Influence of using history of immune checkpoint inhibitor therapy for neutropenia caused by combination therapy of ramucirumab and docetaxel

Recently, pretreatment with immune checkpoint inhibitors (ICIs) has been shown to enhance the therapeutic effects of the combination therapy of ramucirumab (RAM) and docetaxel (DTX); however, its influence on the drug's side effects remains unclear. This study investigated the influence of pretreatment with ICIs on the incidence of neutropenia caused by RAM + DTX therapy in patients with non-small cell lung cancer (NSCLC). Patients with NSCLC who received RAM + DTX therapy at Gifu Prefectural General Medical Center between April 2016 and December 2020 were enrolled. Retrospective data regarding age, sex, performance status and detailed treatment history, among others, at treatment initiation were collected from the patients' electronic medical records. Additionally, data on the course number of RAM + DTX therapy, supportive therapy and blood biochemical parameters, including leukocyte and neutrocyte counts, during the treatment period were collected. We identified 41 patients receiving RAM + DTX therapy. Among the more than grade 3 adverse events caused by this therapy, neutropenia was the most common (78.1 %). Despite the fact that all previous risk factors influencing this incidence rate had corresponded, the only factor influencing the incidence rate of neutropenia more than grade 3 was ICI treatment history. A difference in the incidence of neutropenia more than grade 3 in the Kaplan-Meier curve was observed between patients with and without ICI pretreatment history (p = 0.037). The pretreatment history of ICI therapy affects the incidence of neutropenia caused by RAM + DTX therapy in patients with NSCLC.