Gefitinib (Gefitinib, Iressa, ZD1839) is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and was the first molecularly targeted drug for lung cancer to enter clinical studies. The previous IDEAL1 and IDEAL2 studies showed better efficacy in terms of efficiency, 1-year survival and quality of life for relapsed NSCLC, and it was approved by the US FDA in 2003 as second- and third-line treatment for progressive NSCLC after DDP and/or doxorubicin l treatment, and was later called off because there was no significant benefit in survival in the gefitinib-treated group in the ISEL study. However, stratified analysis showed that gefitinib treatment prolonged TTP and median survival in oriental, female, non-smoking, lung adenocarcinoma patients. the SIGN trial also showed that gefitinib was no less effective and better tolerated than standard Tysodi second-line treatment for advanced NSCLC that had failed platinum-containing chemotherapy, so the first edition of the Chinese NCCN in 2006 made gefitinib the standard second-line treatment. Reassuringly, multiple clinical studies conducted in Asia have confirmed that gefitinib has shown superior efficacy in specific populations with advanced NSCLC, both in first-line and second- and third-line treatment. A total of 31 published reports from scholars in mainland China and Taiwan, Malaysia, Korea and Japan have confirmed remission rates of 20% with gefitinib second-line treatment, while disease control rates fluctuated between 30%-70% with a median survival time of 5-15 months. First-line treatment in highly selected populations has been shown to be effective at 40-90%. Recent analyses have shown better outcomes in patients with EGFR mutations and high copy number. The recommended dose is 250 mg (1 tablet) once daily on an empty stomach or with food. Not recommended for use in children or adolescents; safety and efficacy have not been studied in this patient population. No dose adjustment is required for patient age, weight, gender, or renal status and for patients with moderate or severe hepatic insufficiency due to tumor liver metastases. The most common adverse drug reactions (ADRs) are diarrhea, rash, pruritus, dry skin, and acne, occurring in more than 20% of cases, usually within one month of dosing, and are usually reversible. Erlotinib: Selectively and directly inhibits EGFR tyrosine kinase and reduces EGFR autophosphorylation, leading to cell growth arrest and apoptosis. Similar to gefitinib, female patients with adenocarcinoma and non-smokers, benefit more significantly from erlotinib treatment. The results of the erlotinib versus placebo comparative treatment study in BR21 showed that erlotinib prolonged the survival time of NSCLC patients who failed advanced chemotherapy, and the US therefore FDA has approved erlotinib as second-line treatment for advanced NSCLC. Further stratified analysis showed that survival was significantly prolonged in patients with high EGFR gene copy number treated with erlotinib compared to the placebo group, while survival in patients with no gene amplification was not associated with erlotinib treatment. Vandetanib (ZD6474): Also a multi-targeted tyrosine kinase inhibitor (TKI) that acts on tumor cell epithelial growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), and RET tyrosine kinase simultaneously. Results from a clinical study compared the efficacy of vandetanib and gefitinib in 168 cases of advanced NSCLC that had failed first- or second-line chemotherapy. Vandetanib significantly prolonged efficiency and PFS compared to gefitinib (8% and 1%, 11.9 weeks and 8.1 weeks, respectively; p=0.011). Another study compared the efficacy and toxicities of TXT 75 mg/m2 + vandetanib (100 mg or 300 mg) or TXT + placebo in 127 patients with stage IIIB-IV NSCLC who had failed first-line platinum-based chemotherapy. The results showed that the efficiency, disease control rate and survival of the vandetanib 300 mg group were significantly better than those of the vandetanib 100 mg group and TXT alone group (efficiency rates of 18%, 26% and 11%, respectively; disease control rates of 64%, 83% and 56% in each group; survival times of 18.7 weeks, 17.0 weeks and 12 weeks, respectively). In addition, preliminary trial results evaluating vandetanib in combination with paclitaxel (200 mg/m2) + carboplatin (AUC = 6) in first-line treatment of stage IIIB-IV NSCLC showed that vandetanib did not significantly increase adverse effects. Bevacizumab (Avastin): A recombinant humanized IgG1 monoclonal antibody synthesized against VEGF, with a mouse-derived light chain variable region that binds to VEGF and a human-derived heavy chain fixed region and most of the light chain region. The specific binding of Avastin to VEGF prevents the latter from binding to the endothelial cell surface receptors Flt-1 and KDR, which prevents VEGF from promoting the proliferation of vascular endothelial cells and intra-tumor vascularization, thus blocking the supply of blood, oxygen and other nutrients essential for tumor growth and preventing tumor growth and metastasis in vivo. In 2005, researchers at the Vanderbilt-Ingram Cancer Center reported the results of a phase I/II clinical trial of bevacizumab (Avastin) in combination with erlotinib (Tarceva) for the treatment of non-small cell lung cancer. 40 enrolled patients with non-squamous cell non-small cell lung cancer were treated with the combination of Avastin and Tarceva, and the results showed The objective response rate was 20%, with an overall median survival time of 12.5 months, compared to the usual objective response rate of about 10% for conventional chemotherapy or Tarceva alone in NSCLC, with a median survival time of between 6 and 8 months. The most common side effects in the trial were mild to moderate skin rash, diarrhea and proteinuria. The results of this study suggest the feasibility and tolerability of the combination of molecularly targeted therapeutics, and its preliminary demonstration of efficacy is encouraging and provides a basis for further exploration of the efficacy of molecularly targeted drug combinations in the treatment of tumors. The ECOG4599 trial was a phase II/III randomized trial comparing the efficacy of paclitaxel-carboplatin combination or combination with bevacizumab (Avastin) in 878 patients with advanced non-squamous cell non-small cell lung cancer (NSCLC).The ECOG4599 study enrolled a total of patients with stage IIIB and IV non-squamous NSCLC from July 2001 to April 2004, and patients Patients were randomized to two groups, one (444) given chemotherapy with paclitaxel (200 mg/m2) combined with carboplatin (AUC 6) and the other (434) given bevacizumab (Avastin, 15 mg/kg) in addition to chemotherapy, both once every 3 weeks. The primary endpoint was overall survival, and the secondary endpoints were time to disease progression and safety.