Therapeutic Response Statement (Sensitivity)
This therapeutic response statement supports the relationship that EGFR p.L858R status confers therapeutic sensitivity to Gefitinib in patients with Non-Small Cell Lung Cancer.
The U.S. Food and Drug Administration granted approval to gefitinib for the first-line 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. Gefitinib's package insert includes the following limitation of use: safety and efficacy of gefitinib have not been established in patients whose tumors have EGFR mutations other than exon 19 deletions or exon 21 (L858R) substitution mutations.
This statement is based on a regulatory approval from the Food and Drug Administration:
IRESSA is a tyrosine kinase inhibitor indicated for the first-line 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. Limitation of Use: Safety and efficacy of IRESSA have not been established in patients whose tumors have EGFR mutations other than exon 19 deletions or exon 21 (L858R) substitution mutations.