Final results of a multi-center, double-blind, randomized, placebo-controlled phase II study to assess the efficacy of MAGE-A3 immunotherapeutic as adjuvant therapy in stage IB/II non-small cell lung cancer (NSCLC)

Abstract

7554 Background: After complete resection, about 50% of patients with stages IB-II NSCLC disease die within 5 years. Adjuvant chemotherapy improves overall survival at the expense of substantial toxicity. Activity of MAGE-A3 immunotherapeutic (i.e. recombinant MAGE-A3 protein and a potent GlaxoSmithKline adjuvant) was previously demonstrated in metastatic melanoma. As about 35% of NSCLCs express MAGE-A3 antigen, post-operative MAGE-treatment may be a tumor-specific, well tolerated, and effective adjuvant therapy. Methods: Patients with completely resected, MAGE-A3 (+), stage pIB or pII were randomly assigned to postoperative MAGE-A3 or placebo (2:1), with 5 administration at 3-week intervals, followed by 8 administrations every 3 months. Randomization was stratified for stage (IB vs. II), histology (squamous vs. other), and lymph-node (LN) procedure (sampling vs. dissection). Primary endpoint was disease-free interval (DFI); other endpoints were safety, disease-free survival (DFS), and overall survival (OS). This exploratory Phase II study was designed to detect a clinically relevant HR with a 10% one-sided a. Results: 182 patients (122 stage IB, 60 stage II) from 59 centers in 14 countries were randomized over 2 years: Median age 63 (45–81); 87% male; 65% squamous cell carcinoma; 65% lymph-node dissection. After a median follow-up of 28 months, 67 recurrences and 45 deaths were recorded. Group comparisons of DFI, DFS and OS gave respectively a hazard ratio (HR) of 0.74 (95% CI 0.44–1.20, p=0.107), 0.73 (95% CI 0.45–1.16) and 0.66 (95% CI 0.36–1.20) in favor of the MAGE-A3 group. Overall, treatment was well tolerated, with excellent protocol compliance. Subset analysis also suggests that LN dissection may have an effect on survival. Conclusions: The final analysis of this randomized phase II study shows a positive trend for activity of MAGE-A3 treatement in NSCLC with a relative improvement of DFI and DFS of 27%. Further phase III evaluation is planned. This study also suggests that complete lymph-node dissection may have an effect on survival and should be confirmed prospectively. [Table: see text]