How it is administered

Pembrolizumab is given as an intravenous (IV) infusion. This means it is delivered directly into your bloodstream through a vein, usually in your arm, over a period of about 30 minutes. The medication comes as a clear to slightly opalescent, colorless to slightly yellow solution in vials containing 100 mg in 4 mL. The typical dosing schedule is either every 3 weeks (200 mg) or every 6 weeks (400 mg), depending on your treatment plan and your doctor’s recommendation.

How it works

Pembrolizumab is a type of immunotherapy called a "checkpoint inhibitor." It is a monoclonal antibody that targets the PD-1 receptor on T cells, which are a part of your immune system. Normally, when PD-1 binds to its ligands (PD-L1 or PD-L2), it acts as a brake to prevent T cells from attacking healthy cells. However, some cancer cells use this pathway to hide from the immune system.

Pembrolizumab blocks the PD-1 receptor, preventing it from interacting with PD-L1 and PD-L2. This releases the brake on T cells, allowing them to recognize and attack cancer cells more effectively. By boosting the body's immune response against cancer, pembrolizumab can help slow or stop the growth of tumors in certain blood cancers and other types of cancer.

Who Should take it

Pembrolizumab is approved for use in several types of cancer, including certain blood cancers. For blood cancers, it is specifically indicated for adults and children with relapsed or refractory classical Hodgkin lymphoma (cHL) and for adults and children with refractory primary mediastinal large B-cell lymphoma (PMBCL) or those who have relapsed after two or more prior lines of therapy.

While pembrolizumab is not specifically approved for Peripheral T-Cell Lymphoma (PTCL), it may be considered in certain situations as part of clinical trials or off-label use if other treatments have not worked. Your doctor will determine if pembrolizumab is appropriate for you based on your specific diagnosis, previous treatments, and overall health.

Who should not take it

There are no absolute contraindications listed for pembrolizumab, but it should be used with caution in certain situations. Patients who have had severe allergic reactions to pembrolizumab or any of its ingredients should not receive this medication.

Pembrolizumab may not be suitable for people with active autoimmune diseases, those who have had organ transplants, or those who are pregnant, as it can cause immune-mediated side effects or harm to an unborn baby. If you have a history of severe immune-related adverse reactions or are taking immunosuppressive medications, discuss these with your doctor before starting pembrolizumab.

Commonly used with

Pembrolizumab can be used alone or in combination with other cancer treatments, depending on the type of cancer. In blood cancers, it is most often used as a single agent, especially in relapsed or refractory cases. In other cancers, it may be combined with chemotherapy, targeted therapies, or other immunotherapies.

Your doctor will decide the best combination for your situation based on your cancer type and previous treatments.

Commonly tested with

Pembrolizumab has been studied in combination with various chemotherapy agents, targeted therapies, and other immunotherapies in clinical trials for different cancers. In blood cancers, it has been compared to other standard treatments such as brentuximab vedotin in classical Hodgkin lymphoma.

Ongoing research is exploring its use with other drugs to improve outcomes in different types of lymphoma and other blood cancers.