Resistance to First-line Osimertinib in EGFR-mutant NSCLC: Tissue is the Issue Available to Purchase

Matched pre-/posttreatment tissue biopsies from patients with EGFR-mutant non–small cell lung cancer demonstrate that histologic transformations, including both small-cell carcinoma and squamous transformation, are unexpectedly common among patients progressing on first-line osimertinib. The study highlights the key role of tissue testing and underscores the need for innovative therapeutic approaches to prevent, rather than treat, resistance.

See related article by Schoenfeld et al., p. 2654