FDA Approval Summary: Atezolizumab as Adjuvant Treatment following Surgical Resection and Platinum-Based Chemotherapy for Stage II to IIIA NSCLC

On October 15, 2021, the FDA approved atezolizumab as adjucancer (NSCLC) whose tumors have programmed cell death ligand 1 (PD-L1) expression on >_1% of tumor cells (TC), as detected by an FDA-approved test. The approval was based on results from the IMpower010 trial, in which 1,005 patients with NSCLC who had completed tumor resection and cisplatin-based adjuvant chemotherapy were randomly assigned 1:1 to receive atezolizumab for 16 cycles or best supportive care. The primary endpoint of disease-free survival (DFS) as assessed by investigator was tested hierarchically in the following analysis populations: stage II-IIIA NSCLC with PD-L1 expression on >_1% of TCs (PD-L1 >_ 1% TC); all randomly assigned patients with stage II-IIIA NSCLC; and the intent-to-treat population comprising all randomly assigned patients. At the prespecified interim DFS analysis, IMpower010 demonstrated a statistically significant and clinically meaningful improvement in DFS in the stage II-IIIA PD-L1 >_ 1% TC analysis population, with an HR of 0.66 (95% confidence interval, 0.50-0.88; P 1/4 0.004) favoring the atezolizumab arm. The safety profile of atezolizumab was generally consistent with known toxicities of anti-PD-(L) antibodies. The VENTANA PD-L1 (SP263) Assay (Ventana Med-ical Systems, Inc.) was contemporaneously approved as a compan-ion diagnostic device to select patients with NSCLC who are PD-L1 >_ 1% TC for adjuvant treatment with atezolizumab. Atezolizumab is the first immune checkpoint inhibitor approved by FDA for the adjuvant treatment of NSCLC.