Afatinib after Disease Progression with Gefitinib in Advanced Adenocarcinoma of the Lung

Abstract

Background Non‐small cell lung cancer (NSCLC) is the most common form of lung cancer and comprises 75% to 85% of all lung cancer diagnoses. Epidermal growth factor receptor (EGFR) mutation positive disease comprises 10% of patients in the USA and is higher in people of Asian ancestry. Gefitinib and erlotinib are reversible tyrosine kinase inhibitors (TKIs) approved for advanced or metastatic disease but utility is limited by the emergence of resistance. Afatinib, an irreversible TKI, is under investigation for people who have developed TKI resistance. Aim To report a case of a patient with EGFR mutation positive NSCLC who developed resistance to gefitinib and was treated with afatinib. Clinical details A 61‐year‐old female presented with history of cough, malaise and anorexia that had not resolved with antibiotics and increased doses of inhaled corticosteroid. The only other medical history of note was gastro‐oesophageal reflux disease, lupus (mild arthralgia) and irritable bowel syndrome. A CT scan showed unusual lesions throughout the lungs. Bronchial washing (left upper lobe), bronchoalveolar lavage, bronchial brushing (left upper lobe) and transbronchial biopsy were consistent with adenocarcinoma. Biopsy of a right scapular lesion confirmed metastatic adenocarcinoma of the lung. The tumour was found to be positive for an EGFR mutation. Outcomes: After 12 months of therapy, the patient experienced disease progression and afatinib was commenced. After 1 month of treatment, respiratory symptoms and energy levels began to improve. CT imaging showed stable disease. The patient is being followed up on a monthly basis. Conclusion Emerging resistance to reversible TKIs poses a significant problem. Oral irreversible TKIs such as afatinib may offer an effective treatment option with minimal lifestyle interruptions and a predictable toxicity profile.