Trastuzumab deruxtecan is a targeted therapy for the treatment of metastatic or locally advanced unresectable human epidermal growth factor receptor 2 (HER2)-positive breast cancer. It is a type of monoclonal antibody and is a novel antibody-drug conjugate (ADC). Trastuzumab deruxtecan consists of trastuzumab, a humanized monoclonal antibody that binds to the extracellular domain of HER2, and a topoisomerase I inhibitor payload, DXd. This ADC has been designed to selectively accumulate in HER2-expressing cells and to release DXd intracellularly, leading to DNA damage and cell death. Trastuzumab deruxtecan is intended for use in adult patients who have received two or more prior anti-HER2-based regimens in the metastatic setting.
Trastuzumab deruxtecan, sold under the brand name Enhertu, is a targeted therapy medication used to treat specific types of cancer [1, 2]. Here's a closer look at its key features:
Function:
- Antibody-drug conjugate (ADC): Trastuzumab deruxtecan combines two components:
- Trastuzumab, a monoclonal antibody that targets the HER2 protein on cancer cells [1].
- Deruxtecan, a potent chemotherapy drug [1].
Cancers treated:
- HER2-positive breast cancer: Approved for treating metastatic breast cancer that is HER2-positive and has not responded to other treatments [1, 2].
- HER2-low breast cancer: In some cases, may be used for HER2-low metastatic breast cancer that has progressed after prior chemotherapy [2].
- Gastric or gastroesophageal junction (GEJ) adenocarcinoma: Another potential use is for HER2-positive metastatic stomach cancer [2].
How it works:
- Trastuzumab deruxtecan works in a two-pronged attack:
- The trastuzumab component targets HER2-positive cancer cells, delivering the deruxtecan payload directly to them [1].
- Deruxtecan is a cytotoxic agent that disrupts DNA replication, ultimately killing the cancer cells [1].
Important things to know about Trastuzumab deruxtecan:
- It's typically administered intravenously (injected into a vein) by a healthcare professional [1].
- Common side effects include fatigue, nausea, vomiting, constipation, low blood cell counts, and neuropathy (tingling or numbness in hands and feet) [2].
- There can be more serious side effects, including interstitial lung disease (inflammation in the lungs), neutropenia (low white blood cell count), and left ventricular dysfunction (weakening of the heart's pumping chamber) [2]. Careful monitoring by a doctor is crucial during treatment.
- It can interact with other medications, so be sure to tell your doctor about all medications and supplements you take before starting Trastuzumab deruxtecan [2].
- Pregnancy and breastfeeding are not recommended during treatment due to potential risks to the baby [2].