Trastuzumab

Summary

Trastuzumab is an anticancer monoclonal antibody that targets HER2. Clinically, it’s used to treat breast cancer and gastric cancers that overexpress HER2. A key side effect to remember is dilated cardiomyopathy, which is often reversible after stopping the drug.

Key Points

• Trastuzumab
  • Mechanism
    • Anticancer monoclonal antibody
      • Works against extracellular targets to neutralize them or promote immune system recognition (e.g. ADCC by NK cells)
      • Eliminated by macrophages (not cleared by kidneys or liver)
    • Targets HER2
      • Trastuzumab is a targeted antibody against HER2 (human epidermal growth factor receptor 2), a protein that is overexpressed in certain types of cancer cells
  • Clinical Use
    • Treats breast cancer
      • Commonly used to treat HER2-positive breast cancer, which accounts for about 20-25% of all breast cancer cases
    • Treats gastric cancer
      • Used for treatment of HER2-positive metastatic gastric or gastroesophageal junction adenocarcinoma
  • Side Effects
    • Dilated cardiomyopathy (often reversible)
      • Condition where the heart muscle becomes weakened and enlarged. This can lead to heart failure symptoms such as shortness of breath, fatigue, and swelling in the legs.
      • Often reversible, meaning that the heart function can improve or return to normal after stopping the treatment