Erlotinib

Erlotinib tablets are a kinase inhibitor indicated for: ; The treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations as detected by an FDA-approved test receiving first-line, maintenance, or second or greater line treatment after progression following at least one prior chemotherapy regimen. ( 1.1 ) ; First-line treatment of patients with locally advanced, unresectable or metastatic pancreatic cancer, in combination with gemcitabine.

12.1 Mechanism of Action Epidermal growth factor receptor (EGFR) is expressed on the cell surface of both normal and cancer cells. In some tumor cells signaling through this receptor plays a role in tumor cell survival and proliferation irrespective of EGFR mutation status. Erlotinib reversibly inhibits the kinase activity of EGFR, preventing autophosphorylation of tyrosine residues associated with the receptor and thereby inhibiting further downstream signaling. Erlotinib binding affinity for EGFR exon 19 deletion or exon 21 (L858R) mutations is higher than its affinity for the wild type receptor.

With Steady-state plasma equilibrium reached over 3–11 hour t½ intervals for Erlotinib residence kinetics and ~100% systemic bioavailability (Erlotinib) bioavailability, Erlotinib undergoes phase i cyp3a4, cyp1a2 hepatic clearance and subsequent renal metabolite filtration and establishes therapeutic activity over peak plasma tmax within 4 hours (erlotinib).

Standard adult regimens span 150 mg/1 Tablet, Film Coated, 100 mg/1 Tablet, Film Coated, 25 mg/1 Tablet, Film Coated, 25 mg/1 Tablet, 150 mg/1 Tablet. Prescribers screen specifically against previous anaphylactoid or exfoliative reaction attributed to erlotinib; clinical scenarios where kinase inhibitor exposure from erlotinib poses unacceptable risk, while community micro-logs most frequently note nausea (7.8% of reports), headache (7.8% of reports), dizziness (6.5% of reports).