Bladder Cancer: A Single Arm, Prospective, Open-label, Investigator-initiated Phase 2 Study

Phase 2 Interventional Medical University of Vienna · NCT07019220

This study will try weekly bladder instillations of the chemotherapy drug gemcitabine to remove or control small, low-grade (Ta) bladder tumors in adults.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment47 (estimated)
Ages18 Years and up
SexAll
SponsorMedical University of Vienna Academic / other
Locations1 site (Vienna)
Trial IDNCT07019220 on ClinicalTrials.gov

What this trial studies

This is a single-arm, prospective, open-label Phase 2 study that gives six weekly intravesical instillations of gemcitabine to adults with histologically confirmed Ta low-grade bladder cancer. Eligible participants may have up to five tumors with the largest lesion ≤15 mm and must have negative cytology for high-grade disease and no metastases. The protocol collects cystoscopic and cytologic outcomes to measure local tumor response and monitors safety and tolerability throughout follow-up. The approach aims to determine whether chemoablation can clear or control small low-grade lesions and potentially reduce the need for transurethral resection.

Who should consider this trial

Good fit: Adults (≥18) with histologically confirmed recurrent or primary Ta low-grade bladder cancer, up to five lesions with the largest ≤15 mm, negative high-grade cytology, and no lymph node or distant metastasis are the intended participants.

Not a fit: Patients with high-grade or muscle-invasive disease, more than five lesions, tumors larger than 15 mm, positive cytology for high-grade disease, or evidence of nodal or distant metastases are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, intravesical gemcitabine chemoablation could clear small low-grade bladder tumors without surgery, reducing procedural risks and recovery time.

How similar studies have performed: Smaller and observational studies of intravesical gemcitabine and chemoablation strategies have shown promising but not definitive results for low-grade non–muscle-invasive bladder cancer.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Male/female participants who are at least 18 years of age on the day of providing documented informed consent will be enrolled in this study
* Diagnosis of a recurrent tumor and a history of TaLG BCa or diagnosis of primary TaLG BCa histologically confirmed by cold cup biopsy at screening or within 8 weeks before screening
* On screening cystoscopy: Diameter of the largest lesion ≤15mm
* Number of lesions ≤5
* Cystoscopy with bladder diagram including number, site, size and appearance of the tumors with photo documentation
* Patient who has recurrence of and not other than TaLG NMIBC (low or intermediate EAU risk)
* NMIBC requiring treatment with transurethral resection of bladder tumors (TURBT)
* Negative voiding cytology for high grade (HG) disease within 8 weeks before Screening
* No lymph node metastasis or distant metastasis
* Male and female patients must use an effective contraceptive method during the study and for a minimum of 6 months after study treatment
* Female patients of childbearing potential must have a negative serum pregnancy test within 2 weeks prior to enrollment. Female patients of childbearing potential must use adequate contraception during study period
* Willing and able to provide informed consent

Exclusion Criteria:

* Tumors that clinicians suspect to be HG
* Positive HG cytology according to Paris criteria
* Diameter of tumor \>15 mm
* Number of lesions \>5
* Any previous intravesical therapy within 1 year
* Previous HG NMIBC (within the last 3 years). It is allowed to include patients who had history of HG disease longer than 3 years ago.
* Past or current muscle invasive bladder cancer (i.e., T2, T3, T4) or metastatic UC
* History of upper tract urothelial carcinoma (UTUC)
* Clinically significant urethral stricture that would preclude passage of a urethral catheter
* History of neurogenic bladder; active urinary retention; any other condition that would prohibit normal voiding
* Evidence of active urinary tract infection (UTI) that in the Investigator's opinion cannot be treated and resolved prior to biopsy and/or administration of study treatment
* Patient refused to participate
* Known positive human immunodeficiency virus (HIV) test.
* Female patients who are pregnant/breastfeeding.
* Female patients of childbearing potential not using adequate contraception.

Where this trial is running

Vienna

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bladder CancerNon-Muscle Invasive Bladder CancerIntravesical TherapyNon-Surgical Treatment
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.