Brief Title: Testing Shorter Duration Radiation Therapy Versus the Usual Radiation Therapy in Patients Receiving the Usual Chemotherapy Treatment for Bladder Cancer, ARCHER Study

INTRODUCTION

• Org Study ID: NRG-GU015
• Secondary ID: N/A
• NCT ID: NCT07097142
• Sponsor: NRG Oncology

BRIEF SUMMARY

This phase III trial compares the effect of decreased number of radiation (ultra-hypofractionated) treatments to the usual radiation number of treatments (hypofractionation) with standard of care chemotherapy, with cisplatin, gemcitabine or mitomycin and 5-fluorouracil for the treatment of patients with muscle invasive bladder cancer. Hypofractionated radiation therapy delivers higher doses of radiation therapy over a short period of time. Ultra-hypofractionated radiation therapy delivers radiation over an even shorter period of time than hypofractionated radiation therapy. Cisplatin is in a class of medications known as platinum-containing compounds. It works by killing, stopping or slowing the growth of tumor cells. Gemcitabine is a chemotherapy drug that blocks the cells from making DNA and may kill tumor cells. Chemotherapy drugs, such as mitomycin-C and 5-fluorouracil (5-FU), work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving ultra-hypofractionated radiation may be equally effective as hypofractionated therapy for patients with muscle invasive bladder cancer.

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DETAILED DESCRIPTION

PRIMARY OBJECTIVE:

I. Demonstrate non-inferiority of ultra-hypofractionated (stereotactic body radiation therapy [SBRT]) compared to hypofractionated radiation therapy (RT) with a 10% non-inferiority margin (from 50% to 40%) in the rate of bladder-intact event-free survival (BI-EFS) at 3 years (corresponding to a hazard ratio < 1.32).

SECONDARY OBJECTIVES:

I. Compare the rates of urinary and bowel toxicity, patient-reported outcomes (PRO), event-free survival (EFS), metastasis-free survival (MFS), and overall survival (OS) between the two treatment arms.

II. Compare and evaluate symptomatic adverse events and quality of life measures that are most meaningful to patients.

III. Evaluate circulating tumor deoxyribonucleic acid (ctDNA) as a biomarker to determine whether it is predictive of disease recurrence and as a secondary outcome variable.

EXPLORATORY OBJECTIVES:

I. Evaluate ctDNA, tissue-free minimal residual disease (tfMRD) and urine tumor DNA (utDNA) as biomarkers for predicting recurrence.

II. Evaluate tfMRD, obtained at the time of progression, to determine if it captures the presence of disease.

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I: Patients receive hypofractionated radiation therapy (RT) once daily (QD), Monday to Friday, for 20 treatments in the absence of disease progression or unacceptable toxicity. Patients also receive one of 3 systemic chemotherapy regimens per treating physician's choice: 1) cisplatin intravenously (IV) weekly for 4 weeks; 2) gemcitabine IV on days 1, 4, 8, 11, 15, 18, 22 and 25 or weekly for 4 weeks; or 3) mitomycin-C IV on day 1 and fluorouracil (5 FU), over 120 hours on days 1-5 and 22-26. Treatment is given in the absence of disease progression or unacceptable toxicity. Patients also undergo computed tomography (CT) scan and/or magnetic resonance imaging (MRI) or fluorodeoxyglucose (FDG) positron emission tomography (PET) throughout the study. In addition, patients may undergo optional blood and urine sample collection throughout the study, as well as an optional biopsy during cystoscopy during follow up.

ARM II: Patients receive ultra-hypofractionated RT QD, no more than twice weekly, for 5 treatments in the absence of disease progression or unacceptable toxicity. Patients also receive one of 3 systemic chemotherapy regimens per treating physician's choice: 1) cisplatin IV weekly for 4 weeks; 2) gemcitabine IV on days 1, 4, 8, 11, 15, 18, 22 and 25 or weekly for 4 weeks; or 3) mitomycin-C IV on day 1 and 5 FU, over 120 hours on days 1-5 and 22-26. Treatment given in the absence of disease progression or unacceptable toxicity. Patients also undergo CT scan and/or MRI or FDG PET throughout the study. In addition, patients may undergo optional blood and urine sample collection throughout the study, as well as an optional biopsy during cystoscopy during follow up.

After completion of study treatment, patients are followed up at week 16, every 3 months for 3 years then every 6 months to year 5.

• Overall Status
  Recruiting
• Start Date
  October 7, 2025
• Phase
  Phase 3
• Study Type
  Interventional