Mechanisms of acquired resistance to osimertinib in EGFR T790M-Positive lung adenocarcinoma.

Heterogeneous resistance mechanisms, including EGFR mutations, bypass signaling, and transformation, emerge in EGFR T790M-positive lung adenocarcinoma after 14.2 months of osimertinib treatment.

• Why it matters: Understanding these diverse resistance pathways is crucial for developing effective follow-up therapies and improving patient outcomes in NSCLC.
• What they did: Genomic and protein analyses of 86 patients who progressed after osimertinib identified key resistance mechanisms, such as C797S mutations, MET and HER2 amplifications, PIK3CA mutations, and histological transformation, with multiple mechanisms often co-occurring.
• The result: Recognizing specific resistance patterns allows for personalized treatment strategies, potentially enhancing survival, especially by combining targeted agents or immunotherapy, as demonstrated by laboratory validation of bypass pathways like MET amplification.