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Pembrolizumab and Lenvatinib A1553


Information leaflet on Pembrolizumab and Lenvatinib treatment


This leaflet provides information on a treatment known as pembrolizumab and Lenvatinib.  It will explain what this is, when and how it will be given.  It will also tell you about common side effects that you may experience.  Contact telephone numbers and details of how to obtain further information on this treatment are given at the end of the leaflet.


What is pembrolizumab and Lenvatinib?

This is a course of treatment which consists of two drugs:

  • Pembrolizumab  - given as an infusion through a drip
  • Lenvatinib  - given as capsules

Pembrolizumab is an artificially made antibody which attaches itself to cancer cells and stops them from growing.  It is an immunotherapy, it works by helping the immune system to attack the cancer cells. It is not chemotherapy.


Lenvatinib is a cancer treatment which is given as capsules.  It works by stopping a particular type of cancer cell from growing.


Why am I having this treatment?

Your doctor has prescribed this treatment because it has been found to be effective in treating your type of cancer.


How often will I receive this treatment? 

You will receive the pembrolizumab treatment once every 6 weeks. The Lenvatinib capsules are taken every day.   

Your doctor will discuss with you how long you will have your treatment for.


How will my treatment be given?

Your Pembrolizumab is given through a drip into a vein in the back of your hand or arm.

Alternatively, if finding a vein is difficult, it may be suggested that a fine tube called a PICC is inserted into a large vein in your upper arm.  This line can remain in place for the whole of your treatment.  Your doctor or nurse will explain this in more detail, if required.


We have a leaflet that tells you more about PICC lines, if needed.



How should I take the Lenvatinib capsules?

You should take your capsules once a day with or without food.  Swallow them whole with a large glass of water.  You can choose what time of the day to take your capsules but it is important to take them at about the same time each day

How many capsules will I need to take?

This will vary for each person.  The amount you need to take will be clearly marked on the box.  

What should I do if I forget to take my capsules?

If you miss a dose take within 12 hours.

Do not take the extra capsules when your treatment should have finished.  It is important that even if you have missed any doses you should finish the treatment at the planned time. 

What if I take too many capsules?

Please contact Velindre Cancer Centre immediately for advice.  The telephone numbers are at the end of the leaflet.

How should I store my Lenvatinib capsules?

You should store your capsules in their original packaging in a safe place away from children.  They should be kept in a cool dry place.  

Any unused capsules should be returned to the hospital Pharmacy or your local chemist for safe disposal.  

How long will I be in hospital?

You should be prepared to spend 1 – 2 hours at the hospital for your first treatment, and approximately 1 hour for the following treatments.


Can I bring relatives and friends with me?


You are welcome to bring someone to stay with you during your treatment. Space is limited so there is not usually room for more than one person.  Treatment areas are not suitable for young children.


How often will I see the specialist team?

You will be reviewed regularly by your specialist team either face to face or telephone consultation   Your team will let you know how often they will see you.  You will have regular blood tests and we will check how you are feeling and discuss any problems you may have. This is so we can check how the treatment is affecting you. 



What are the possible side effects?

There are many possible side effects with this treatment we have described the main side effects below. As with all medicines some patients can get side effects with Pembrolizumab and Lenvatinib.  Usually these side effects are mild or moderate.  The doctors, nurses and pharmacists can give you advice or answer any questions you may have. If you feel unwell and are unsure if it is related to this treatment please contact Velindre. The doctor, nurses and pharmacists can give you advice or answer any questions you may have.



If you are admitted to another hospital, you must inform the doctors and the nurses that you are taking Pembrolizumab and Lenvatinib.  It is possible you could be having an immune reaction and should be started on steroids. The doctors and nurses need to contact Velindre Cancer Centre for advice.  They can either telephone the treatment helpline or speak to your oncologist.


You will be given an alert card, please show this to the nurses or doctors if you are admitted to any hospital.



Hair loss

This treatment should not make you lose your hair.  However, a small number of people may experience some hair thinning.  We have a leaflet that tells you more about coping with hair loss.  Please ask your nurse if you would like a copy


Tiredness and fatigue

This treatment may make you feel more tired than usual.  It is important to listen to your body and rest if you need to; but carry out your normal activities if you feel able. Some people find it beneficial to take gentle exercise as well as rest. However, if you are becoming increasingly tired, telephone the treatment helpline; the number is at the end of the leaflet.


Skin reactions

Use a non-perfumed body wash and moisturising cream to help to prevent skin reactions.

This treatment may cause a rash which is dry and itchy and cause mild discomfort. You may experience mild pain, redness and swelling of your hands or feet.

For a small number of people this reaction may be more severe.  A severe rash would affect a large part of your body, may be painful and may become infected.

If you develop a severe rash you should contact the treatment helpline; the number is at the end of the leaflet.



Effects on your bowels

This treatment has been known to cause either constipation or diarrhoea. 

  • If you experience constipation it is important that you increase the amount of fluids you drink.  You may need laxatives.  You can speak to us or your GP for advice.


  • If you experience diarrhoea it is important that you drink plenty of fluids.  If you have 4 or more bowel movements in 24 hours above what is normal for you, or you have diarrhoea with stomach cramps, blood or mucus (slime) in your bowel motions please contact Velindre Cancer Centre immediately.  You should not take any anti-diarrhoea medication unless advised to do so by Velindre.




Nausea and vomiting are uncommon these days as we will give you anti-sickness medicines which are usually extremely effective.  If you are sick more than once in 24 hours despite taking regular anti-sickness medicine when you are at home after your treatment, contact Velindre Cancer Centre for advice.  The telephone number is at the end of the leaflet.



