Nowadays, malignancies still are crucial problems of healthcare system in many aspects including efficacy of
therapeutic modalities, quality of patients’ life and cost of treatment. The understanding of genetic alterations and intracellular
pathways are very helpful to define the pathologic abnormalities specific to each cancer. Consequently, there have been
recently discovered agents which destroy the cancer cells with higher specificity than previously used agents. “Targeted
therapy” is established to call this group of drugs because its mechanism of action selectively targets on tumor-specific
abnormal cellular processes. These aimed extracellular or intracellular mechanisms are mainly divided into 3 groups; 1)
activating natural immune system directly against tumor cells, 2) inhibiting cellular proliferation, 3) inducing tumor antiangiogenesis.
The targeted drugs are currently studied to establish the appropriate regimens for cancers with or without
concurrent chemotherapy. It is important to understand and keep updated in these novel agents for better clinical outcome of
cancer patients.

Keywords: Targeted therapy, HER2 inhibitor, EGFR inhibitor, Anti-angiogenesis, Multikinase inhibitor