Gefitinib

What it is and how it works

Mechanism of Action The epidermal growth factor receptor (EGFR) is expressed on the cell surface of both normal and cancer cells and plays a role in the processes of cell growth and proliferation. Some EGFR activating mutations (exon 19 deletion or exon 21 point mutation L858R) within NSCLC cells have been identified as contributing to the promotion of tumor cell growth, blocking of apoptosis, increasing the production of angiogenic factors and facilitating the processes of metastasis.

Mechanism class: Protein Kinase Inhibitors

Indications

Gefitinib tablets are 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 [ see Clinical Studies ]. Limitation of Use: Safety and efficacy of gefitinib tablets have not been established in patients with metastatic NSCLC whose tumors have EGFR mutations other than exon 19 deletions or exon 21 (L858R) substitution mutations [ see Clinical Studies ]. Gefitinib tablets are 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 gefitinib tablets have not been established in patients whose tumors have EGFR mutations other than exon 19 deletions or exon 21 (L858R) substitution mutations.

Dosage and administration (summary)

Recommended dose is 250 mg orally, once daily with or without food. Patient Selection Select patients for the first-line treatment of metastatic NSCLC with gefitinib tablets based on the presence of EGFR exon 19 deletions or exon 21 L858R mutations in their tumor or plasma specimens[ see Indications and Usage , Clinical Studies ]. If these mutations are not detected in a plasma specimen, test tumor tissue if feasible. Information on FDA-approved tests for the detection of EGFR mutations in NSCLC is available at: http://www.fda.gov/CompanionDiagnostics .

Contraindications

None. None.

Warnings and precautions

•Interstitial lung disease (ILD): ILD occurred in patients taking gefitinib tablets. Withhold gefitinib tablets for worsening of respiratory symptoms. Discontinue gefitinib tablets if ILD is confirmed. ( 2.4 , 5.1 ) •Hepatotoxicity: Obtain periodic liver function testing. Withhold gefitinib tablets for Grade 2 or higher for ALT and/or AST elevations. Discontinue for severe hepatic impairment. ( 2.4 , 5.2 ) •Gastrointestinal perforation: Discontinue gefitinib tablets for gastrointestinal perforation. ( 2.4 , 5.3 ) •Diarrhea: Withhold gefitinib tablets for Grade 3 or higher diarrhea.

Pregnancy

Pregnancy Risk Summary Based on its mechanism of action and animal data, gefitinib tablets can cause fetal harm when administered to a pregnant woman. In animal reproductive studies, oral administration of gefitinib from organogenesis through weaning resulted in fetotoxicity and neonatal death at doses below the recommended human dose ( see Animal …

Storage and supply

Gefitinib is available as 250 mg tablets. Gefitinib tablets 250 mg are round, biconvex face, brown film-coated, debossed with “QL” on one side and plain on the other side. Gefitinib tablets are supplied as: Bottles of 30 Tablets (NDC 67184-0531-1) Bottles of 500 Tablets (NDC 67184-0531-2) Blisters of 3 Cards ×10 (NDC 67184-0531-3), each carton cont…

Source: Gefitinib (Gefitinib) — US FDA prescribing information, 2023-02-22, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.