Evaluation of the efficacy of osimertinib (Tagrisso) in patients with advanced lung cancer

Osimertinib is a third-generation EGFR tyrosine kinase inhibitor (TKI) specifically designed to treat patients with non-small cell lung cancer (NSCLC) carrying EGFR-sensitive mutations or T790M-resistant mutations. The drug can effectively penetrate the blood-brain barrier and also has a good control effect on patients with brain metastases. Clinical studies have shown that osimertinib can significantly prolong progression-free survival (PFS) and overall survival (OS) in the first-line treatment of EGFR mutation-positive advanced lung cancer. Compared with first- and second-generation EGFR-TKIs, such as gefitinib and erlotinib, osimertinib has a lower incidence of drug resistance and more durable efficacy, making it a first-line standard drug recommended by current international guidelines.

In patients with advanced lung cancer, the efficacy of osimertinib is mainly evaluated based on imaging and clinical symptom improvement. Most patients can observe tumor shrinkage, pleural effusion reduction, and relief of dyspnea within 1 to 2 months after taking the drug. According to the results of large clinical trials such as AURA3 and FLAURA, the objective response rate (ORR) of osimertinib treatment can reach more than 70%, and the median progression-free survival is about 18.9 months, which is much higher than traditional chemotherapy regimens. For patients with brain metastases, the intracranial disease control rate also exceeds 90%, showing superior central nervous system penetration and durable anti-tumor activity.

Although osimertinib is highly effective, drug resistance may still occur after long-term use. Common resistance mechanisms include MET amplification, EGFR C797S mutation, and activation of other signaling pathways. When imaging progression occurs or tumor markers increase, doctors usually recommend genetic testing to clarify the type of resistance and adjust treatment strategies, such as combining MET inhibitors or chemotherapy regimens. When local lesions progress but the whole body remains stable, some patients can use local radiotherapy combined with continuing to take osimertinib to delay the spread of drug resistance and maintain disease control.
Overall, osimertinib has definite efficacy and good tolerability in patients with advanced EGFR mutant lung cancer, and is an important treatment option to extend survival and improve quality of life. Its advantages include extensive mutation coverage, outstanding brain metastasis control and low toxic and side effects. In clinical practice, efficacy evaluation should be dynamically combined with imaging changes, symptom improvement, and molecular testing results to achieve personalized and precise treatment. With continued monitoring and rational combination use, osimertinib may have greater therapeutic potential in the long-term management of advanced lung cancer.
Reference: https://www.drugs.com/