EGFR and head and neck squamous cell carcinoma: As an irreversible blocker of the ErbB family, afatinib monotherapy induced significantly prolonged PFS (2.6 vs. 1.7 months) versus methotrexate as second-line treatment in R/M-HNSCC patients with manageable safety profiles in the phase 3 LUX-Head & Neck 1 study.437,438 The most common serious adverse effects were afatinib-related skin rash/acne and diarrhea.