Dutasteride in Patients With Low Grade Non-muscle Invasive Bladder Cancer (DutaBCa-1)

A Phase II Prospective Single-arm Study of Dutasteride in Patients With Low Grade Non-muscle Invasive Bladder Cancer

Low grade non-muscle-invasive bladder cancer (NMIBC) often recurs after treatment, requiring repeated surgeries, especially in older patients. These recurrences can cause complications, reduce quality of life, and increase healthcare costs. Currently, there is no well-tolerated preventive treatment routinely used for patients with low-risk disease.

This study will evaluate whether dutasteride, an oral medication that blocks androgen activity, can reduce the risk of bladder cancer recurrence. Dutasteride is generally well tolerated and easy to take. The study will also assess its safety in women.

The goal of this study is to determine whether dutasteride can provide a simple and effective way to prevent recurrences of low grade non-muscle invasive bladder cancer.

Study Overview

• Status: Recruiting
• Conditions: Bladder Cancer
• Intervention / Treatment: Drug: Dutasteride (0.5mg)

Detailed Description

The study will therefore include two separate cohorts of men (n=70) and women (n=25).

After the screening phase, eligible male and female patients who provide informed consent will receive dutasteride at a dose of 0.5 mg once daily for the duration of the study. All participants will follow the same treatment regimen.

Treatment will be continued until tumor recurrence or for up to two years in the absence of recurrence. Prior data suggests a long-term mecanism of action of dutasteride in preventing tumor recurrences. Therefore, in the event of tumor recurrence, patients will be offered the option to continue dutasteride treatment for a total duration of up to two years. The decision to continue or discontinue treatment, as well as the reasons for this decision, will be documented.

Regarding analyses, the male cohort is designed to provide the first prospective data on efficacy; data will be compared to a historical control cohort, while also collecting adherence and safety data specific to men with low grade NMIBC.

The parallel female cohort is primarily intended to assess feasibility of recruitment and safety. In the published literature and our own institutional data, women represent approximately 25% of patients with low grade NMIBC. Recruitment of female patients is therefore more challenging, compounded in part by the limited safety data available and the absence of demonstrated urinary benefits. Consequently, this cohort aims to determine whether inclusion of women in a subsequent phase 3 study will be feasible and safe.

• Study Type: Interventional
• Enrollment (Estimated): 95
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Paul Toren Principal Investigator, MD; Phone Number: 418 525 4444; Email: Paul.Toren@crchudequebec.ulaval.ca
• Study Contact Backup: Name: Marjorie Besançon, PhD; Phone Number: 418 525 4444; Email: marjorie.besancon@crchudequebec.ulaval.ca

Study Locations

• Canada
  • Quebec
    • Québec, Quebec, Canada, G1G 5X1
      • Recruiting
      • CHU de Québec - Université Laval
      • Contact: Marjorie Besançon, PhD; Phone Number: 418 525 4444; Email: marjorie.besancon@crchudequebec.ulaval.ca
      • Contact: Catherine Gérard, PHd; Phone Number: 418 525 4444; Email: Catherine.Gerard@crchudequebec.ulaval.ca
      • Principal Investigator: Paul Toren, MD, PHD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged 18 or greater;
• Patients with histologically confirmed low grade non-muscle invasive urothelial carcinoma. Patients with any mix of low- and high-grade urothelial carcinoma remain eligible given the frequent histological heterogeneity and the presence of a low grade component;
• Patients have not been recommended for a course of intravesical BCG or chemotherapy induction treatment by their urologist;
• Male patients with partners of child-bearing potential must agree to 2 acceptable forms of birth control and be continued for at least 6 months after study drug is discontinued.

Exclusion Criteria:

