Adjuvant Atezolizumab After Chemotherapy May Extend OS Among Patients With PD-L1 High, Resected Stage II-IIIA NSCLC

Findings from the first interim overall survival (OS) analysis of the phase 3, open-label, IMPOWER010 trial demonstrate that adjuvant atezolizumab after surgical resection and chemotherapy may extend OS among patients with PD-L1 high, stage II-IIIA non-small cell lung cancer (NSCLC), compared with best supportive care.

In the IMPOWER010 trial, 1005 patients with PD-L1 tumor cells ≥ 50, who completed 1 to 4 cycles of adjuvant platinum-based chemotherapy were randomized on a 1-to-1 basis to receive either 1200 mg of atezolizumab, administered every 3 weeks for 16 cycles (n = 507), or best supportive care (n = 498). The disease-free survival (DFS) outcomes have previously been reported.

Enriqueta Felip, MD, PhD, Vall d’Hebron University Hospital, Barcelona, Spain, and coauthors, stated previous results “demonstrated significantly improved disease-free survival with adjuvant atezolizumab vs best supportive care following platinum-based chemotherapy in the PD-L1-positive and all stage II-IIIA [NSCLC] populations.”

In the current analysis, researchers aimed to assess pre-specified interim analysis of OS in the intent-to-treat (ITT) population. Key secondary end points included OS in stage IB to IIIA patients in the ITT population and safety in all randomized patients. Additional exploratory analyses included OS by baseline PD-L1 expression level using SP253 assay.

On April 18, 2022, with a median follow-up duration of 45.3 months, the median OS in the ITT population was unable to be estimated, however the stratified hazard ratio (HR) was 0.995. Despite being unable to estimate the median OS in the ITT population, researchers observed an OS HR of 0.95 in patients with stage II to IIIA disease, 0.71 in patients who displayed a PD-L1 ≥ 1%, and 0.43 in patients with a PD-L1 TC ≥ 50%. Additionally, the incidence of atezolizumab-related adverse events remained unchanged and no new safety signals were observed after 13 months additional follow-up.

Dr Felip and coauthors concluded, “Although OS remains immature for the ITT population, these data indicate a positive trend favouring atezolizumab in PD-L1 subgroup analyses, primarily driven by the PD-L1 TC ≥ 50% stage II-IIIA subgroup.”

Souce: 

Felip E, Altorki N, Zhou C, et al. Overall survival with adjuvant atezolizumab after chemotherapy in resected stage II-IIIA non-small cell lung cancer (IMpower010): A randomised, multicentre, open-label, phase 3 trial. Ann Oncol. Published on July 17,2023. doi:https://doi.org/10.1016/j.annonc.2023.07.001