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RE-ARM in red bolded text in front of a multi coloured concentric circle design

RE-ARM: A trial of radiotherapy for people receiving atezolizumab for cancer of the urinary system

Enrolling participants

What is the study about? 

RE-ARM investigates whether giving radiotherapy to people receiving treatment for advanced bladder cancer helps the treatment work better.

People with advanced bladder cancer which has spread around the body are often treated with atezolizumab. Atezolizumab is a type of treatment called an immunotherapy. It works by reactivating the body’s immune system to attack the cancer cells. But atezolizumab doesn’t always work to shrink peoples’ cancer straight away, and may not ever work well for some people.

Giving radiotherapy alongside atezolizumab may help kickstart peoples’ immune systems and help the atezolizumab work better to shrink their cancer.

RE-ARM is investigating whether giving a short course of radiotherapy to people who have been receiving atezolizumab, or a similar drug called avelumab, could help the immunotherapy treatment work better. 

RE-ARM infographic. Does radiotherapy help immunotherapy work better for advanced bladder cancer patients? Immunotherapy doesn't work for everyone. Radiotherapy may help by increasing immune response. Does radiotherapy improve response to immunotherapy?

Image: Does radiotherapy help immunotherapy work better for advanced bladder cancer patients?

Who is included in the study?

RE-ARM includes people with advanced bladder cancer who have been treated with atezolizumab or avelumab for up to six months without their cancer shrinking. People with cancers of other parts of the urinary tract can also join the trial if their treatment has not been working. 102 people will be included in RE-ARM, from NHS hospitals across the UK.

What are the study treatments?

Everyone who joins RE-ARM, including those who were taking avelumab, receive atezolizumab after joining the trial. Participants are in two treatment groups:

  • Atezolizumab treatment alone
  • Atezolizumab treatment plus a short course of radiotherapy

Participants have regular check ups during and after their treatment and we collect information about how they are getting on until the study is completed.

Further information for participants

Patient Information Sheet

A detailed summary is available on Cancer Research UK’s website

Further information for healthcare professionals 


Contact details and regulatory information

Chief Investigator: Professor Robert Huddart, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust

ICR-CTSU scientific lead: Professor Emma Hall

Trial management contact: [email protected]

Sponsor: The Institute of Cancer Research

Funding: Cancer Research UK (CRUKE/19/009) and Roche Products Ltd

Trial identifiers

EUDRACT number: 2020-004893-23

REC reference: 21/LO/0150

CPMS ID: 48346


Publications and presentations

A. Wilkins, E. Hall, R. Lewis, H. Gribble, A. Melcher, R. Huddart, RE-ARMing the Immune Response to Bladder Cancer with Radiotherapy, Clinical Oncology, 2022

R. Huddart, R. Lewis, S. Brown, E. Cheadle, A. Choudhury, S. Crabb, C. Emery, H. Gribble, J. Haviland, T. Illidge, M. Linch, H. Scowcroft, A. Sohaib, I. Syndikus, R. Walshaw, A. Wilkins, A. Melcher, E. Hall, RE-ARM – a multicentre phase II randomised controlled trial of radiotherapy plus atezolizumab in metastatic urothelial carcinoma – investigating the abscopal effect. Presented at: National Cancer Research Institute Cancer Conference; 2021 Nov 8-12

Clinical trials

Division of Clinical Studies

The division carries out or coordinates high-quality trials and translational research at both an early phase – typically to test new targeted drugs – and a later stage.