Osimertinib (brand name Tagrisso) is a third-generation EGFR (epidermal growth factor receptor) tyrosine kinase inhibitor (TKI) used to treat non-small cell lung cancer (NSCLC) with specific EGFR mutations, including the T790M mutation. Approved by the FDA in 2015 and the European Medicines Agency in 2016, it has become a cornerstone in targeted cancer therapy.
What Is Osimertinib?
Osimertinib works by irreversibly binding to mutant EGFR, particularly the T790M mutation, which often arises after resistance to first-generation EGFR inhibitors like gefitinib or erlotinib. This mutation is common in Asian women and non-smokers. Osimertinib can cross the blood-brain barrier, making it effective for treating brain metastases in NSCLC patients.
Clinical Impact
First-Line Therapy: Osimertinib increased median overall survival to 38.6 months in the FLAURA study, while previous TKIs only improved median overall survival to 31.8 months. Compared to 44% of individuals using previous medications, 54% of patients receiving osimertinib were still alive at three years.
Adjuvant Use After Surgery: In the ADAURA study, patients with EGFR-mutant NSCLC in the early stages who were given osimertinib following surgery had a median disease-free survival of 65.8 months, which was far longer than the 28.1 months the placebo group experienced. There was a 73% decrease in the chance of death or recurrence.
Chemoradiotherapy Follow-Up: According to the LAURA study, patients with unresectable stage III EGFR-mutant NSCLC who received osimertinib had a progression-free survival of 39.1 months as opposed to 5.6 months with a placebo. Additionally, it decreased the likelihood that cancer would spread to the brain.
Dosage & Side Effects
Administration: Taken orally once daily, with or without food. Duration depends on individual response and side effects.
Common Side Effects: Diarrhea, rash, dry skin, musculoskeletal pain, sore mouth, fatigue, and cough.
Monitoring: Regular blood tests and ECGs are recommended to monitor liver and kidney function and heart activity.
Real-World Impact
Dr. Bryant Lin, a Stanford professor and lung cancer researcher, was diagnosed with stage 4 NSCLC despite never smoking. He is now undergoing treatment with osimertinib and actively sharing his journey to raise awareness about lung cancer in non-smokers.
Osimertinib represents a significant advancement in targeted therapy for EGFR-mutant NSCLC, offering improved survival rates and quality of life. Its ability to address both primary and acquired mutations, including T790M, and its efficacy against brain metastases make it a vital option in modern oncology.
If you or someone you know is considering osimertinib, consulting with a medical oncologist is essential to determine its suitability based on individual genetic profiles and health status.
Conclusion: Osimertinib in Lung Cancer Treatment
Osimertinib (Tagrisso) is a breakthrough targeted therapy that has significantly improved outcomes for patients with EGFR-mutant non-small cell lung cancer (NSCLC). Its ability to target both common and resistance-causing EGFR mutations—especially T790M—along with its effectiveness against brain metastases, makes it a preferred option in both first-line and post-progression settings.
