What is Aldesleukin (Proleukin®)?

Aldesleukin (Proleukin®) is a type of immunotherapy drug used to treat kidney cancer. It is sometimes called interleukin-2 or IL2. It may sometimes be used to treat other cancers. It is best to read this information with our general information about immunotherapy and the type of cancer you have.

Aldesleukin is a man-made version of a protein the body produces naturally in very small amounts. It stimulates the body’s immune system (our defence against infection and disease) to fight some types of cancer. It encourages a particular type of white blood cell to recognise and destroy the cancer cells.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How aldesleukin is given

You may be given aldesleukin as a drip during a stay in hospital. Or you can have it at home as an injection under the skin.

During treatment you usually see a cancer doctor, a cancer nurse or specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have treatment.

You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your treatment. Your nurse will tell you when it is likely to be ready.

You may have aldesleukin either:

  • as a drip into a vein (intravenous infusion)
  • as an injection under the skin (subcutaneously).

If you have aldesleukin as a drip, you need to stay in hospital for close monitoring. It is given at higher doses which means the side effects are more severe and can be serious. Your doctors and nurses will monitor you carefully and make sure the side effects are controlled.

If you have aldesleukin as an injection under the skin, you or a relative or carer can be taught how to give it. If this is not possible, a district nurse or practice nurse can give it to you.

Your doctor or specialist nurse will explain how often you will have the drug and how long your treatment will last. They will also talk to you about the side effects. During treatment you will have regular blood tests to monitor the effect of the drug on your blood cells and organs.

Your course of treatment

You usually have a course of several cycles of treatment over a few months. Your nurse, pharmacist or doctor will discuss your treatment plan with you.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them.

Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Common side effects of aldesleukin

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection.

If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor or nurse if you have any bruising or bleeding that you can’t explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Flu-like symptoms

These can happen soon after the drug has been given. They include a high temperature, lack of energy (lethargy), chills and muscle and joint pains.

If you have these symptoms, it is important to drink plenty of fluids and get plenty of rest. Your doctor may prescribe paracetamol to reduce these side effects.

Feeling sick

You may feel sick in the first few days after treatment. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24 hours, contact the hospital as soon as possible. They will give you advice and may change the anti-sickness drug to one that works better for you.

If you have a poor appetite, talk to your specialist nurse or ask to see a dietitian. They can give you advice on improving your appetite and keeping your weight stable.

Skin changes

This treatment may cause your skin to redden or become darker and it may become dry and itchy. Your doctor can prescribe creams to help. Tell your doctor straight away if you develop a rash or your skin peels or blisters. If you already have a skin complaint, such as psoriasis, this treatment may make it worse.

During treatment and for several months afterwards, you will be more sensitive to the sun and your skin may burn more easily than normal. You can still go out in the sun, but you should wear a suncream with a high sun protection factor (SPF). You should also cover up with clothing and a hat.

Swelling or redness at the injection site

If you have this drug as an injection under the skin, you may get redness and swelling around the area where it is given (injection site). You can reduce this by changing the injection site with each injection you have. Your nurse can give you advice.

Diarrhoea or pain in the tummy

Your doctor can prescribe drugs to control diarrhoea. Let them know if it is severe or if it does not get better. Make sure you drink at least 2 litres (3½ pints) of fluids every day if you have diarrhoea.

Let your doctor know straight away if you have pain in your tummy, signs of bleeding from the back passage or black stools, or if you are vomiting up blood (or vomit that looks like coffee grounds).

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor straight away if you:

  • develop a cough
  • feel breathless
  • cough up blood.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Changes in mood or behaviour

Let your doctor know straight away if you:

  • feel anxious, agitated or confused
  • have problems sleeping
  • or, less commonly, see things that are not there (hallucinations).

It is important not to drive or operate machinery if you notice these effects.

Feeling tired

Feeling tired (fatigue) is a common side effect. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Muscle or joint pain

You may get pain in your joints or muscles during treatment. Occasionally, this can be severe. Tell your doctor if this happens so they can prescribe painkillers. Let them know if the pain does not get better. They can usually increase or change your painkillers to help.

Effects on the kidneys

Your doctor will check how well your kidneys are working with a blood test before and during your course of treatment.

In some hospitals, you will be asked to measure and record everything you drink and the amount of urine you pass. You may be given medicine to help you pass more urine if you do not pass enough.

Fluid retention

You may put on weight or your face, ankles and your legs may swell. This slowly gets better once your treatment has finished. Sometimes, drugs can be given to help reduce the swelling.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco and foods that irritate your mouth.

Eye problems

Your eyes may become sore, red or itchy (conjunctivitis). If this happens, tell your doctor. They can prescribe eye drops to help. If you notice any changes in your vision, contact your doctor so that they can check your eyes.

Blocked nose or nosebleeds

Tell your doctor if you have a blocked nose. Let them know straight away if you have nosebleeds.

Liver changes

This treatment may cause changes in the way your liver works. This will return to normal when the treatment finishes. Your doctor or nurse will take regular blood samples to check your liver is working properly.

Raised blood sugar levels

This treatment can raise your blood sugar levels. If you have a raised blood sugar level, you may:

  • feel thirsty
  • need to pee (pass urine) more often
  • feel tired.

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to adjust your insulin or tablet dose.

Changes to calcium or thyroid hormone levels

This treatment can lower or raise your blood calcium levels or your thyroid hormone levels. This may cause different symptoms. Your doctors may take regular blood tests. So, any changes are usually discovered before you get any symptoms.

Leaking from tiny blood vessels (capillary leak syndrome)

This can happen a few hours after you first have this treatment as a drip (infusion). It happens when fluid leaks from tiny blood vessels called capillaries. This can cause low blood pressure and make you unwell. Because you have the treatment in hospital your nurses and doctors will be checking you for any of these signs.

Tell your nurse or doctor immediately if you:

  • feel faint, dizzy or sick
  • have diarrhoea
  • feel breathless
  • have a fast heartbeat
  • notice swelling in your ankles, legs or face.

Less common side effects of aldesleukin

Changes in the way your heart works

In some people, this treatment can affect how the heart works. This depends on the dose you have. Tell your doctor straight away if you notice any changes to your heartbeat, if you have pain or tightness in your chest, or if you feel breathless.

Low blood pressure

The hospital team will check your blood pressure regularly during treatment. It is important to tell your doctor if you feel dizzy or faint.

Effects on the nerves

This treatment can cause inflammation of the nerves. This can sometimes cause very serious problems.

Contact the hospital straight away if you have unusual weakness in your arms, legs or face, or have tingling in your hands or feet.

It is important to tell your doctor or nurse straight away if you feel ill or have severe side effects. This includes any we do not mention here.

Other information about aldesleukin

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain.

If you have any of these symptoms, contact a doctor straight away.

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.


Your doctor will advise you not to become pregnant or father a child while having this treatment. The drugs may harm a developing baby. It is important to use effective contraception during, and for a few months after, treatment. You can talk to your doctor or nurse about this.


Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.


Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.