A trial looking at treating dry mouth after radiotherapy for head and neck cancer (The LEONIDAS-2 study)

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Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Head and neck cancers
Laryngeal cancer
Mouth (oral) cancer
Nasal and paranasal sinus cancer
Nasopharyngeal cancer
Pharyngeal cancer
Salivary gland cancer





This trial is looking at using a device to treat dry mouth after radiotherapy for head and neck cancer.

Doctors often treat head and neck cancer with radiotherapy. A side effect of this can be a dry mouth. This can be very distressing because it can change the way you talk and eat. Doctors can treat a dry mouth but the treatments are not very good and can have side effects. So they are looking for better ways.

The researchers think a new medical device could help. The device is like a clear plastic protector that fits over your lower teeth. It delivers mild electrical stimulation to the gums. The researchers hope this can increase the amount of spit (saliva) and reduce the symptoms of dry mouth.

The aims of this trial are to find out if this device can

  • Reduce the symptoms of dry mouth
  • Increase the amount of saliva
  • Improve quality of life

Who can enter

You may be able to enter this trial if

  • You have had a full course of external radiotherapy Open a glossary item for head and neck cancer (you need to have had a total dose of at least 40 Gray (Gy) Open a glossary item and your specialist can tell you this)
  • Your radiotherapy was at least 4 months ago
  • You have moderate to severe dryness of the mouth - your doctor will test you for this
  • Your salivary glands can still make extra spit (saliva) when you are chewing and your doctor has confirmed this
  • You have not had both your parotid glands removed
  • You are at least 18 years old

You cannot enter this trial if

  • You have mild dryness of the mouth from your radiotherapy  --- your doctor will test you for this
  • Your salivary glands can’t make extra spit (saliva) when you are chewing and your doctor has confirmed this
  • You are using the drug pilocarpine to stimulate your salivary glands
  • You are using another medical device for example a pacemaker or hearing aid
  • You are allergic to the materials used in the device

Trial design

This trial will recruit 84 people from University College London Hospital and Bradford Hospital. It is a randomised trial. You will be put into 1 of 2 groups. Neither you nor your doctor can choose which group you are in. And neither of you will know which group you are in. This is called a double blind trial. People in group 1 use the active device and people in group 2 use a dummy device.

Both devices are custom made to fit. You will take it home and wear it over your lower teeth when needed. You can remove the device and store it in the container provided when you don’t need it. The team will explain to you how and when to use it. You use the device for 1 year.

Below is a picture of the device.

LEONIDAS-2 study device

The researchers will ask you to write in a diary how many times a day you use the device and also once a week how dry your mouth feels. They will also ask you to fill out 3 questionnaires before you start and at 1, 2, 4, 6, 8 and 12 months. They will ask about side effects and how you are feeling. This is called a quality of life study.

The researchers will also ask for a sample of saliva before and after treatment. They will compare the 2 samples to find out how well the device works. You must agree to this to take part in this trial.

Hospital visits

You see the doctor before taking part in this trial and have some tests. These include

  • Examining  your mouth, gums and teeth
  • Measuring how dry your mouth is
  • Measuring how much saliva you make
  • Assessing the side effects of your radiotherapy

You go to the hospital to have the device made to fit over your teeth. When it is ready you see the doctor to make sure it fits properly. The doctor will explain when and how to use it.

You then see the doctor at 1, 2, 4, 6, 8 and 12 months to measure how much saliva you make and how dry your mouth is.  

Side effects

The researchers don’t anticipate any problems with using the device.

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

Prof Stephen Porter

Supported by

NIHR Clinical Research Network: Cancer
NIHR Research for Patient Benefit (RfPB) Programme
University College London (UCL)

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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.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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