This is an open-label, sing-arm, single site, phase IV clinical study. The main objective is to evaluate the efficacy of afatinib in LSQC patients with EGFR sensitive mutation, and to explore the clinical factors which might be predictive for the effectiveness in LSQC.

This is an open-label, sing-arm phase IV clinical study which will recruit about 20 patients in China.

The main objective of this study is to evaluate the efficacy of afatinib in LSQC patients with EGFR sensitive mutation, and to explore the clinical factors which might be predictive for the effectiveness in LSQC.

Target patient population:Locally advanced (IIIB) or metastatic (stage IV) immunohistochemistry (IHC)-verified Lung squamous cell carcinoma (LSQC) with EGFR sensitive mutation patients, whom previously untreated or received platinum-based doublet chemotherapy as first-line treatment with subsequent disease progression, and had to be eligible for second-line treatment.

Investigational product, the dose and administration method: Afatinib is a member of the second generation TKIs, which binds irreversibly to the erbB family of receptors. Afatinib will be administrated orally with the starting dose of 40 mg tablets, once per day. If patients can't tolerate drug related AEs with 40mg, patients can receive 30mg once per day after AEs recovered to Grade 0-1 (CTCAE 5.0).

Study assessment: The collected data include the patient's demographic characteristics, information needed to determine whether the patient is eligible (including medical history, attributes of previous and current disease, and EGFR mutation status in tumor tissues), efficacy of objective response rate(ORR), progression-free survival (PFS), overall survival (OS), and safety (including serious adverse events and dose change-induced adverse events).

Inclusion Criteria:

• Selected patients must meet all of the following standards:

  1. The patient's or his/her legal representative's has signed and dated written informed consent before any specific study procedure.

  2. The patient is above 18 years old.

  3. Locally advanced (IIIB) or metastatic (stage IV) immunohistochemistry (IHC)-verified Lung squamous cell carcinoma (LSQC) with EGFR sensitive mutation patients, whom previously untreated or received platinum-based doublet chemotherapy as first-line treatment with subsequent disease progression, and had to be eligible for second-line treatment.

  4. The patient has NOT previously received EGFR-TKI treatment.

  5. ECOG Performance Status Score is 0~2.

  6. The patient has sufficient bone marrow and organ function proved by baseline complete plasma count, plasma biochemistry and urinary biochemistry tests.

  7. Female patients of childbearing age must use adequate contraceptives, and breastfeeding is not allowed.

  8. Male patients must voluntarily to use contraceptives.

     Exclusion criteria

• Selected patients can not meet any one of the following standards:

  1. The patient has received EGFR-TKI treatment.
  2. The patient has any severe or uncontrolled systemic signs of illness, including uncontrolled hypertension, active easy-bleeding constitution, active infection, or significantly impaired function of bone marrow or organs, which researchers believe can significantly change the patient's risk/benefit balance.
  3. The patient has symptomatic central nervous system (CNS) metastases.
  4. The patient has the history of interstitial pneumonia, or radiation pneumonia which needs steroid treatment.
  5. The patient still has unrecovered toxic reaction with ≥ grade 3 (CTCAE5.0) caused by previously received treatment.