Daratumumab is a type of targeted cancer drug. It is pronounced dar-ra-to-moo-mab. It is also known as Darzalex.

Daratumumab is a treatment for myeloma. You might have it on its own or with other cancer drugs.

How does daratumumab work?

Daratumumab is a type of targeted cancer drug called a monoclonal antibody. Monoclonal antibodies target proteins on the surface of cancer cells. 

Daratumumab works by targeting a protein called CD38 on myeloma cells so your immune system can recognise them. The immune system can then attack and kill the myeloma cells. 

How do you have daratumumab?

You usually have daratumumab as an injection under the skin. Or you might have it as a drip into a vein (intravenously).

Injection under the skin

Daratumumab is usually given under the skin (subcutaneous injection) into the tummy (abdomen).

You might have stinging or a dull ache for a short time after this injection but it doesn't usually hurt much. The skin in the area may go red and itchy for a while.

Into the bloodstream

A small number of people might have treatment through a thin short tube (a cannula) that goes into a vein in your arm. You have a new cannula each time you have treatment.

If you have breathing problems, itching, redness or swelling during your treatment let your doctor or nurse know straight away.

How often do you have daratumumab?

You have daratumumab as cycles of treatment Open a glossary item. This means that you have the drug and then a rest to allow your body to recover.

Daratumumab is given weekly to start with and then less often as time goes on. How often you have daratumumab depends on whether you’re having it with other cancer drugs or on its own.

Daratumumab can cause an allergic reaction. So before each dose you have paracetamol, a steroid and an antihistamine drug such as chlorphenamine (Piriton).

You usually have daratumumab for as long as it is working and your side effects aren’t too bad. If you are having a stem cell transplant you will have daratumumab for a set length of time. Your doctor will discuss this with you. 


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 daratumumab?

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. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. 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, 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. 

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).

Breathlessness and looking pale

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

Reaction to the drug 

A reaction to this drug is most likely to happen in the first 48 hours of having it. Your nurse will check you regularly. Symptoms include fever, chills, chest pain, rash, vomiting, facial swelling or difficulty breathing. You have medicines before and after having the drug to try to prevent a reaction.

Tell your nurse straight away if you feel unwell while you have this drug and for a time afterwards. They will slow down or stop your drip for a while.

High temperature or chills

High temperature (fever, shivering or chills) can happen with this drug. This is because it can affect your body’s ability to control temperature. Having a fever with this drug doesn’t always mean you have an infection. But you should call your advice line, as an infection can be serious if not treated quickly.

Numbness or tingling in fingers or toes

Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Tell your healthcare team if you're finding it difficult to walk or complete fiddly tasks such as doing up buttons. 

Diarrhoea or constipation

Tell your healthcare team if you have diarrhoea or constipation. They can give you medicine to help. 

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.

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.

Difficulty sleeping (insomnia)

If you have difficulty sleeping, it can help to change a few things about how you try to sleep. Try to go to bed and get up at the same time each day and spend some time relaxing before you go to bed. Some light exercise each day may also help. 

Swollen hands and legs

You may have swelling of your hands and legs due to a build up of fluid (oedema). 

Less commonly, you might get fluid build up in the lungs (pulmonary oedema).

Cough or shortness of breath

You might develop a cough or breathing problems. This could be due to infection, such as pneumonia or inflammation of the lungs. 

Let your doctor or nurse know straight away if you suddenly become breathless or develop a cough.


You may have pain as a result of this treatment. This might include back or joint pain. Less often, people may have pain around their chest. Let your healthcare team know so they can advise you on how to reduce it.

Muscle spasms 

Let your doctor or nurse know if you have muscle spasms during or after having treatment.

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.


Tell your healthcare team if you keep getting headaches. They can give you painkillers to help.

High blood pressure 

Tell your doctor or nurse if you have headaches, nosebleeds, blurred or double vision or shortness of breath. You have your blood pressure checked regularly.

Skin rash

You might get a skin rash on this treatment. Less commonly, your skin might be dry or itchy. This usually goes back to normal when your treatment finishes. Your healthcare team can tell you what products you can use on your skin to help.

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:

  • an irregular and often fast heartbeat called atrial fibrillation - you might have a heart trace test (ECG) to check for this

  • high level of sugar in the blood

  • low levels of calcium in the blood

  • low levels of fluid in the body (dehydration)

  • inflammation of the pancreas (pancreatitis)

  • feeling faint or dizzy – do not drive or operate machinery if you feel like this

  • redness, soreness or swelling at the injection site

Rare side effects

These side effects happen in fewer than 1 in 100 people (less than 1%). 

  • hepatitis B (a viral infection affecting the liver) can flare up (reactivate) – your doctor will check to see if you’ve had this virus in the past

Coping with side effects

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

What else do I need to know?

Other medicines, foods 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.

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. 

Women should use contraception during treatment and for at least 3 months after finishing 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.


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


It is not known whether this drug comes 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.


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 Open a glossary item 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.

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