A trial of telotristat etiprate for people who have symptoms of carcinoid syndrome (TELECAST)

Cancer type:

Neuroendocrine tumour (NET)




Phase 3

This trial looked at telotristat etiprate (LX1606) for people who have symptoms of carcinoid syndrome.

Neuroendocrine tumours (NETs) are a rare group of cancers. These tumours make and release hormones Open a glossary item. They are normally found in the digestive system Open a glossary item. The most common type that causes carcinoid syndrome are bowel ones.

This trial was open for people to join between April 2014 and April 2015. These results were published in 2018.

More about this trial

A NET produces serotonin which causes symptoms such as:

  • diarrhoea
  • frequent bowel movements
  • tummy (abdominal) pain
  • redness of the face (flushing)

This is carcinoid syndrome.

Doctors can treat carcinoid syndrome with drugs called somatostatin analogues. These drugs help. But they may stop working after a while. No other treatments were available:

  • if somatostatin analogues stopped working or
  • for people who couldn't or didn't want to take them

Researchers were looking for new treatments to help people in these situations. In this trial, they looked at a drug called telotristat etiprate. This reduces the production of serotonin.

This trial looked at different doses of telotristat etiprate to:

  • see which doses helped relieve the symptoms of carcinoid syndrome
  • learn more about the side effects

Summary of results

The trial team found telotrisat etpirate with somatostatin analogues helped people with diarrhoea caused by carcinoid syndrome.  

About this trial
This was a phase 3 trial. It was a randomised, double blind trial. Everyone was put into 1 of 3 groups. Neither they nor their doctor chose or knew which group they were in.

76 people took part in the trial.

  • 25 people had low dose of telotrisat etpirate 
  • 25 people had a high dose of telotrisat etpirate
  • 26 people had a dummy drug (placebo Open a glossary item)

Everyone had 12 weeks of treatment. This was the double blind part of the trial. After this the team told everyone which group they were in. 

They then had the choice to continue with telotrisat epitrate at the high dose for another 36 weeks. This is called the open label extension period. 

Before starting treatment everyone collected their urine for 24 hours. The team looked at the amount of a chemical called u5-HIAA in the urine. This chemical is made as part of the process of breaking down serotonin. Our body gets rid of it in urine. 

After 12 weeks of treatment people collected their urine again for 24 hours. The team looked at the difference in the amount of u5-HIAA between these 2 urine collections. 

The team found that there was a statically significant Open a glossary item difference in the level of u5-HIAA in both groups who had telotrisat epitrate compared with the dummy drug group. And for the majority of people this continued into the open label extension period.  

The team compared the symptoms of carcinoid syndrome people had in each group. They found that the form and firmness of the poo was significantly better for those who had telotrisat epitrate. 

Side effects
Most side effects were mild or moderate. People who had telotrisat epitrate reported more side effects than those who had the dummy drug. 

The most common side effects were:

  • feeling or being sick
  • diarrhoea or constipation
  • tummy (abdominal) pain or discomfort 
  • bloating of the tummy
  • indigestion

The team concluded that treatment with telotrisat epitrate for up to 48 weeks:

  • was acceptable 
  • had few side effects
  • had a lasting decrease in the level of u5-HIAA 

These results plus the results of the TELESTAR trial support the use of telotrisat epitrate with somatostatin analogues in people with diarrhoea caused by carcinoid syndrome.   

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.


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 Martyn Caplin

Supported by

Experimental Cancer Medicine Centre (ECMC)
Lexicon Pharmaceuticals

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.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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