Assessing Adaptive Radiotherapy and Chemotherapy for Muscle-Invasive Bladder Cancer (NRG-GU015, The ARCHER Trial)

05/12/2026

The NRG-GU015 clinical trial, also known as the “ARCHER study” is currently active and enrolling patients with cT2-cT3 muscle invasive bladder cancer (MIBC) that is clinically node negative. This study is designed to test whether ultra-hypofractionated radiation via stereotactic body radiation therapy is non-inferior to hypofractionated radiation in bladder-intact, event-free survival at 3 years following treatment.

“Despite bladder preservation being a standard option for muscle-invasive bladder cancer, outcomes remain suboptimal and treatment courses are burdensome. This trial is needed to determine whether cutting-edge, ultra-hypofractionated radiation can maintain cancer control while reducing toxicity and dramatically improve convenience and quality of life for patients,” stated Scott Delacroix, MD, of the Mary Bird Perkins Cancer Center and the Principal Investigator of the ARCHER study.

Patients enrolled into the ARCHER study will be stratified by clinical stage, type of radiosensitizing chemotherapy planned (cisplatin, gemcitabine, or mitomycin-C/5-fluorocuracil), and potential neoadjuvant therapy. Following stratification, patients will be randomly assigned to receive 4 weeks of radiosensitizing chemotherapy with either hypofractionated radiation therapy at 55 Gy over 20 fractions or ultra-hypofractionated radiation therapy at 32.5 Gy over 5 fractions.

In addition to the previously noted primary objective of this study, this trial also includes a number of secondary and exploratory objectives. Secondary objectives include comparing rates of urinary and bowel toxicity, patient-reported outcomes, metastasis-free survival, event-free survival, overall survival, symptomatic adverse events, and quality of life between treatments. Additionally, researchers will evaluate ctDNA as a biomarker to determine whether it is predictive of disease recurrence. Exploratory objectives include evaluating tissue-free minimal residual disease and urine tumor DNA as biomarkers for predicting recurrence and evaluating tfMRD at the time of progression to determine if it captures presence of disease.

“The ARCHER study has the potential to reduce toxicity and patient burden which ultimately improves outcomes for this patient population. We encourage sites to reach out with any questions or concerns and to continue to enroll patients on this very significant study,” added Himanshu Nagar, MD, at Memorial Sloan Kettering Cancer Center and the Co-Principal Investigator of the ARCHER study.

More information:

More on the ARCHER study can be found at ClinicalTrials.gov.

Protocol documents for the ARCHER study are available on CTSU.org.

This study has a patient study webpage available on NRGOncology.org.