A trial of active surveillance and apalutamide for prostate cancer (TAPS01)

Cancer type:

Prostate cancer





This trial looked at a type of hormone therapy called apalutamide for early stage prostate cancer. It was for men whose cancer was contained within the prostate gland. This is called localised prostate cancer.

The trial was open for people to join between 2018 and 2019. The researchers published the results in 2022.

More about this trial

Prostate cancer sometimes grows very slowly and doesn’t get big enough to cause any symptoms. So some men don’t need treatment straight away. They have regular check ups, including blood tests and scans of the prostate. This is called active surveillance.  If there are signs that the cancer is growing, they then have treatment.  

When this trial was done, there was no treatment available to try and stop the cancer growing during active surveillance.

In this trial, the researchers looked at giving short term treatment to men during active surveillance. They used a drug called apalutamide. This is a type of hormone therapy. It blocks the effect of testosterone on prostate cells.
Researchers wanted to find out if this could slow down the growth of prostate cancer in men having active surveillance. And if so, reduce the need for men to have treatment in the future.

First the trial team wanted to run a small feasibility trial, to see if it would be possible to run a larger trial.

The main aims of this trial were to find out:

  • whether apalutamide could reduce the size of the prostate cancer (measured on MRI scans)
  • how long this lasted    
  • whether it would be possible to run a larger trial

Summary of results

The trial team found it should be possible to run a larger study. And that apalutamide could help reduce the size of the cancer for up 18 months after treatment.

Trial design
This trial was for men who had early stage prostate cancer and didn’t need standard treatment. They were having regular checks to see if their cancer had changed. This would help the doctors decide whether they needed treatment or not. It is called active surveillance.

The research team asked men if they’d like to join the trial, and about 4 out of 10 men (40%) said they would. Of the 11 men who agreed to join, 9 completed the treatment as part of the trial.

They all took apalutamide tablets once a day for 3 months. They had a scan before and after treatment to see if there had been any change in the size of their prostate cancer. They also completed questionnaires to see how the treatment had affected their quality of life.

The research team used scan results to measure the size (volume) of the prostate cancer. They measured it in centimetres cubed (cm³). They compared the size before treatment, at the end of treatment and at about 18 months after treatment.

The results showed that the prostate cancer had got smaller in everyone who took part. The scans after treatment showed that, on average, the prostate cancer was less than half the size it was before treatment. This is a reduction of more than 50%.

They also looked at the scans about 18 months after treatment. The average size of the prostate cancer was still about 20% smaller than it was before treatment.

Side effects and quality of life
The people taking part answered questions before and after treatment about:

  • their general health and quality of life
  • any prostate cancer symptoms they were having
  • any side effects of treatment

The results showed that their general quality of life went down slightly while having treatment. But this started to improve about 6 weeks after treatment.

The results before and after treatment were similar for many of the specific symptoms. But tiredness, constipation and diarrhoea got a bit worse for some people while they were having treatment.

Some people had an improvement in urinary symptoms such as needing to wee more often or more urgently.

Everyone taking part had at least one side effect of treatment. But nearly all were mild or didn’t last long. Some people had side effects such as a rash that were more severe.

As with other hormone treatments used to treat prostate cancer, some people had erection problems (erectile dysfunction). This also started to improve about 6 weeks after treatment

The trial team concluded that apalutamide had an effect on the size of prostate cancer and didn’t cause too many side effects. They think that the this could be the case for many months after treatment. They hope this will mean that fewer men need treatment for their cancer.

The team hope to run a larger phase 3 trial (called TAPS02). They plan to look at this treatment for men with early stage prostate cancer in more detail. 

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

Please note, this article is not in plain English. It has been written for health care professionals and researchers.

A Feasibility Study of the Therapeutic Response and Durability of Short-term Androgen-targeted Therapy in Early Prostate Cancer Managed with Surveillance: The Therapeutics in Active Prostate Surveillance (TAPS01) Study
T Barrett and others
European Urology Open Science (2022). Volume 38, pages 17-24

Where this information comes from    
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.

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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 Vincent J Gnanapragasam

Supported by

Cambridge University Hospitals NHS Foundation Trust
Cambridge Clinical Trials Unit
University of Cambridge

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.

Keith took part in a trial looking into hormone therapy

A picture of Keith

"Health wise I am feeling great. I am a big supporter of trials - it allows new treatments and drugs to be brought in.”

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