Neoadjuvant atezolizumab + chemotherapy for resectable NSCLC: 3-year clinical update of phase II clinical trial results and translational findings.

Abstract

Introduction: Neoadjuvant chemoimmunotherapy has achieved overall survival (OS) benefit for patients with resectable non-small cell lung cancer (NSCLC). Here, we present outcomes after 3 years of follow-up from the first reported study of neoadjuvant atezolizumab+chemotherapy.

Methods: This open-label, multicenter single-arm investigator-initiated phase II study conducted at three US hospitals tested up to four cycles of atezolizumab, carboplatin, and nab-paclitaxel prior to surgery. Major pathological response (MPR, primary endpoint) was previously reported; here, we report 3-year disease-free survival (DFS), OS, and clinical characteristics of patients developing brain metastases (BM) with integrated data from tumor genomics, gene expression, and quantitative immunofluorescent measurement of immune markers.

Results: Of 30 enrolled patients, 29 were taken to the operating room. 26 underwent R0 resection, with 17 experiencing MPR (10 pCR). With a median follow-up of 39.5 months, the median OS was 55.8 months, and the median DFS was 34.5 months. Landmark OS at 36 months was 77%. Among 14 patients with recurrent disease, 6 patients had BM. Patients whose tumors had mutations in STK11 and KEAP1 did not have a significantly higher incidence of BM. Reduced copy number of STK11 and KEAP1, both residing on chromosome 19p, was observed in ~1/3 of tumors. Reduced CN of STK11 was significantly associated with worse pathological response and incidence of BM.

Conclusions: Consistent with recent phase III studies, 3-year OS data with neoadjuvant atezolizumab+chemotherapy was associated with prolonged PFS and OS. Establishing associations between STK11 and KEAP1 genomic alterations and key clinical outcomes in early-stage NSCLC requires further study.