Targeted therapy

Targeted therapy or targeted molecular therapy refers to using drugs which are not cytotoxic but rather specifically target certain molecules to treat cancer. Targeted therapy often prolongs survival, sometimes for years, and the patient remains on the targeted therapy during this time.

Biological therapy
- = refers to biological drugs, most commonly monoclonal antibodies
- Bevacizumab – anti-VEGF
  - Inhibits vascular proliferation and therefore neovascularization
- Cetuximab – anti-EGFR
Small molecules
- = refers to small molecule drugs, which enter the cells and inhibit certain intracellular proteins
- Gefitinib, erlotinib – EGFR inhibitors
- Alectinib – ALK inhibitor
- Vemurafenib – BRAF inhibitor
  - Only works on a certain type of BRAF mutation in melanoma
  - Actually stimulates wildtype BRAF
- Sorafenib – Multi protein kinase inhibitor
  - Inhibits VEGFR, PDGFR, RAF, etc.
Common side effects
- Anti-EGFR and EGFR inhibitors
  - Acneiform dermatitis
- Anti-BRAF and BRAF inhibitors
  - Photosensitivity
  - Squamous cell carcinoma
- Sorafenib
  - Alopecia
  - Hand-foot syndrome

Immunotherapy

Immunotherapy or cancer immunotherapy refers to using drugs which indirectly stimulate the immune system to treat cancer.

Immune checkpoint inhibitors
- Most commonly used immunotherapy
- These drugs are monoclonal antibodies and therefore also technically biological drugs
- These drugs inhibit the mechanism by which cancer cells inhibit the immune system
- Anti-PD-1 – nivolumab, pembrolizumab
- Anti-CTLA-4 – ipilimumab
Vaccines
Cytokines

Because of their mechanism, they can cause a variety of severe and potentially life-threatening side effects secondary to overactivation of the immune system. The most notable are hepatitis, myocarditis, myasthenia gravis, and virtually any kind of -itis.