What is Aldesleukin (Proleukin®)?

Aldesleukin (Proleukin®) is 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 the type of cancer you have.

Aldesleukin is a type of immunotherapy drug. 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.

During treatment you will have regular blood tests to monitor the effect of the drug on your blood cells and organs.

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 course of treatment

Your doctor or nurse will explain how often you will have the drug and how long your treatment will last. You usually have a course of several cycles of treatment over a few months.

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.

You may also have some side effects that we have not listed here. 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. After your treatment is over, most side effects start to improve.

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 sometimes called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given 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
  • your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) a lot, or discomfort when you pass urine.

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, until your cell count increases.

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. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:

  • pale skin
  • lack of energy
  • feeling breathless
  • feeling dizzy and light-headed.

Tell your doctor or nurse if you have these symptoms.

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. Flu-like symptoms include:

  • a high temperature
  • lack of energy (lethargy)
  • chills
  • 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.


This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

If you have diarrhoea:

  • try to drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Let your doctor know straight away if you:

  • have signs of bleeding from the back passage
  • have black stools
  • are vomiting up blood or vomit that looks like coffee grounds.

Feeling sick

Your doctor will give you anti-sickness drugs to help prevent or control sickness during your treatment. 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 often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or are sick (vomit) more than once in 24 hours, contact the hospital as soon as possible. They will give you advice. Your doctor or nurse may change the anti-sickness drug to one that works better for you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Skin changes

Aldesleukin 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, aldesleukin may make it worse.

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.

Effects on the lungs

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

  • a cough
  • wheezing
  • breathlessness.

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

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 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.

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 build-up

You may gain weight, or your face, ankles and legs may swell. This improves slowly after your treatment has finished. Your doctor may give you drugs to help reduce the swelling.

Sore mouth and throat

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

If your mouth or throat 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 and throat.

Sucking ice chips may sometimes help relieve mouth or throat pain. But if you are having radiotherapy to the head or neck, do not suck on ice. It can cause damage.

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.


This treatment may cause headaches. If you have headaches, tell your doctor. They may give you painkillers to help.

Blocked nose or nosebleeds

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

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

Effects on the heart

This treatment can affect the way your heart works. Your doctor may do tests to see how well your heart is working. You may have these tests before, during, and sometimes after treatment.

Contact a doctor straight away if you:

  • have pain or tightness in your chest
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

Other conditions can cause these symptoms. But it is important to get them checked by a doctor.

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.


This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital for advice. Your doctor can give you drugs called laxatives to help.

Hair thinning

Your hair may become thinner when you are taking this treatment. This is usually mild. Ask your nurse for advice if you are worried about this.

Liver changes

This drug may cause changes in the way your liver works. This will return to normal when the treatment finishes. You are very unlikely to notice any problems, but your doctor or nurse will take regular blood samples to check your liver is working properly.

Raised blood sugar levels

This treatment may raise your blood sugar levels. Symptoms of raised blood sugar include:

  • feeling thirsty
  • needing to pass urine more often than usual
  • feeling 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 change 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.

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
  • tingling in your hands or feet.

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:

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

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

You can help reduce the risk of developing a blood clot by:

  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.


Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.

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 get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.


You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.


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 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.