Herceptin

Herceptin is the brand name for trastuzumab, a humanized monoclonal antibody that targets the HER2/neu receptor (ERBB2). It is used to treat cancers that overexpress HER2, most notably certain types of breast cancer and gastric (stomach) cancer. By binding to the extracellular domain of HER2, trastuzumab blocks signaling pathways that promote tumor cell growth and can stimulate immune-mediated destruction of cancer cells.

In breast cancer, trastuzumab is indicated for metastatic disease and for adjuvant therapy in early-stage, HER2-positive tumors, usually in combination with chemotherapy. It is also approved for treatment of HER2-positive gastric or gastroesophageal junction cancer in combination with chemotherapy. The drug is used in various regimens, tailored to disease stage and patient factors.

Trastuzumab is administered by intravenous infusion. Dosing typically begins with a loading dose, followed by maintenance doses given every one to three weeks depending on the regimen. The exact schedule depends on whether it is used for metastatic disease or adjuvant therapy, and on concomitant chemotherapy.

Safety and monitoring considerations are important. The most significant risk is cardiotoxicity, including reductions in left ventricular ejection fraction and heart failure, particularly when used with certain other cancer drugs. Baseline and periodic cardiac function assessment (eg, echocardiography or MUGA scans) are recommended during treatment. Other common, usually manageable side effects include infusion reactions, fever, chills, nausea, and rash.

Biosimilar versions of trastuzumab have been developed and are available in many markets. Herceptin remains a widely used targeted therapy for HER2-positive cancers.