Evaluating the impact of atezolizumab on febrile neutropenia occurrence in patients with NSCLC undergoing chemotherapy in Japan: a real-world post-marketing database study

Background: Febrile neutropenia (FN) is a recognised adverse event associated with chemotherapy. This study investigates the impact of atezolizumab, an immune checkpoint inhibitor, on the incidence of FN in patients with non-small cell lung cancer receiving concurrent chemotherapy in Japan.

Methods: This post-marketing database study was conducted using data from patients with non-small cell lung cancer provided by Medical Data Vision Co., Ltd. covering April 2008 to present. The primary outcome measured was FN incidence, and its causal association with atezolizumab use was examined by comparing the atezolizumab plus bevacizumab plus carboplatin plus paclitaxel [ABCP])-containing regimen to the BCP control group. The data period was from 1 September, 2015, to 31 December, 2021, including approval date of this drug, 21 December, 2018.

Results: The database identified 301 subjects for the ABCP regimen (exposure) group, 44 for the BCP regimen (cohort design control) group during the same period, and 207 for BCP regimen (historical cohort design control) group before the approval of atezolizumab. For historical cohort design, the incidence and adjusted incidence ratios of febrile neutropenia in the exposure group to the control group were 6.13 (95% CI 2.78-13.49) and 8.19 (95% CI 3.79-25.33), respectively. Sensitivity analysis showed FN occurred in 17% (52/301) of the exposure group, 4.5% (2/44) of the cohort design control group, and 3% (7/207) of the historical cohort design control group.

Conclusions: The incidence of FN was higher in the exposure group. Considering the study results, special caution is needed for FN occurrence in patients receiving atezolizumab.