Afatinib

What it is and how it works

Mechanism of Action Afatinib covalently binds to the kinase domains of EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4) and irreversibly inhibits tyrosine kinase autophosphorylation, resulting in downregulation of ErbB signaling. Certain mutations in EGFR, including non-resistant mutations in its kinase domain, can result in increased autophosphorylation of the receptor, leading to receptor activation, sometimes in the absence of ligand binding, and can support cell proliferation in NSCLC.

Indications

Afatinib tablets are a kinase inhibitor indicated for: • First-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have non-resistant epidermal growth factor receptor (EGFR) mutations as detected by an FDA-approved test Limitations of Use : Safety and efficacy of afatinib tablets were not established in patients whose tumors have resistant EGFR mutations • Treatment of patients with metastatic, squamous NSCLC progressing after platinum-based chemotherapy EGFR Mutation-Positive, Metastatic Non-Small Cell Lung Cancer Afatinib tablets are indicated for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have non-resistant epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations as detected by an FDA-approved test . Limitations of Use : The safety and efficacy of afatinib tablets have not been established in patients whose tumors have resistant EGFR mutations [ see Clinical Studies ] .

Dosage and administration (summary)

• Recommended dosage : 40 mg orally once daily • Renal impairment : 30 mg orally once daily in patients with severe renal impairment ( 2.4 , 8.6 , 12.3 ) • Instruct patients to take afatinib tablets at least 1 hour before or 2 hours after a meal Patient Selection for Non-Resistant EGFR Mutation-Positive Metastatic NSCLC Select patients for first-line treatment of metastatic NSCLC with afatinib tablets based on the presence of non-resistant EGFR mutations in tumor specimens [ see Clinical Pharmacology , Clinical Studies ]. 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

• Diarrhea : Diarrhea may result in dehydration and renal failure. Withhold afatinib for severe and prolonged diarrhea not responsive to anti-diarrheal agents. ( 2.3 , 5.1 ) • Bullous and exfoliative skin disorders : Severe bullous, blistering, and exfoliating lesions occurred in 0.2% of patients. Discontinue for life-threatening cutaneous reactions. Withhold afatinib for severe and prolonged cutaneous reactions. ( 2.3 , 5.2 ) • Interstitial lung disease (ILD) : Occurs in 1.6% of patients. Withhold afatinib for acute onset or worsening of pulmonary symptoms.

Pregnancy

Pregnancy Risk Summary Based on findings from animal studies and its mechanism of action [ see Clinical Pharmacology ], afatinib can cause fetal harm when administered to a pregnant woman. There are no available data on the use of afatinib in pregnant women.

Storage and supply

Afatinib tablets, 40 mg are white to off white, round, biconvex, bevel-edged, film-coated tablets debossed with “A40” on one side and “H” on the other side. They are supplied as follows: Bottle of 30 tablets NDC 31722-783-30 Afatinib tablets, 30 mg are white to off white, round, biconvex, bevel-edged, film-coated tablets debossed with “A30” on one …

Source: Afatinib (Afatinib) — US FDA prescribing information, 2026-09-03, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.