Capivasertib and fulvestrant

What is capivasertib and fulvestrant?

Capivasertib and fulvestrant is a treatment for breast cancer that has spread to the surrounding tissue (locally advanced). Or if it has spread to other parts of the body (secondary or metastatic breast cancer).

It is for people whose breast cancer is hormone receptor positive and is HER2 negative. Your cancer must have one or more of the following gene changes (mutations):

• PIK3CA

• AKT1

• PTEN

To have capivasertib your cancer must have come back or not gone away after treatment with both of the following:

• an aromatase inhibitor such as anastrozole, exemestane or letrozole

• a type of cancer growth blocker called a cyclin dependant kinase (CDK) inhibitor. These are the drugs abemaciclib, palbociclib or ribociclib

How does capivasertib and fulvestrant work?

Capivasertib is a type of targeted treatment called a cancer growth blocker. It blocks the growth factors that trigger the cancer cells to divide and grow.

Capivasertib works by blocking the AKT gene. This gene has many roles within the cell, in particular making cells grow and multiply. By blocking this gene it stops the process that allows cells to grow and divide. This helps to stop or slow down cancer cells developing.

Fulvestrant is a medicine that blocks the effects of the sex hormones. This can slow or stop the growth of cancer cells.

Sex hormones can stimulate some cancers to grow. These cancers are called hormone sensitive or hormone receptor positive.

Fulvestrant stops oestrogen getting to the cancer cells by blocking oestrogen receptors. This reduces the number of receptors the cancer cells have.

How do you have capivasertib and fulvestrant?

You take capivasertib as tablets. You swallow the tablets whole with a glass of water. You take the tablets with or without food. You should not crush, split, dissolve or chew the tablet.

You have fulvestrant as an injection into the muscle (intramuscular) of each buttock.

Taking your tablets

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking a cancer drug, or if you miss a dose.

How often do you have capivasertib and fulvestrant?

You have capivasertib and fulvestrant as cycles of treatment. This means you have the drugs and then a rest to allow your body to recover.

Each cycle lasts 4 weeks (28 days). You take capivasertib and fulvestrant for as long as the treatment is working, and you are not experiencing too many side effects.

Tests

You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Capivasertib can cause a high blood sugar level. So before and regularly during treatment you have your blood sugar levels checked. If you have diabetes your healthcare team will tell you what extra monitoring you may need during this treatment.

Before treatment starts you may have a blood test to check for viruses such as hepatitis B, hepatitis C, and HIV. This is called a viral screen.

It’s important for your doctor to know if you have had any of these viruses. This is because this treatment can weaken your immune system and can cause the virus to become active again (reactivation).

What are the side effects of capivasertib and fulvestrant?

Side effects can vary from person to person. They also depend on what other treatments you're having.

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects

• your side effects aren’t getting any better

• your side effects are getting worse

Early treatment can help manage side effects better.

We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.

Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Urinary tract infections (UTIs)

Tell your doctor or nurse if you think you might have a urinary tract infection. You might find it difficult to pass urine, want to go with some urgency or are going more often. There may be pain or burning when you go. You may see blood in your urine, or your urine might smell bad or look cloudy.

Breathlessness and looking pale

You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

High blood sugar levels

High blood sugar levels can cause headaches, feeling thirsty and blurred vision. You have regular tests to check your blood sugar levels. You may need to check your levels more often if you have diabetes.

Less commonly the test glycosylated haemoglobin (HbA1c) might show that your average blood sugar level is high. This works out your blood sugar level over the last 2 to 3 months.

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Diarrhoea

Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a stoma , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.

Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.

Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.

Feeling or being sick

Feeling or being sick is usually well controlled with anti-sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Sore mouth

Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.

Skin problems

This treatment commonly causes skin problems such as a rash and itching. Other signs may include redness, peeling, swelling, and flaking.

Less commonly you may get dry skin.

Let your healthcare team know straight away if you notice any skin changes. They can tell you what products you can use on your skin to help.

Tiredness and weakness (fatigue)

You might feel very tired and as though you lack energy.

Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.

Pain in different parts of the body

You might have pain in the muscles, joints, bones, ligaments, tendons and nerves. Less commonly you might have back pain and pain along the sciatic nerve (sciatica).

Allergic reaction

You might have an allergic reaction. Symptoms can include a skin rash, itching, flushing, breathing problems, swelling of the face and throat, and dizziness due to low blood pressure. Rarely, some allergic reactions can be life threatening.

Tell your nurse or doctor straightaway if you notice any of these symptoms or go straight to accident and emergency (A&E) if you have a reaction.

Hot flushes and sweats

We have some tips for coping with hot flushes and the possible treatments for men and women. Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe you some medicines.

Liver changes

You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes.

Rarely this treatment can cause inflammation of the liver or it might stop your liver from working properly.

You have regular blood tests throughout your treatment so your doctor can check this.

Soreness and swelling around the injection site

Tell your nurse if you notice any signs of redness or irritation around the injection site. Rarely you might have some bleeding or bruising at the injection sites.

This can last for 1 or 2 days after the injections.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

• taste changes

• indigestion -symptoms include heartburn, bloating and burping

• inflammation of the lining of the tissues (mucosa). This can affect any part of the body, such as the digestive tract. Symptoms include pain, redness, bloating, diarrhoea, feeling or being sick

• high levels of a waste product made by the muscles (creatinine). Your kidneys remove this from the blood and get rid of it in the urine. You have blood tests to check the levels of creatinine

• headaches

• increased risk of blood clots that can be life threatening; signs are pain, redness and swelling where the clot is. Feeling breathless can be a sign of a blood clot in the lung. Contact your advice line or doctor straight away if you have any of these

• bleeding from the vagina. Rarely you might have a thick, white discharge, or a yeast infection called thrush

• low levels of platelets that can cause bruising, bleeding gums or nosebleeds

• numbness, pain or tingling in your fingers or toes

Possible rare and long term side effects

Capivasertib is a new drug in cancer treatment. So there is limited information available at the moment about possible rare and longer term effects that it may cause. Tell your doctor if you notice anything that is not normal for you.

Coping with side effects

We have more information about side effects and tips on how to cope with them.

Read more about how to cope with side effects

What else do you need to know?

Other medicines, food and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Loss of fertility

It is not known whether this treatment affects fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Pregnancy and contraception

This treatment might harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment. Talk to your doctor or nurse about effective contraception before starting treatment.

Women must not become pregnant for at least 2 years after the end of treatment. Men should not get someone pregnant for at least 16 weeks after treatment.

Breastfeeding

It is not known whether these drugs come through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

Immunisations

Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having.

Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, and yellow fever.

You can usually have:

• other vaccines, but they might not give you as much protection as usual

• the flu vaccine (as an injection)

• the coronavirus (COVID-19) vaccine

Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.

Contact with others who have had immunisations

You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your immune system is weakened.

Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.

Read more about immunisations and cancer treatment

More information

For further information about each drug and the possible side effects go to the electronic Medicines Compendium (eMC) website. You can find patient information leaflets for each drug on this website.

eMC webste

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Report a side effect to the MHRA