ESMO 2021: Patterns of Relapse From IMpower010 of Atezolizumab Versus Best Supportive Care in NSCLC
Posted: Tuesday, September 28, 2021
Enriqueta Felip, MD, PhD, of Vall d’Hebron University Hospital, Vall d’Hebron Institute of Oncology, Barcelona, and colleagues presented data from an interim analysis on the sites of relapse and subsequent therapy from the IMpower010 trial during the European Society for Medical Oncology (ESMO) Congress 2021 (Abstract LBA9). This phase III study revealed a significant disease-free survival improvement with the monoclonal antibody atezolizumab over best supportive care after adjuvant chemotherapy for early-stage resected non–small cell lung cancer (NSCLC). In addition, these researchers identified a higher relapse rate in the group given the best supportive care compared with atezolizumab but no clear difference in the patterns of relapse between the two groups.
A total of 1,005 patients with completely resected, stage IB–IIIA NSCLC received up to four 21-day cycles of chemotherapy. In addition, participants were randomly assigned to receive either 1,200 mg of atezolizumab or best supportive care up until 16 cycles, unacceptable toxicity, or disease relapse.
Among patients with PD-L1 expression, relapse occurred in 73 individuals given atezolizumab and 102 given basic supportive care. The most common sites of relapse were locoregional alone (48% vs. 41%) and distant (38% vs. 39%), distant central nervous system (12% and 17%), and locoregional and distant (11% vs. 12%). Due to relapse, most participants were treated with systemic therapy (70% vs. 67%) and radiotherapy (44% vs. 47%), followed by immunotherapy (11% vs. 35%) and surgery (16% and 11%), respectively.
The significance boundary for disease-free survival was met in all patients with stage II–IIIA disease with or without PD-L1 expression in 1% or more of tumor cells. Notably, there was a direct relationship between increasing PD-L1 expression and improving disease-free survival, with hazard ratios of 0.97, 0.87, and 0.43 for less than 1%, 1% to 49%, and 50% or more of tumor cells exhibiting PD-L1 expression, respectively.
Disclosure: For full disclosures of the study authors, visit oncologypro.esmo.org.