Safety of adjuvant atezolizumab after pneumonectomy/bilobectomy in stage II-IIIA non-small cell lung cancer in the randomized phase III IMpower010 trial

Abstract

Objective: Adjuvant atezolizumab is a standard of care after chemotherapy in completely resected stage II-IIIA programmed death ligand-1 tumor cell 1% or greater non-small cell lung cancer based on results from the phase III IMpower010 study. We explored the safety and tolerability of adjuvant atezolizumab by surgery type in IMpower010.

Methods: Patients had completely resected stage IB-IIIA non-small cell lung cancer (Union Internationale Contre le Cancer/American Joint Committee on Cancer, 7th Ed), received up to four 21-day cycles of cisplatin-based chemotherapy, and were randomized 1:1 to receive atezolizumab 1200 mg every 3 weeks (≤16 cycles or 1 year) or best supportive care. Adverse events and clinical characteristics were investigated by surgery type (pneumonectomy/bilobectomy or lobectomy/sleeve lobectomy) in the randomized stage II-IIIA population who received 1 or more atezolizumab dose or with 1 or more postbaseline assessment (safety evaluable) for best supportive care.

Results: Overall, 871 patients comprised the safety-evaluable randomized stage II-IIIA population. In the atezolizumab arm, 23% (100/433) received pneumonectomy/bilobectomy and 77% (332/433) received lobectomy/sleeve lobectomy. Atezolizumab discontinuation occurred in 32% (n = 32) and 35% (n = 115) of the pneumonectomy/bilobectomy and lobectomy/sleeve lobectomy groups, respectively. Grade 3/4 adverse events were reported in 21% (n = 21) and 23% (n = 76) of patients in the atezolizumab arms in the pneumonectomy/bilobectomy and lobectomy/sleeve lobectomy groups, respectively. In the atezolizumab arms of the surgery groups, 13% (n = 13) and 17% (n = 55) had an adverse event leading to hospitalization. Atezolizumab-related adverse events leading to hospitalization occurred in 5% (n = 5) and 7% (n = 23) of the surgery groups.

Conclusions: These exploratory findings support use of adjuvant atezolizumab after platinum-based chemotherapy in patients with completely resected stage II-IIIA programmed death ligand-1 tumor cell 1% or more non-small cell lung cancer, regardless of surgery type.

Keywords: IMpower010; adjuvant therapy; atezolizumab; bilobectomy; non–small cell lung cancer; pneumonectomy.