A Clinical Study of MK-3120 in People With Bladder Cancer (MK-3120-003)

What this study involves

The registry says this study is recruiting. Individual locations may have different availability.

Study type

Interventional

Phase

Phase 1 / Phase 2

Age range

18 years - Not specified

Sex eligible

All sexes

Healthy volunteers

Not accepted

Participants

45 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

Researchers are looking for new ways to treat high-risk non-muscle invasive bladder cancer (HR NMIBC). NMIBC is cancer in the tissue that lines the inside of the bladder and has not spread to the bladder muscle or outside of the bladder. In standard treatment for HR NMIBC, doctors first remove the tumor with a procedure called transurethral resection of the bladder tumor (TURBT). Researchers want to learn if using MK-3120, the study medicine, can treat HR NMIBC after TURBT. The goal of this study is to learn about the safety of MK-3120 and if people tolerate it.

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

Inclusion Criteria:

• Has histologically confirmed carcinoma in situ (CIS) +/- papillary high-risk non-muscle invasive bladder cancer (NMIBC), confirmed locally.
• Is an individual whose most recent transurethral resection of bladder tumor (TURBT) was performed within 12 weeks before allocation and showed high-risk NMIBC histology. For individuals with papillary tumors (Ta and T1), a complete TURBT must have been performed, as characterized by attainment of a visually complete resection of all papillary tumors (Ta and T1).
• Is either: a) Bacillus Calmette-Guérin (BCG)-naïve, defined as either having never received BCG or having received BCG more than 2 years before CIS +/- papillary high-risk NMIBC recurrence. Recurrence must be at least 24 months from the last exposure to BCG with evidence of complete response during the 2-year period post-BCG OR; b) BCG-exposed and received adequate BCG therapy and had recurrence of CIS +/- papillary high-risk NMIBC \>12 months but ≤24 months after the last BCG dose.
• Human immunodeficiency virus (HIV)-infected participants must have well-controlled HIV on antiretroviral therapy.
• Participants who are hepatitis B surface antigen positive are eligible if they have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks, and have undetectable HBV viral load prior to allocation.
• Participants with history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable at screening.

Exclusion Criteria:

• Has history of or current locally advanced (ie, T2, T3, T4) or metastatic urothelial cancer (UC).
• Has concurrent extravesical (ie, urethra, ureter, renal pelvis) non-muscle invasive UC or history of extravesical non-muscle invasive UC that recurred within the last 2 years.
• Has active total bladder incontinence, active urinary tract infection, neurogenic bladder, or urethral stricture.
• Has a condition that would prohibit normal voiding (or holding bladder voiding for 1 to 2 hours).
• Has uncontrolled, significant cardiovascular disease or cerebrovascular disease, including New York Heart Association Class III or IV congestive heart failure, unstable angina, myocardial infarction, uncontrolled symptomatic arrhythmia, prolongation of QTcF interval to \>470 ms, and/or other serious cardiovascular and cerebrovascular diseases within the 6 months preceding study intervention.
• Has history of documented severe dry eye syndrome, severe Meibomian gland disease and/or blepharitis, or severe corneal disease that prevents/delays corneal healing.
• HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease.
• Has known additional malignancy that is progressing or has required active treatment within the past 3 years.
• Has known active central nervous system metastases and/or carcinomatous meningitis.
• Has active infection requiring systemic therapy.
• Has a history of (noninfectious) pneumonitis/interstitial lung disease (ILD) that required steroids, or has current pneumonitis/ILD.
• Has not adequately recovered from major surgery or has ongoing surgical complications.

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Not applicable

Masking

No masking

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (17)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

17 locations

Study team and timeline

Lead sponsor

Merck Sharp & Dohme LLC

Study start

Dec 9, 2025 Actual

Primary completion

Jul 30, 2027 Estimated

Study completion

Feb 28, 2029 Estimated

First posted

Oct 30, 2025 Actual

Last updated

Nov 10, 2026 Actual

Official study contacts