Phase II Trial Shows Osimertinib's Promise for NSCLC Patients with EGFR Exon 20 Insertion

In a phase II study, osimertinib was evaluated in patients with non-small cell lung carcinoma (NSCLC) carrying EGFR exon 20 insertions after standard chemotherapy failure. Despite demonstrating antitumor activity, the primary objective response rate was not met, with most patients experiencing disease stabilization. Median progression-free survival (PFS) was 3.8 months, and overall survival (OS) was 6.5 months. Adverse events included anemia, hypercalcemia, and pneumonia. Detection of the EGFR C797S mutation in some patients limited osimertinib's efficacy. This study underscores the need for further research into effective treatments for NSCLC with EGFR exon 20 insertions.