Biomarker-Directed Phase II Platform Study in Patients With EGFR Sensitizing Mutation-Positive Advanced/Metastatic Non-Small Cell Lung Cancer Whose Disease Has Progressed on First-Line Osimertinib Therapy (ORCHARD)

Introduction: Osimertinib, a third-generation, irreversible, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), selectively inhibits both EGFR-TKI sensitizing (EGFRm) and EGFR T790M resistance mutations and has demonstrated efficacy in non-small cell lung cancer (NSCLC) CNS metastases. Most patients with EGFRm NSCLC treated with osimertinib will eventually develop resistance. ORCHARD (NCT03944772) is a phase II study aiming to characterize first-line osimertinib resistance and identify post-progression treatments.

Methods: Adults aged ≥ 18 years (Japan ≥ 20 years), with EGFRm locally advanced/metastatic NSCLC will be allocated to one of three groups after first-line osimertinib progression, based on molecular profiling from a post-progression tumor biopsy. Group A will evaluate patients with protocol-determined biomarkers of resistance treated with novel osimertinib combination therapies, Group B will evaluate patients without a detectable protocol-determined biomarker treated with non-biomarker selected therapies that are chemotherapy- or EGFR-TKI-based, and Group C (observational) includes patients with histologically transformed disease, and/or a biomarker with an available therapy not investigated in ORCHARD. Group C patients will be treated as per local practice and followed to assess overall survival. The study's platform design allows for adaptability to include emerging treatments related to novel resistance mechanisms. The primary endpoint is confirmed objective response rate (investigator assessed). Other endpoints are progression-free survival, duration of response, overall survival, pharmacokinetics and safety.

Conclusions: ORCHARD aims to characterize mechanisms of resistance to first-line osimertinib and explore treatments to overcome acquired resistance. The modular design allows for additional biomarker-directed cohorts and treatment options as understanding of osimertinib resistance mechanisms evolves.