Would you add immunotherapy to chemotherapy for a patient with metastatic NSCLC, an atypical EGFR mutation, and PD-L1 ≥50% who has progressed on osimertinib?  

This is a difficult scenario, and there is no data to guide this. There is good evidence to suggest that patients with the classical mutations do not respond to ICIs regardless of PD-L1 expression. There is one small retrospective analysis that included 7 patients with uncommon mutations (G719X and ...

While osimertinib has shown meaningful activity in the most prevalent atypical mutations G719X, L861Q, and S768I, its efficacy is not uniform across all atypical mutations: L861Q is associated with higher response rates and longer survival, while G719X and S768I show moderate benefit. (Choet al., PM...