EGFR TKIs

Here’s a high-yield comparison table of EGFR TKIs tailored for oncology pharmacists, perfect for BPS exam prep:

Feature Erlotinib Gefitinib Afatinib Osimertinib
Generation 1st 1st 2nd 3rd
Mechanism Reversible EGFR TKI Reversible EGFR TKI Irreversible EGFR, HER2, HER4 inhibitor Irreversible EGFR TKI, including T790M mutation
Indication EGFR+ NSCLC (exon 19 del / exon 21 L858R) EGFR+ NSCLC (exon 19 del / exon 21 L858R) EGFR+ NSCLC (exon 19 del / exon 21 L858R) EGFR T790M+ NSCLC (resistant to 1st/2nd-gen TKIs); also 1st-line EGFR+ NSCLC
Dose 150 mg PO daily 250 mg PO daily 40 mg PO daily (adjustable) 80 mg PO daily
Key Toxicities Rash, diarrhea, hepatotoxicity, interstitial lung disease (ILD) Rash, diarrhea, hepatotoxicity, ILD Rash, diarrhea, stomatitis, paronychia, fatigue, hepatotoxicity, ILD Rash, diarrhea, QT prolongation, ILD, cardiotoxicity
Metabolism / Interactions CYP3A4 CYP3A4 CYP3A4 CYP3A4 / P-gp substrate
Monitoring / Pharmacist Considerations LFTs, skin, diarrhea, pulmonary symptoms Same as Erlotinib LFTs, renal function, diarrhea, skin care, adherence LFTs, ECG, electrolytes, renal function, skin, pulmonary symptoms
Clinical Pearls Oral therapy; rash may indicate response Oral therapy; first-gen reversible TKI Broader HER inhibition; irreversible binding; often chosen for better PFS in some EGFR+ NSCLC Active against T790M resistance mutation; good CNS penetration; irreversible
 

Quick Takeaways for BPS Exam

  1. First-gen TKIs (erlotinib/gefitinib): reversible EGFR inhibition; standard first-line EGFR+ NSCLC.
  2. Second-gen TKI (afatinib): irreversible, broader HER family inhibition; may have more GI/skin toxicity.
  3. Third-gen TKI (osimertinib): targets T790M resistance mutation, better CNS penetration, fewer rash/diarrhea side effects.
  4. Pharmacist role: dose adjustments for toxicity, monitor LFTs, skin, diarrhea, ILD, and drug-drug interactions (CYP3A4).
  5. Adherence counseling is critical as these are oral targeted therapies.
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