Approved for first line therapy in NSCLC and include erlotinib, afatinib, and gefitinib.
Erlotinib and geftinib are first generation TKIs.
They reversibly bind to the intracellular tyrosine kinase domain, resulting in inhibition of the autophosphorylation of the tyrosine residues.
Afatinib is a second generation TKI that irreversibly targets EGFR (HER!) as well as to HER2 and HER4.
Osimertinib is a third generation TKI.
EGFR TKIs have superior efficacy over platinum doublet chemotherapy in treatment naive patients with NSCLC with EGFR mutations.
Rash is an adverse effect specific to all agents that block the EGFR pathway, including small molecules and monoclonal antibodies.
Within weeks of starting EGFR inhibitor treatment most patients develop a rash on their face and upper trunk.
With ongoing treatment the rash can spread and itch and patients experience secondary infections with hair and nail changes.
Most cases of rash are mild, but up to 17% of patients the symptoms caused significant discomfort to lower the medication or to stop it altogether.
Disease progression with EGFR mutation TKIs for NSCLC is almost universal.
In 3 to 10% of cases patients transition to small cell lung cancer and squamous cell transformations potentially occur in up to 15% of the time after TKI failures.