• Patients who are scheduled to receive BCG therapy or have received BCG therapy within the last 5 years will be ineligible for enrollment.
• Patients who are scheduled to receive intravesical chemotherapy or have received an induction course of intravesical chemotherapy within the last 5 years will be ineligible for enrollment. Patients who received a single, post-operative (<24h) intravesical chemotherapy (e.g. gemcitabine, epirubicin or mitomycin C) dose are eligible.
• Patients with clinical hypogonadism, those on androgen replacement therapy, or those with prostate cancer or other diseases treated with various forms of hormonal therapy will be ineligible for study enrollment.
• Patients receiving 5-alpha-reductase inhibitors within the last 2 years are ineligible for enrollment.
• Patients with a history of allergy or severe adverse reaction to finasteride or dutasteride are ineligible for enrollment.
• Patients with a history of liver disease whose hepatic enzymes, alkaline phosphatase or bilirubin are greater than twice the upper limit of normal will be ineligible. Nonetheless, patients with Gilbert's disease may be accepted in the study.
• Patients with multiple hospital admissions for heart failure within the previous 12 months or who have unstable cardiovascular status will be ineligible for enrolment.
• Female patients with child-bearing potential are ineligible for enrollment, which is defined as any female under 50 years of age. Exceptions to this age limit may be permitted on a case-by-case basis by the Principal Investigator, based on documented confirmation that there is no child-bearing potential (such as a female without a uterus).
• Patients receiving chronic treatment with potent CYP3A4 inhibitors, including but not limited to ritonavir, ketoconazole, verapamil, diltiazem, cimetidine, troleandomycine, or ciprofloxacin, are ineligible for participation in the study. Occasional use of CYP3A4 inhibitors such as ciprofloxacin for an infection is not prohibited.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dutasteride 0.5 mg oral treatment daily; Participants will receive dutasteride 0.5 mg orally once daily for up to 2 years, or until tumor recurrence. Treatment may be continued after recurrence up to 2 years total, if the patient chooses to continue.	Drug: Dutasteride (0.5mg); Dutasteride 0.5 mg orally once daily. Treatment begins after enrollment and continues for 2 years or until tumor recurrence. Patients may opt to continue treatment after recurrence for a total of 2 years.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of NMIBC recurrences in patients treated with dutasteride	To facilitate historical comparisons, a pathologic definition of recurrence is selected. Thus, investigators will be mandated to perform confirmatory biopsies or surgical resection of recurrences. For the female population, recruitment will be compared to the male population based on the established 1:3 ratio of female to male patients.	From enrolment until first recurrence or 4 years of extended follow-up, whichever occurs first

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to surgery	Time to surgery under general anesthesia: time from enrolment until surgery for suspected recurrence of bladder cancer	From enrolment until surgery for suspected recurrence of bladder cancer or 4 years of extended follow-up, whichever occurs first
Number of tumour recurrences:	This is defined as the number of recurrences per patient.	From enrolment until first recurrence or 4 years of extended follow-up, whichever occurs first
Number of tumours at recurrence	This is defined as the number of tumors at the recurrence. This information is based on cystoscopic findings at time of the cystoscopy preceding surgical resection or the cystoscopy without anesthesia at which the biopsy indicating recurrence was taken.	From enrolment until first recurrence or 4 years of extended follow-up, whichever occurs first
Concordance of cystoscopic recurrence with pathologic recurrence	The proportion of suspected pathologic recurrences which were confirmed urothelial carcinoma on pathologic analysis	From enrolment until 4 years of extended follow-up, whichever occurs first
Quality of life assessed by the European Organisation for Research and Treatment of Cancer(EORTC) Quality of Life Questionnaire (QLQ) non-muscle invasive bladder cancer questionnaire(NMIBC) module 24	Quality of life will be evaluated with the EORTC QLQ-NMIBC24 questionnaire as a global score (linear transformation to 0-100, higher=better).	From enrolment to 24 months (end of treatment)
Urinary symptoms assessed by Bladder Utility Symptom Score (BUSS)	Urinary symptoms will be evaluated using BUSS questionnaire (0-100, higher=better)	From enrollment until 2 years (end of treatment)
Urinary symptoms assessed by the Internation Prostate Symptom Score (IPSS) questionnaire	Urinary symptoms will be evaluated using the IPSS(0-35, mild (0-7), moderate (8-19), or severe (20-35)) questionnaire among male patients.	From enrollment until 2 years (end of treatment)
Incidence of tumour progression	The proportion of patients who experienced tumor progression at the end of follow-up. Progression is defined as a recurrence with an increase in tumour grade to high grade, or an increase in stage, or the new presence of CIS.	From enrolment until first progression or 4 years of extended follow-up, whichever occurs first

Collaborators and Investigators

• Sponsor: Paul Toren

Study record dates

Study Major Dates

• Study Start (Actual): March 25, 2026
• Primary Completion (Estimated): April 2, 2030
• Study Completion (Estimated): April 2, 2032

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 19, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: recurrence; 5-alpha-reductase inhibitor; Low-grade bladder cancer
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Disease Attributes; Urologic Neoplasms; Urinary Bladder Diseases; Pathological Conditions, Signs and Symptoms; Recurrence; Urinary Bladder Neoplasms; Polycyclic Compounds; Steroids; Fused-Ring Compounds; Azasteroids; Steroids, Heterocyclic; Dutasteride
• Other Study ID Numbers: MP-20-2026-8412

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No