A trial comparing 2 ways of taking sunitinib or pazopanib for advanced kidney cancer (STAR)

Cancer type:

Kidney cancer
Renal cell cancer
Secondary cancers




Phase 2/3

This trial compared taking sunitinib or pazopanib continuously with having planned breaks in treatment. It was for people with advanced renal cell cancer.

The trial was open for people to join between 2012 and 2017. The team published the results in 2023.

More about this trial

This trial was for people with a type of kidney cancer called renal cell cancer. This is the most common type of kidney cancer in adults.

Advanced kidney cancer means it has grown outside of the kidney or spread to another part of the body. When this trial was done, doctors often used sunitinib or pazopanib to treat advanced kidney cancer. These are targeted treatments. They help stop the signals that cancer cells need to divide and grow.

Sunitinib and pazopanib are both tablets that you take every day. People usually continued treatment until their cancer started to grow again or the side effects were too much to cope with.

Researchers wanted to find out if having breaks in treatment helps reduce side effects without affecting how well it works. They call this a planned treatment break.

The people in this trial were put into a treatment group at random:

  • half had continuous treatment (standard treatment)
  • half had planned treatment breaks

The people who had treatment breaks had treatment for just under 6 months (24 weeks) to begin with. Then they stopped treatment for a while. They had regular appointments and scans. If there were signs that the cancer started to grow again, they had more treatment.

The main aim of this trial was to find out how well sunitinib and pazopanib worked if people had planned treatment breaks.

Summary of results

This trial showed there wasn’t much difference between having continuous treatment or breaks in treatment. But the team couldn’t say for sure that the two were as good as each other.

A total of 920 people joined this trial. There were:

  • 461 people in the group having continuous treatment
  • 459 people in the group having planned treatment breaks

The trial team looked at how long people lived for. They found it was:

  • 28 months for those who had continuous treatment
  • 27 months for those who had treatment breaks

When they looked at how many people had died, they found it was:

  • 335 people (73%) who had continuous treatment
  • 343 people (75%) who had treatment breaks

Side effects

Non serious side effects
Most people taking part had at least one side effect during the trial. These may have been caused by the trial treatment. But they may have been caused by something else such as other medication, the cancer itself or another medical condition.

Many of these were mild or didn’t last long. Some people had side effects that were a bit more severe. The most common of these were:

  • increased blood pressure
  • a change in liver function
  • extreme tiredness (fatigue)

A few more people who had treatment breaks had increased blood pressure and fatigue.

Serious side effects
Doctors can class a side effect as serious if people need long term care or hospital treatment. Or if it’s particularly important to the trial treatment.

Some people in this trial had a more serious side effect:

  • just under 2 out of 10 people (19%) who had continuous treatment
  • more than 2 out of 10 people (23%) who had treatment breaks

The most common of these were:

  • stomach problems
  • infection
  • lung problems

12 people died because of side effects from treatment. This was 3 people (0.7%) who had continuous treatment and 9 people (2%) who had treatment breaks. The side effects included:

  • problems with the heart or blood vessels
  • bleeding problems
  • liver problems

The team concluded that there wasn't much difference between the two groups. Having treatment breaks didn't work quite as well as having continuous treatment. So they couldn't say for sure that the two ways of having treatment were as good as each other.

The team say that having planned treatment breaks is not likely to have much effect on how long people live. They suggest it could be considered as an option for people who want to have a break in treatment.

More detailed information
There is more information about this research in the reference below.

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Temporary treatment cessation versus continuation of first-line tyrosine kinase inhibitor in patients with advanced clear cell renal cell carcinoma (STAR): an open-label, non-inferiority, randomised, controlled, phase 2/3 trial
J Brown and others
The Lancet, 2023. Volume 24, issue 3, pages 213 – 227.

Where this information comes from
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Janet Brown

Supported by

Cancer Research UK Leeds Clinical Trials Unit at University of Leeds
University of Sheffield
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer
NIHR Health Technology Assessment (HTA) programme

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Cara took part in a clinical trial

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"I am glad that taking part in a trial might help others on their own cancer journey.”

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