Abstract 133TiP
Background
The treatment of unresectable, locally advanced stage III non-small cell lung cancer (NSCLC) is concurrent chemoradiation therapy (CRT), followed by consolidation durvalumab. This study aims to evaluate the benefit of neoadjuvant osimertinib as an alternative therapy to this approach with the aim of reducing the radiation field.
Trial design
This investigation was a nonrandomized, open-label, single-arm, phase II prospective, proof-of-concept study. Eligible patients were treatment-naïve, nonoperable, stage III EGFR-mutant NSCLC patients. Patients received 80 mg oral osimertinib daily for 12 weeks prior to definitive radiotherapy (RT) and/or surgery. The response was assessed at week 6 and week 12. For responders, sequential definitive RT and/or surgery were planned. Nonresponders were started on standard CRT. After RT ± surgery or CRT, patients were followed for two years without adjuvant therapy. The primary endpoint was the objective response rate (ORR), with September 20, 2022 set as the cut-off for data collection. Secondary endpoints were safety and the gross tumour volume (GTV), planned tumour volume (PTV) and the percentage of total lung volume exceeding 20 Gy (V20%) before vs. after osimertinib. Exploratory analyses included assessments of the presence of plasma circulating tumour-free DNA (cfDNA) before osimertinib treatment, at weeks 6 and 12, at the end of RT, and 6 weeks post-RT.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.