Afanat 20mg Tablets Afanat 20 contains Afatinib, an orally administered, potent, selective, and irreversible ErbB family blocker. Afatinib covalent-binds to and irreversibly blocks signaling from all homo- and heterodimers formed by the ErbB family receptors: EGFR (ErbB1), HER2 (ErbB2), ErbB3, and ErbB4. By covalently binding to the kinase domains of these receptors, Afatinib prevents receptor autophosphorylation and downstream signal transduction, leading to inhibition of tumor cell proliferation, survival, and invasive potential in ErbB-dependent tumors. Afanat 20 is 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) mutations, as well as for patients with advanced squamous NSCLC progressing after platinum-based chemotherapy.