Epcoritamab (Tepkinly®)

You have epcoritamab as an injection under the skin (subcutaneously).

During a course of treatment, you will meet someone from your cancer team, such as a:

• cancer doctor
• specialist nurse
• specialist pharmacist.

This is who we mean when we mention doctor, nurse or pharmacist in this information.

During your course of treatment, you will have regular blood tests. This is to check that it is safe for you to have treatment.

You will meet with a doctor, nurse or pharmacist before you have treatment. They will talk to you about your blood results and ask how you have been feeling. If your blood results are okay, the pharmacy team will prepare your targeted therapy.

For the first 3 months, you have epcoritamab once a week.

For the next 6 months, you have it once every 2 weeks.

After that, you have it once a month.

Epcoritamab may cause a side effect called Cytokine Release Syndrome (CRS). We have more information about this in our section about very common side effects.

To reduce and manage CRS:

• In your first month of treatment, some of your injections may be given during a stay in hospital. This means your cancer team can monitor you closely for any side effects and treat them quickly.
• You have steroids and other drugs before and after your first treatments. This can help to reduce any CRS symptoms.

After your first treatments, you may be able to have epcoritamab in a day unit or clinic as an outpatient. Your cancer team will explain what to expect. If you have had CRS symptoms, you may need to have steroids and other drugs before and after every injection.

You usually keep having this treatment as long as it is effective and the side effects are manageable. Your cancer team will discuss your treatment plan with you.

They may also give you anti-sickness drugs and other medicines to take home. Take all your capsules or tablets exactly as they tell you to.

This treatment makes the body release large amounts of cytokines. Cytokines are chemical messengers that help your immune system protect the body from infection and illness.

You may have flu-like symptoms. These can range from mild to severe. You may need treatment and close monitoring until the symptoms improve. Some people will be monitored and treated in intensive care.

CRS is most likely to happen the first few times you have this treatment. But it can happen later. If you have any of the following symptoms at any time during this treatment, contact the hospital straight away on the 24-hour number:

• a high temperature
• chills
• a fast heart rate
• dizziness or light-headedness
• a headache
• muscle or joint pain
• diarrhoea
• feeling sick or being sick (vomiting)
• difficulty breathing or shortness of breath.

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is called neutropenia.

An infection can be very serious when the number of white blood cells is low. Your doctor may give you antibiotics and other drugs to take during this treatment. These may help reduce your risk of getting an infection. 

But it is still important to get any infection treated as soon as possible. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

• a temperature above 37.5°C 
• a temperature below 36°C
• you feel unwell, even with a normal temperature
• you have symptoms of an infection.

Symptoms of an infection include:

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

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

Your white blood cell count 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.

You may be given a drug called G-CSF. This encourages the body to make more white blood cells. You have it as a small injection under the skin.

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 feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

• nosebleeds
• bleeding gums
• heavy periods
• blood in your urine (pee) or stools (poo)
• tiny red, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. You may need a drip to give you extra platelets. This is called a platelet transfusion.

The skin in the area that was injected may become:

• painful
• swollen
• itchy
• red, if you have white skin
• darker, if you have black or brown skin.

Tell your doctor, nurse or pharmacist if this happens. Painkillers may help.

Feeling tired is a common side effect of this treatment. Tell your cancer team if you find this difficult to manage or if it gets worse. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired.

If you feel sleepy, do not drive or use machinery.

You may get pain in your tummy (abdomen), or have indigestion. Your doctor, nurse or pharmacist can give you advice or treatment to help. Contact the hospital straight away on the 24-hour number if your symptoms do not go away, or get worse.

Your doctor, nurse or pharmacist will prescribe anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to, even if you do not feel sick. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible. They will give you advice. They may change your anti-sickness treatment. Let them know if you still feel sick.

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

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

• taking anti-diarrhoea medicines 
• drinking enough fluids to keep you hydrated and to replace lost salts and minerals
• any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

This treatment can cause a build-up of fluid in the body. This will slowly get better after treatment ends. Contact the hospital on the 24-hour number if you:

• are gaining weight 
• have swelling in your face, legs or ankles.

They can give you advice and treatment to help.

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• throbbing pain or swelling in a leg or arm
• reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
• suddenly feeling breathless or coughing.

Always call 999 if you have:

• chest pain
• difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

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

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax^®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use 
• how long after treatment you should continue to use contraception. 

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

Your doctor, nurse or pharmacist 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.

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

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.