Which type of gene mutation lung cancer is Osimertinib (Tagressa) mainly used to treat?

Osimertinib is an oral third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) specifically targeting patients with non-small cell lung cancer (NSCLC) who carry specific EGFR mutations. Compared with the first and second generation EGFR-TKI, osimertinib has higher selectivity and ability to cross the blood-brain barrier, can inhibit primary mutations and drug-resistant mutations, and effectively delay tumor progression.

Osimertinib is mainly used to treat EGFR sensitive mutationsNSCLC, including the most common 19 exon deletion (Exon 19 del) and 21 exon L858R point mutation. Such mutations will lead to the continued activation of the EGFR signaling pathway, thereby promoting tumor cell proliferation. Osimertinib irreversibly inhibits EGFR tyrosine kinase activity, effectively blocks signal transduction and slows down tumor growth.

In addition, osimertinib is also effective for patients with T790M resistance mutations that have emerged after second-line treatment with EGFR-TKI. T790MMutation is a common drug resistance mechanism, resulting in reduced efficacy of first- and second-generation EGFR-TKI. Osimertinib can selectively bind to T790M mutated EGFR and inhibit drug-resistant tumor cells. At the same time, it has less side effects on wild-type EGFR and improves tolerance.

In clinical practice, osimertinib can be used as a first-line treatment for EGFRsensitive mutationsNSCLC or a second-line treatment for resistant mutations. Studies have shown that osimertinib can significantly prolong progression-free survival (PFS), improve quality of life, and have good efficacy in patients with brain metastases. Patients should undergo genetic testing before treatment to clarify the EGFR mutation type to ensure the accuracy and effectiveness of osimertinib targeted therapy.

Reference materials:https://www.drugs.com/