Targeted Therapy

Key Points

  • Targeted therapies block specific molecular targets (receptors, enzymes, signaling proteins) that drive cancer growth.
  • They differ from chemotherapy by selectivity — attacking tumor-specific pathways with less systemic toxicity.
  • Common classes: tyrosine kinase inhibitors (TKIs), monoclonal antibodies (mAbs), PARP inhibitors, CDK4/6 inhibitors.
  • Resistance development is a major challenge, often requiring biomarker-guided therapy selection.

Mechanism

Targeted agents interrupt cancer-specific signaling cascades (e.g., EGFR, HER2, BCR-ABL, VEGF pathways) that normal cells do not heavily depend on. Biomarker testing (tumor molecular profiling) guides agent selection.

Nursing Assessment

NCLEX Focus

Side effects are target-specific. Know the class and its associated toxicity profile.

  • Monitor for class-specific toxicities: skin rash (EGFR inhibitors), hepatotoxicity (TKIs), cardiotoxicity (HER2 agents).
  • Assess for drug interactions, particularly cytochrome P450 interactions with TKIs.
  • Evaluate patient adherence to oral TKI regimens and barriers to consistent dosing.

Nursing Interventions

  • Educate on expected vs. concerning side effects and when to notify provider.
  • Support dermatologic management for EGFR-inhibitor rash (moisturizers, sun protection).
  • Reinforce oral medication adherence strategies and missed-dose protocols.
  • Monitor laboratory parameters specific to agent class (LFTs, CBC, cardiac function).

Self-Check

  1. How does targeted therapy differ from traditional chemotherapy in mechanism?
  2. Which toxicity profiles are associated with EGFR-inhibitor and HER2-targeted agents?