Abemaciclib (Verzenios)

Abemaciclib is a type of targeted cancer drug. You pronounce it as a-bee-ma-sye-klib. It is also known as Verzenios.

It is a treatment for breast cancer that has:

• spread to another part of the body (secondary or metastatic breast cancer)
• spread to the area and structures surrounding the breast, such as nearby lymph nodes , muscle and skin, but not to other parts of the body (locally advanced breast cancer)

You might also have it if you have an early breast cancer that has a high risk of coming back.

You usually have abemaciclib in combination with a type of hormone therapy. This might include fulvestrant or an aromatase inhibitor for example.

Abemaciclib is only for a type of breast cancer that is hormone receptor positive (HR+) and human epidermal growth factor receptor negative (HER2 -). You have tests on your breast cancer cells to check for this.

How does abemaciclib work?

Abemaciclib is a type of cancer growth blocker that targets the proteins cyclin dependant kinase 4 and 6 (CDK4 and CDK6) on breast cancer cells.

CDK 4 and CDK 6 are proteins that stimulate cancer cells to divide and grow.

Abemaciclib works by blocking these proteins. It aims to slow or stop the growth of the cancer.

How do you take abemaciclib?

You take abemaciclib as tablets. You take it with or without food. You swallow the tablets whole with water. Do not crush, chew or split the tablets before swallowing.

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 take abemaciclib?

You take abemaciclib twice a day. Usually in the morning and evening, about 12 hours apart.

For locally advanced or secondary breast cancer

You take abemaciclib for as long as it’s working, and you are not experiencing too many side effects.  

Early breast cancer

You usually have have abemaciclib for up to 2 years. If you live in the UK nations outside of England you might have treatment beyond 2 years.

You may stop abemaciclib if your breast cancer comes back or you are experiencing too many side effects from abemaciclib.

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.

What are the side effects of abemaciclib?

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:

Increased risk of infection

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection. 

Breathlessness and looking pale

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

Bruising, bleeding gums or nose bleeds

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

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.

Headaches

Let your doctor or nurse know if you have headaches. They can give you painkillers such as paracetamol to help.

Taste changes

Taste changes may make you go off certain foods and drinks. You may also find that some foods taste different from usual or that you prefer to eat spicier foods. Your taste gradually returns to normal a few weeks after your treatment finishes.

Dizziness

This drug might make you feel dizzy. Don’t drive or operate machinery if you have this.

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.

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.

Sore mouth

It may be painful to swallow drinks or food. Painkillers and mouth washes can help to reduce the soreness and keep your mouth healthy. 

Hair thinning or loss

You could lose all your hair or it may become thinner. This includes your eyelashes, eyebrows, underarm, leg and sometimes pubic hair. 

Your hair will usually grow back once your treatment has finished. This can take several months and your hair is likely to be softer. It can also grow back a different colour or be curlier than before.

Skin problems

Skin problems include a rash and itchy skin. Less commonly your skin might get dry. These skin conditions usually go back to normal when your treatment finishes. Your healthcare team can tell you what products you can use on your skin to help.

Tiredness and weakness

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.

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. You have regular blood tests to check for any changes in the way your liver is working.

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:

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

• watery eyes

• inflammation of the lungs that can be serious. Tell your doctor or nurse straight away if you have symptoms such as shortness of breath, cough and a high temperature

• muscle weakness

• indigestion symptoms include heartburn, bloating and burping

• nail problems such as them breaking or splitting more easily

Coping with side effects

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

What else do you need to know?

Other medicines, foods and drinks

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.

Contraception and pregnancy

It is unknown whether treatment may or may not harm a baby developing in the womb. It is important not to become pregnant while you are having treatment.

Women having abemaciclib should use 2 forms of contraception during treatment and for at least 21 days (3 weeks) after treatment finishes.

Talk to your healthcare team about contraception you can use during treatment.

Breastfeeding

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

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, yellow fever and one of the shingles vaccines called Zostavax.

You can 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 it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

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

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