Monoclonal antibodies (-abs)

• rituximab

  • mechanism: binds to CD20-positive B cells and causes their death

  • toxicities: hepatitis B reactivation, B cell depletion

  • uses: non-Hodgkin lymphoma, autoimmune diseases (including rheumatological diseases)

  • non-Hodgkin lymphoma study: 38% cure rate with CHOP therapy; 57% with R-CHOP therapy (i.e., CHOP therapy plus rituximab). this is a difference of 20%. it does not cure, but it makes a big difference

• trastuzumab (Herceptin)

  • mechanism: targets breast cancer cells overexpressing HER2/neu

  • toxicity: cardiac

  • HER2/neu breast cancer study: half of the people who would have relapsed were saved

• bevacizumab (Avastin)

  • mechanism: attaches itself to VEGF, preventing it from binding on VEGFR; this ultimately prevents angiogenesis

  • toxicities: hypertension, hemorrhage because endothelial cells are disrupted

  • metastatic breast cancer study: most people die within a couple of years. with bevacizumab, median survival was doubled (6 months to 12 months)

Category: Pharmacology Notes