Loncastuximab tesirine (Zynlonta)

Loncastuximab tesirine is a type of cancer drug called a antibody drug conjugate . You pronounce it as lon-cas-tuk-si-mab tes-i-reen. It is also called Zynlonta.

It is a treatment for certain types of non-Hodgkin Lymphoma (NHL). The types include:

• diffuse large B cell lymphoma (DLBCL)

• high grade B cell lymphoma

You might have this treatment if your lymphoma has not gone away with treatment (refractory). Or it has come back after treatment (relapsed). You must also have had 2 or more systemic treatments .

You may have it as part of a clinical trial .

How does loncastuximab tesirine work?

Loncastuximab tesirine is made up of 2 parts.

Loncastuximab is a type of targeted cancer drug called a monoclonal antibody (mAb) . It works by attaching to proteins on the surface of lymphoma cells. The protein is called CD19.

Tesirine is a type of chemotherapy drug that is attached to the mAb.

Loncastuximab tesirine works by targeting the CD19 protein on the lymphoma cells and delivering the chemotherapy to enter these cells. The chemotherapy then attacks and kills the lymphoma cells.

How do you have loncastuximab tesirine?

You have loncastuximab tesirine as a drip into your bloodstream (intravenously).

You might have treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:

• central line
• PICC line
• portacath

How often do you have loncastuximab tesirine?

You have loncastuximab tesirine as cycles of treatment. This means you have the drug and then a rest to allow your body to recover.

Each cycle lasts 3 weeks (21 days).

You have loncastuximab tesirine for as long as the treatment is working, and you are not experiencing too many side effects.

You have each cycle of treatment in the following way:

You then start a new cycle of treatment.

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.

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 loncastuximab tesirine?

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 getting an infection

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, cough, headaches, feeling cold and shivery, pain or a burning feeling when weeing, or generally feeling 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 nosebleeds

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.

Shortness of breath, cough and chest pain

Tell your doctor or nurse if you are short of breath, have a cough or chest pain. This could be due to a build up of fluid around the lungs.

Tummy (abdominal) pain 

Tell your doctor or nurse if you have this. They can check for the cause of the pain and give you medicine to help. 

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.

Constipation

Constipation is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.

Skin changes

Skin problems include reddening, skin rash and itching.

Your skin might be sensitive to sunlight, but this is less common. Don't use sunbeds or sit in the sun. It’s important look after your skin safely, this means covering up, wearing a hat and using sunscreen if you go out in the sun. 

Other skin changes include darker areas of skin and blisters. Rarely you might get pus filled bumps.

Your healthcare team can tell you what products to used on your skin to help. 

Swelling to different parts of the body

This treatment can cause swelling of hands and feet due to a build up of fluid. This is called peripheral oedema.

You might also get facial swelling or a collection of fluid in your abdomen (ascites), but this is less common.

It’s rare, but other areas of your body might collect fluid.

Let your doctor or nurse know if you have any swelling.

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.

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 throughout your treatment so your doctor can check this.

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:

• a build up of fluid in the space around the heart– symptoms of this include being short of breath, chest pain, feeling faint or lightheaded, swelling to the arms or legs

• pain or discomfort in different parts of the body

• chest pain that is not caused by problems with the heart. Or less commonly you might have inflammation of the lining around the heart (pericarditis) which causes chest pain. Go to A&E or call 999 if you have chest pain

Possible rare and long term side effects

This 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.

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 

You may not be able to become pregnant or get someone pregnant after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.    

Pregnancy and contraception 

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

Women must not become pregnant for at least 10 months after the end of treatment. Men should not get someone pregnant for at least 7 months after treatment. 

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment.

Breastfeeding

It is not known whether this treatment comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment and for 3 months afterwards.

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, 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.