Pembrolizumab

Pembrolizumab (formerly lambrolizumab, trade name Keytruda) is a humanized antibody used in cancer immunotherapy. This includes to treat melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, and stomach cancer. It is given by slow injection into a vein. Pembrolizumab (formerly lambrolizumab, trade name Keytruda) is a humanized antibody used in cancer immunotherapy. This includes to treat melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, and stomach cancer. It is given by slow injection into a vein. Common side effects include itchiness, rash, cough, fever, nausea, and constipation. It is an IgG4 isotype antibody that blocks a protective mechanism of cancer cells and thereby, allows the immune system to destroy them. It targets the programmed cell death protein 1 (PD-1) receptor of lymphocytes. Pembrolizumab was approved for medical use in the United States in 2014. In 2017 the FDA approved it for any unresectable or metastatic solid tumor with certain genetic anomalies (mismatch repair deficiency or microsatellite instability). As of 2019, pembrolizumab is used via intravenous infusion to treat inoperable or metastatic melanoma, metastatic non-small cell lung cancer (NSCLC) in certain situations, as a second-line treatment for head and neck squamous cell carcinoma (HNSCC), after platinum-based chemotherapy, for the treatment of adult and pediatric patients with refractory classic Hodgkin's lymphoma (cHL), and recurrent locally advanced or metastatic esophageal squamous cell carcinoma. For NSCLC, pembrolizumab is a first-line treatment if the cancer overexpresses PD-L1, a PD-1 receptor ligand, and the cancer has no mutations in EGFR or in ALK; if chemotherapy has already been administered, then pembrolizumab can be used as a second-line treatment, but if the cancer has EGFR or ALK mutations, agents targeting those mutations should be used first. Assessment of PD-L1 expression must be conducted with a validated and approved companion diagnostic. In 2017 the FDA approved pembrolizumab for any unresectable or metastatic solid tumor with certain genetic anomalies (mismatch repair deficiency or microsatellite instability). This was the first time the FDA approved a cancer drug based on tumor genetics rather than tissue type or tumor site; therefore, pembrolizumab is a so-called tissue-agnostic drug. If a person is taking corticosteroids or immunosuppressants, those drugs should be stopped before starting pembrolizumab because they may interfere with pembrolizumab; they may be used after pembrolizumab is started to deal with immune-related adverse effects. Women of child-bearing age should use contraception when taking pembrolizumab; it should not be administered to pregnant women because animal studies have shown that it can reduce tolerance to the fetus, increasing the risk of miscarriage. It is not known whether pembrolizumab is present in breast milk. As of 2017, the drug had not been tested in people with active infections (including any HIV, hepatitis B or hepatitis C infection), kidney or liver disease, active CNS metastases, active systemic autoimmune disease, interstitial lung disease, prior pneumonia, and people with a history of severe reaction to another monoclonal antibody.