Cancer drugs A to Z list
Cemiplimab is a type of treatment. You pronounce it as seh-mip-lih-mab. It is also known as Libtayo.
It is a treatment for:
or cutaneous squamous cell carcinoma (SCC) if surgery or can’t completely remove the cancer
some people with advanced
some people with cervical cancer that have had a type chemotherapy and the cancer has come back (recurrent) or has spread to other areas of the body (metastatic)
You might have cemiplimab as part of a or with other cancer drugs.
If you are having cemiplimab for NSCLC you have it with other cancer drugs. This page is about having cemiplimab on its own.
Find out more about immunotherapy treatment
Cemiplimab is a type of called a . It stimulates the body's to fight cancer cells.
Cemiplimab targets and blocks a protein called programmed cell death 1 (PD-1). This is found on the surface of certain immune cells called . Blocking PD-1 triggers the T cells to find and kill cancer cells.
Find out more about checkpoint inhibitors
You have cemiplimab as a drip into your bloodstream.
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
You 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.
You have cemiplimab as cycles of treatment. This means that you have the drug and then a rest to allow your body to recover.
You have cemiplimab as a drip into your bloodstream over about 30 minutes. You have it once every 21 days (3 weeks). This is one cycle of treatment.
If you are having it for locally advanced or metastatic cutaneous squamous cell carcinoma (SCC) you have it for up to 2 years or 35 cycles - whichever finishes sooner. Or for as long as it works and you don’t experience too many side effects.
If you are having cemiplimab for recurrent or metastatic cervical cancer you have it for up to 96 weeks. Or for as long as it is working and you are not experiencing too many side effects.
You have blood tests before and during your treatment. They check your levels of 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 and can cause the virus to become active again (reactivation).
Side effects can vary from person to person. They also depend on what other treatment you are having.
Your doctor, pharmacist or nurse will go through the possible side effects. They will monitor you closely 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.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
You might develop a cough or breathing problems. This could be due to an infection or inflammation of the lungs (pneumonitis).
You may also have other symptoms due to an infection. These include pain in the tonsils, throat or sinuses, sneezing, a stuffy or blocked nose. You might also have a headache, muscle aches, a high temperature or generally feel unwell.
Tell your doctor straight away if you are experiencing any signs of infection.
You might be breathless and look pale due to a drop in . This is called anaemia.
You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.
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 , 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 . 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.
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 if needed.
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.
You might develop a rash or itchy skin.
Occasionally you may develop patches of thick, scaly or crusty skin. Let your doctor know about any unusual skin problems.
Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.
You might have pain in your tummy (abdomen) and musculoskeletal system. This is your bones, muscles, joints, tendons and ligaments.
Rarely this treatment can cause arthritis type pain which causes swelling and stiffness in one or more joint.
Speak to your doctor or nurse about what painkillers you can take to help with this.
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:
urinary tract infection – symptoms can include stinging, burning or pain when peeing
an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness. Some allergic reactions can develop quickly and can be life threatening. Alert your nurse if you notice any of these symptoms
changes to levels of hormones made by your gland – symptoms can include feeling tired, cold, sad, depressed, anxious. You might also have an irregular or fast heart rate (palpitations) and weight changes
a headache
a high blood pressure - symptoms can include blurred vision, nosebleeds, dizziness, headaches, shortness of breath and chest pain
numbness and tingling in fingers and toes (peripheral neuropathy)
inflammation of the kidneys – symptoms can include peeing less often, blood in your pee, cloudy pee, a high temperature, feeling sick, pain in your abdomen, swelling of your legs, ankles and feet and weight gain. You have blood tests to check for any kidney changes
sore mouth
swelling (oedema) in parts of the body such as hands, feet, face
a high temperature (fever)
inflammation of the bowel (colitis) - symptoms can include diarrhoea, passing blood when you have a poo, urgency to have a poo and tummy pain
liver problems - symptoms may include yellowing of the skin or whites of the eyes, feeling or being sick, bleeding or bruising, dark urine and pain in your abdomen. You have regular blood tests to check how well your liver is working
These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:
bruising or bleeding easily due to low levels of in the blood
heart problems including swelling of the lining of the heart and heart muscle – symptoms can include shortness of breath, chest pain, tightness in the chest, tiredness, , a cough, an irregular heartbeat, feeling faint or lightheaded and flu-like symptoms
a condition called Sjogren’s syndrome where the glands stop making fluid, this can cause dryness in parts of the body including the eyes, mouth, nose, throat and skin
muscle weakness
low levels of hormones from the – some of the symptoms include muscle weakness, tiredness, weight loss, low blood pressure, loss of appetite and feeling sick
inflammation of the lining of your stomach (gastritis) - symptoms can include pain in your abdomen, indigestion, feeling bloated and feeling or being sick
eye changes – symptoms can include discomfort, itching, redness, blurred vision and sensitivity to light
inflammation and infection of the brain and – symptoms can include a high temperature, stiff neck, pain in your joints, muscles and eyes, being sick, headache, seizure (fits), being very sleepy, difficult to wake up, balance problems and numbness
- you have regular blood tests to check on this
There isn't enough information to work out how often these side effects might happen. You might have one or more of them. They include:
your immune system treating an like a foreign body. This means your body could reject the organ
inflammation of the bladder – symptoms can include peeing more often, pain when you pee, peeing blood, having the urge to pee and pain in your abdomen
the immune system attacking the bodies tissues and blood cells - symptoms can include a swollen liver, or . You might have a skin rash, changes to your breathing, bruises, peeing problems and heart problems
We have more information about side effects and tips on how to cope with them.
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We do not list these interactions on this page. 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.
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
This drug may harm a baby developing in the womb. It is important not to become pregnant while you are having treatment with this drug and for at least 4 months afterwards.
Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner becomes pregnant while having treatment.
It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed for 4 months after your last treatment.
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
Do not have live vaccines while you’re having treatment and for up to 12 months afterwards. For some people, it may be longer than this. The length of time you need to avoid live vaccines depends on the treatment you’ve had.
Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, chickenpox, BCG, and yellow fever. You can usually have non-live vaccines. But they might not give you as much protection as usual. These include the:
flu vaccine, as an injection
coronavirus (COVID-19) vaccine
Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.
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 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.
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 and Healthcare products Regulatory Agency (MHRA) as part of their Yellow Card Scheme.
Last reviewed: 07 Oct 2026
Next review due: 07 Oct 2029
Cancer drugs have side effects and these can vary from person to person. But there are things that you can do to help you cope.
Cervical cancer is when abnormal cells in the lining of the cervix grow in an uncontrolled way. The cervix is part of the female reproductive system.
Squamous cell carcinoma (SCC) of the skin is also called cutaneous squamous cell carcinoma or squamous cell skin cancer. It is the second most common type of non melanoma skin cancer.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
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