An anti-PD-1 immunotherapy for certain cancers
Dostarlimab
An immunotherapy given by drip that helps the immune system attack certain cancers.
What is Dostarlimab?
Dostarlimab is a specialist immunotherapy used to treat certain cancers, including some womb (endometrial) cancers. It is an anti-PD-1 checkpoint inhibitor, which means it releases a brake on the immune system so the body's own defences can recognise and attack cancer cells. It is given as a drip into a vein in repeated cycles. Its most important risk is that the energised immune system can also attack healthy organs, causing inflammation almost anywhere in the body, such as the bowel, liver, lungs or hormone glands, so new or unusual symptoms must always be reported promptly.
Education and reference only. This is a plain-language guide to Dostarlimab — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Dostarlimab is an immunotherapy medicine used to treat certain cancers, including some types of womb (endometrial) cancer, particularly those with specific genetic features that make them respond well. It belongs to a group called immune checkpoint inhibitors. Rather than attacking cancer directly like chemotherapy, it works by helping the immune system do the job. It is given as an infusion into a vein in repeated cycles by a specialist cancer team. Treatment is supervised closely because of the distinctive way it can cause immune-related side effects throughout the body.
How it works
Cancer cells can hide from the immune system by pressing a 'brake' called PD-1 on the body's defensive T-cells, telling them to stand down. Dostarlimab blocks PD-1, releasing that brake so the immune system can recognise the cancer and attack it. This is a powerful effect, but because the same brake normally helps stop the immune system attacking healthy tissue, removing it can let the immune system inflame normal organs too. This is why immune-related side effects, which can affect almost any part of the body, are the key thing the team watches for.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist immunotherapy used in the UK to treat certain cancers, including some womb (endometrial) cancers.
Practical use
How to take Dostarlimab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Have it as a drip into a vein on the schedule your specialist cancer team arranges, attending all appointments.
- Report any new or unusual symptom promptly, such as diarrhoea, cough, breathlessness, severe tiredness, rash or yellowing of the skin, even if it seems minor.
- Carry the alert card you are given and show it to any healthcare professional you see, including in an emergency.
- Do not start steroids or new medicines for side effects yourself; let the cancer team guide treatment of any immune-related effects.
- Use reliable contraception during treatment and for the time afterwards that your team advises, and report any possible pregnancy promptly.
Weighing it up
Advantages & disadvantages of Dostarlimab
Advantages
- Harnesses the body's own immune system to attack certain cancers, including some womb cancers.
- Can give lasting benefit in cancers with the right genetic features.
- Given as a drip in repeated cycles, with a different side-effect profile from traditional chemotherapy.
Disadvantages
- Can cause the immune system to attack healthy organs, leading to inflammation almost anywhere in the body.
- Immune-related side effects can appear at any time, even after treatment ends, and some can become serious.
- Can cause infusion reactions and can harm an unborn baby.
Practical use
Good to know
The most important thing to understand about dostarlimab is that, by switching the immune system on, it can cause it to attack healthy organs, not just the cancer. These immune-related effects can appear anywhere and at any time, even after treatment has finished, and include inflammation of the bowel (causing diarrhoea), the liver, the lungs (causing cough or breathlessness), the skin, and the hormone glands such as the thyroid, pituitary or adrenal glands. Some can become serious quickly, so any new or worsening symptom, however unrelated it seems, should be reported promptly, because early treatment, often with steroids, usually settles it. Reactions during the infusion can also happen. Because it can harm an unborn baby, reliable contraception is important during treatment and for a time afterwards. Treatment is always supervised by a specialist team who give you a card and clear advice on what to watch for.
Who should not take it / use with caution
- People who have had a serious allergic reaction to dostarlimab should not have it.
- It is not used in pregnancy or while breastfeeding, as it can harm an unborn baby.
- It is used with particular care in people with active autoimmune conditions or who have had an organ transplant, under specialist judgement.
Monitoring
- Regular checks for immune-related side effects affecting any organ, before and during treatment.
- Blood tests including liver, kidney, thyroid and other hormone levels.
- Reviewing symptoms and response to treatment, with prompt action on any new problems.
Side effects
- Immune-related inflammation of organs such as the bowel, liver, lungs, skin or hormone glands, which can become serious.
- Tiredness, nausea, diarrhoea, joint or muscle aches and rash.
- Hormone-gland problems, such as an underactive thyroid, causing tiredness or weight change.
- Reactions during or shortly after the infusion, which the team watches for.
Key interactions
- Steroids and other medicines that dampen the immune system may be used to treat side effects, guided by the team.
- Tell your team about any autoimmune condition or immune-affecting medicines before starting.
- Tell your team about all your medicines, including anything bought over the counter, before and during treatment.
Available as: A solution for infusion into a vein.
Answers
Dostarlimab: frequently asked questions
What is dostarlimab used for?
It is an immunotherapy used to treat certain cancers, including some womb (endometrial) cancers, by helping the immune system recognise and attack cancer cells.
How is it different from chemotherapy?
Rather than attacking cancer cells directly, it releases a brake on the immune system so the body's own defences can attack the cancer.
Why must I report new symptoms quickly?
The energised immune system can also attack healthy organs, causing inflammation almost anywhere, so early reporting allows prompt treatment before it becomes serious.
Can side effects happen after treatment ends?
Yes. Immune-related side effects can appear during treatment or even months after it finishes, so keep reporting new symptoms and carry your alert card.
Do I need contraception?
Yes. Because it can harm an unborn baby, reliable contraception is important during treatment and for a time afterwards, as your team advises.
Authoritative sources
- BNF
- NICE CKS
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