Pembrolizumab is an immunotherapy medication containing the active constituent pembrolizumab. It is used to treat skin, lung, bladder, stomach, liver, gallbladder, cervix, kidney, colon, rectum, esophagus, breast, and uterus cancers. It is used to treat head and neck cancer and classical Hodgkin lymphoma (a type of blood cancer). Cancer is a disorder in which cells multiply uncontrolled and abnormally. It can lead to durable responses and improved survival in some patients with advanced cancer. It can improve overall survival in patients with several types of advanced cancer. However, not all patients respond to it, and some may experience side effects. It is not recommended for adolescents and children under 18 years of age, except for children with classical Hodgkin lymphoma aged three years and older. 

Pembrolizumab is administered intravenously, usually in a hospital or clinic setting. The treatment is typically given every three to four weeks, and the number of treatment cycles depends on the type of cancer, the stage of cancer, and the patient's response to the drug. It was first approved by the U.S. Food and Drug Administration (FDA) on August 5, 2016, to treat head and neck squamous cell carcinoma. As with any cancer treatment, the decision to use it will depend on several factors, including the type and stage of cancer, the patient's overall health, and other treatments the patient has received. Patients considering pembrolizumab should discuss the potential risks and benefits with their healthcare provider.

It was first approved for treating head and neck advanced squamous cell carcinoma. Afterward, it is used to treat several other types of cancer, including non-small cell lung cancer, classical Hodgkin lymphoma, urothelial carcinoma, gastric cancer, head and neck squamous cell carcinoma, melanoma, cervical cancer, and primary mediastinal large B-cell lymphoma.

Pembrolizumab is a medication that is administered by a healthcare professional, typically in a hospital or clinic setting. The medication is given as an intravenous (IV) injection by healthcare professional. The dosage and frequency will depend on the type and stage of the cancer, as well as the patient's overall health and response to the medication. The medication is typically given every three to four weeks, and the number of treatment cycles varies with the type and staging of cancer and the patient's response to the drug. During the infusion, the patient will be monitored by a healthcare professional for any potential side effects or reactions to the medication. The infusion usually takes around 30 minutes to 1 hour to complete, and the patient can usually go home afterward.

Some of the more serious side effects that have been reported with pembrolizumab include pneumonitis (inflammation of the lungs), hepatitis (inflammation of the liver), colitis (inflammation of the colon), hypothyroidism or hyperthyroidism (changes in thyroid function), adrenal insufficiency (decreased adrenal function), and type 1 diabetes (autoimmune destruction of insulin-producing cells). 

In addition to the more serious side effects, pembrolizumab can also cause common side effects such as fatigue, nausea, loss of appetite, diarrhea or constipation, skin rash or itching, headache, muscle or joint pain, cough or shortness of breath, fever or chills, and low blood cell counts. These side effects can vary in severity and frequency among patients.

Pembrolizumab can cause immune-mediated adverse reactions, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, and other immune-mediated adverse reactions. These adverse reactions can be serious or life-threatening and may occur even after discontinuing it. It is associated with the risk of infusion reactions, including fever, chills, rash, hypotension, wheezing, and shortness of breath. These reactions can be severe and require immediate medical attention. It can also cause fetal harm if administered during pregnancy.  Pembrolizumab also carries the risk of immune-mediated colitis (inflammation of intestine), which can cause severe diarrhea, abdominal pain, and gastrointestinal perforation. in some cases hepatitis (liver inflammation). Patients should report any symptoms of colitis to their healthcare provider immediately.

Patients receiving pembrolizumab should take several precautions to ensure safe and effective treatment. First and foremost, they should inform their healthcare provider of any current medications, medical conditions, or allergies before starting treatment with pembrolizumab. This will help the healthcare provider determine if pembrolizumab is safe for the patient and adjust the treatment plan as needed. Pembrolizumab may interact with other drugs, including immunosuppressive agents, such as corticosteroids, which may reduce the effectiveness of pembrolizumab, so patients should avoid taking these medications together. Patients receiving it should also avoid live vaccines during treatment, as the drug may affect their effectiveness. Women of reproductive potential should use effective contraception during treatment and four months after the last dose of pembrolizumab. Patients should also seek immediate medical attention if they experience signs or symptoms of a serious infusion reaction, such as fever, chills, rash, hypotension, wheezing, or shortness of breath.

It is important to follow the healthcare provider's instructions carefully when receiving treatment with pembrolizumab or any other medication. One of the most essential things you can do is attend all scheduled appointments. It will allow your healthcare provider to monitor your progress, check for any potential side effects, and adjust your treatment plan as needed. women should avoid conceiving and breastfeeding during treatment. It is important to report any symptoms or side effects to your healthcare provider as soon as possible. It can help ensure that any issues are addressed promptly and effectively. Maintaining a healthy lifestyle while receiving treatment with pembrolizumab is also essential. It includes eating a balanced diet, getting enough rest, and engaging in regular physical activity, as the healthcare provider recommends. Finally, being patient and staying positive throughout the treatment process is essential. Staying positive and optimistic can help you stay motivated and focused on your recovery.

1. Merck Sharp & Dohme (UK) Limited, European Medicines Agency (emc), [ Revised on Nov 2022], [ Accessed on 30th March 2023], https://www.ema.europa.eu/en/documents/procedural-steps-after/keytruda-epar-procedural-steps-taken-scientific-information-after-authorisation_en.pdf
2. Merck, U.S. Food and Drug Administration, Highlights of Prescribing Information: Pembrolizumab, [Last revised 2023], [Accessed on 30th March 2023], https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/125514s128lbl.pdf
3. Merck & Co., Inc, ASCO (American Society of Clinical Oncology) - Information on pembrolizumab {Last Revised June 2022], [Accessed on 30th March 2023], https://www.nccn.org/search-result?indexCatalogue=nccn-search-index&searchQuery=pembrolizunab
4. Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 13th Edition, 2018, 1026

The drug information on this page is not a substitute for medical advice. It is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you can receive this treatment.