pembrolizumab at a glance
Medicine class
Anti-PD-1 immune checkpoint inhibitor
Administration
Given by a cancer team as an intravenous infusion or subcutaneous injection, depending on the selected formulation
Important safety point
Immune-related inflammation can affect almost any organ and may begin during or after treatment
What is pembrolizumab used for?
Licensed uses represented by the selected products include treatment before or after surgery, and treatment of advanced, recurrent or metastatic disease. Eligibility varies by cancer, previous treatment, companion therapy and biomarker results.
Melanoma and non-small-cell lung cancer
Malignant pleural mesothelioma and classical Hodgkin lymphoma
Urothelial and muscle-invasive bladder cancer
Head and neck squamous-cell and renal-cell cancers
MSI-high or mismatch-repair-deficient colorectal, endometrial, gastric, small-intestinal and biliary cancers
Oesophageal, gastric and gastro-oesophageal junction cancers
Triple-negative breast, endometrial, cervical and biliary-tract cancers
Platinum-resistant epithelial ovarian, fallopian-tube or primary peritoneal cancer
How does pembrolizumab work?
Pembrolizumab binds to the PD-1 receptor on immune T cells and blocks its interaction with PD-L1 and PD-L2. This releases an immune-system checkpoint, allowing stronger T-cell responses against susceptible cancer cells; the same immune activation can also inflame healthy tissues.
pembrolizumab preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 25 mg/mL
Injection
Route: Parenteral
Strengths: 395 mg, 790 mg
How to take pembrolizumab
Pembrolizumab is prepared and administered by healthcare professionals experienced in cancer treatment. The intravenous concentrate is diluted and infused into a vein. The ready-to-use subcutaneous formulation is injected into the thigh or abdomen, avoiding damaged, sore, bruised, scarred or inflamed skin; injection sites are rotated.
Check that the prescribed intravenous or subcutaneous formulation is used because their routes and preparation differ.
Report symptoms promptly and carry the supplied patient alert card.
Food does not affect administration because pembrolizumab is not taken by mouth.
pembrolizumab side effects
Common or expected effects
- Tiredness or weakness
- Diarrhoea, nausea, abdominal discomfort or reduced appetite
- Rash, itching or dry skin
- Headache
- Cough or shortness of breath
- Muscle, bone or joint pain
- Thyroid-function changes
- Injection-site reaction with the subcutaneous formulation
Get urgent medical advice
- Immune-related lung inflammation, causing new cough, breathlessness or chest pain
- Colitis, causing frequent or severe diarrhoea, blood or mucus in stools, or abdominal pain
- Liver or kidney inflammation, sometimes detected through blood tests before symptoms appear
- Hormone-gland inflammation, including thyroid, pituitary, adrenal or insulin-producing cell disorders
- Heart, muscle or nerve inflammation, causing chest pain, palpitations, weakness, swallowing difficulty or breathing problems
- Severe blistering, peeling or ulcerating skin reactions
- Serious administration-related allergic reactions
pembrolizumab in pregnancy
Human pregnancy evidence is limited, and pembrolizumab can cross the placenta and may harm a developing baby. It should generally be avoided during pregnancy unless the specialist team considers treatment clinically necessary. People who could become pregnant should use effective contraception during treatment and for at least four months after the last administration, and should contact their oncology team promptly if pregnancy occurs.
pembrolizumab while breastfeeding
It is unknown whether pembrolizumab enters human milk, and a risk to a breastfed infant cannot be excluded. The oncology and maternity teams should decide whether breastfeeding or pembrolizumab should be stopped after weighing the benefits to the parent and child.
pembrolizumab interactions
Formal pharmacokinetic interaction studies are limited. Pembrolizumab is broken down like other antibodies, so conventional metabolism-based interactions are not expected.
Systemic corticosteroids or other immunosuppressants
Avoid routine immunosuppression before starting where possible because it may reduce pembrolizumab's immune activity; these treatments may still be required to manage immune-related toxicity or support combination therapy.
Other anticancer treatments
Combination treatment can substantially change adverse effects and monitoring requirements, so the accompanying product information must also be reviewed.
Common questions about pembrolizumab
Answers are fully visible for fast scanning and source review.
Is pembrolizumab chemotherapy?
No. Pembrolizumab is an immune checkpoint inhibitor that helps T cells recognise and attack susceptible cancer cells. It may, however, be given alongside chemotherapy or other cancer treatments.
Which cancers can pembrolizumab treat?
It has licences across several solid tumours and classical Hodgkin lymphoma. The exact use depends on cancer type, stage, previous treatment, biomarker results and whether it is being used alone or in combination.
Does pembrolizumab require a PD-L1 test?
Only for certain indications. Other uses may depend on MSI-high or mismatch-repair-deficient status, different tumour features or no biomarker requirement.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.