Regulatory approval

Published by the Food and Drug Administration.

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 is written in the approval document as:

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.

Citation

AstraZeneca Pharmaceuticals, LP. Iressa (gefitinib) [package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/206995s004lbl.pdf. Revised May 2021. Accessed October 30, 2024.

Therapeutic response

Precision oncology relationships for therapeutic response derived from this regulatory approval.

Type	Biomarker(s)	Cancer type	Therapy(ies)
Sensitivity (+)	EGFR Exon 19 (Deletion)	Non-Small Cell Lung Cancer	Gefitinib
Sensitivity (+)	EGFR p.L858R	Non-Small Cell Lung Cancer	Gefitinib