Lyudmila Bazhenova, MD of the University of California, San Diego discusses the FLAURA study and improvement in PFS over standard first-line chemo. The FLAURA study compared osimertinib with the standard EGFR TKI, either gefitinib or erlotinib on newly diagnosed EGFR mutant lung cancer patients. Results showed improvement in PFS over standard first-line chemotherapy.
Which is more effective, starting with osimertinib or starting with first-line EGFR TKI and then switch to osimertinib upon progression? For newly diagnosed patients, Dr. Bazhenova recommends osimertinib to be used right away. This is because looking at the post-progression of EGFR TKI, only 60% of the patients will be eligible for osimertinib. This means that they will have a T790M mutation. So, for those who didnt develop this resistance mechanism, after 10 months of EGFR TKI, its essential to switch them to chemotherapy. However, if osimertinib is given first-line, the PFS will be stretch to 19 months before patients should undergo chemotherapy. This means delaying the chemotherapy treatment.
Aside from the improved PFS with osimertinib at first-line, the toxicity also improved. This is expected because osimertinib doesnt inhibit wild type EGFR significantly.