Fluid retention

You may experience fluid retention which can result in swelling of your ankles and legs.  Rarely this can result in breathlessness because of fluid on the lungs.  Please tell your doctor or nurse if this is a problem.


Myalgia (pain in the muscles)

Some patients may experience myalgia which is muscle or joint pain.   If you already have painkillers at home you may find they relieve the pain.  If this does not work please contact Velindre Cancer Centre.  The telephone number is at the end of the leaflet.


Effects on your thyroid hormone

Pembrolizumab may either increase or decrease the level of thyroid hormone.  We will be monitoring this regularly with blood tests.  If your thyroid hormone is increased, you may feel more anxious and have difficulty sleeping, have hot flushes or have a fast heart beat and feel very tired.  If your thyroid hormone is decreased you will feel tired, feel the cold easily, you may put on weight and become constipated.


High blood pressure  

Lenvatinib can cause an increase in blood pressure in some people.  Your blood pressure will need to be checked regularly during your treatment, especially when you first start taking the medication. If you have headaches, nosebleeds or feel dizzy let your doctor know.  High blood pressure can usually be controlled with capsules prescribed by your doctor. 

Protein in the urine

This can occur due to effects of Lenvatinib on the kidneys.  It doesn’t normally cause symptoms but requires careful monitoring.  Lenvatinib may be stopped if protein is found in the urine. 


Lenvatinib may sometimes cause bleeding problems. Tell your doctor if you take any medicines that may affect bleeding, such as Aspirin, Warfarin or vitamin E. If you bruise excessively or have excessive nose bleeds, ring the treatment helpline. The telephone number is at the end of the leaflet.


Bowel perforation

A small number of patients can develop a small hole in the wall of the bowel (perforation).  This is rare, but if you develop any abdominal pain or swelling contact the treatment helpline for advice.

Heart problems

Lenvatinib treatment may cause some heart problems

If you already have a heart condition or you take any heart medication, please tell your Velindre doctor before you start treatment with Lenvatinib. We will monitor your heart by using an ECG heart trace before you start treatment and at regular clinic visits. 

If at any time during your treatment you experience fluid retention (swelling) in your arms or legs, or palpitations (heart flutter or irregular heart beat) please seek contact Velindre Cancer Centre for advice. If you experience severe breathlessness or chest pain dial 999 or attend A&E without delay.


Other side effects

A small number of people may experience lung problems following pembrolizumab treatment.  If you develop a dry cough or notice that you are slightly short of breath please contact the treatment helpline. 


Some patients may find that this treatment can affect your vision. If this is severe contact the Treatment Helpline.


You may get headaches whilst on this treatment.  Try taking whatever painkillers you would normally take.  If these do not work please contact Velindre Cancer Centre for advice.


It is important you do not become pregnant or father a child whilst having this treatment as it could damage the unborn baby.

 Women should not breast feed whilst taking Lenvatinib.


This treatment reduces the effectiveness of oral contraceptives, you will need to use additional or alternative contraceptives


A small number of patients may find that they have a reduced ability to fight infection.


Sometimes cancer drugs can have very serious side effects which can be life threatening. It is important to inform Velindre cancer centre if you are concerned about any side-effects.


Blood Clots


A diagnosis of cancer can increase your risk of developing a blood clot (thrombosis), and having cancer treatment may increase this risk further.  It is important to tell your doctor immediately if you have symptoms such as pain, redness and swelling in your leg, or breathlessness and chest pain. 


Blood clots can be very serious.  However, most clots can usually be successfully treated with drugs to thin the blood.  Your doctor or nurse can give you more information


Slow wound healing  

Wounds may take longer to heal while you are having treatment with Lenvatinib. 



Side effects may continue for up to 18 months after treatment.  If you have any side effects contact the treatment helpline. If you are admitted to hospital or see your GP during this period, inform the doctor you have had Pembrolizumab, an immune therapy and give them your alert card.


Is it alright to take other medicines with Lenvatinib?

It is important to tell us about any other medicines you are taking.  There are a number of medications that you must not take with Lenvatinib, including over the counter medicines. You should also tell your GP and your pharmacist that you are taking Lenvatinib, if you are prescribed medication or wish to buy over the counter.


Can I drive whilst taking Lenvatinib?

Some people can feel very tired, slightly dizzy or have some blurred vision when they first start taking Lenvatinib.  You should not drive if you experience any of these side effects.  If these persist or cause any problems please talk to your doctor or nurse


Manufacturer’s patient information leaflets

Velindre leaflets provide information about very common and commonly reported side-effects (we are unable to list all of the common side effects), for more information regarding these and the less common side-effects please refer to the manufacturers patient information leaflets, obtained from Velindre pharmacy and/or on the internet at Sometimes patients may find these leaflets difficult to read however. Please ask if you would like a copy from your doctor or from Velindre pharmacy



Contact telephone numbers


Velindre Cancer Centre          029 2061 5888

Ask for the treatment helpline if you are unwell at home and need immediate advice at any time of the day or night.


Pharmacy department            029 2061 5888 ext 6223

Monday – Friday 9am – 5pm for queries about your medicines


Tenovus freephone                       0808 808 1010

cancer helpline


Macmillan freephone Helpline       0808 808 0000


7 days a week 8am – 8pm for general queries on cancer


This leaflet was written by health professionals.  The information contained in this leaflet is evidence based.  It has been approved by doctors, nurses and patients.  It is reviewed and updated every 2 years.





Prepared September 2022