The targeted drug used in the treatment of lung adenocarcinoma used to be called 9291, and after clinical trials, it is called Ocitinib. After Ocitinib resistance, there are immunotherapy and chemotherapy, and the treatment of lung adenocarcinoma is mainly as follows: 1. Oral drugs: after the diagnosis of lung adenocarcinoma, genetic testing is conducted first to find the appropriate mutation gene, and the corresponding targeted drugs are taken orally. Targeted drugs include first-line, second-line and third-line drugs. 9291 belongs to third-line targeted drugs, while fourth-line drugs are under clinical trial. 2. Combination therapy: chemotherapy is preferred after 9291 resistance, as well as anti-angiogenic and immunotherapy. Usually chemotherapy combined with anti-angiogenic therapy, or chemotherapy combined with immunotherapy. Some patients because of the seriousness of the disease, treatment response effect is not good, can be radiotherapy, chemotherapy, anti-angiogenic three types of drugs used in combination to control the patient’s condition. If the patient’s disease can be controlled, chemotherapy is usually given in 6-8 courses, the first 6 courses contain platinum, after 6 courses it becomes single agent chemotherapy. after 1 year, the chemotherapy can be stopped and then anti-angiogenic or immunotherapy alone, or both are used to control the change of the disease.