Evaluation of safety outcomes between nivolumab regimens with differing dosing patterns

Background Real-world safety outcomes between the two flat-dose nivolumab regimens demonstrated to be similar in a study of adjuvant nivolumab recipients for melanoma. However, this study was limited by a single oncology patient population, a small sample size, and insufficient study power. The primary objective of this study was to evaluate the incidence of immunotherapy-related adverse effects (irAEs) between nivolumab regimens with differing dosing patterns in various solid tumor patient populations. Methods Single-center retrospective cohort study of adult patients with solid tumor malignancies who received nivolumab 240 mg Q2W or 480 mg Q4W, or who were transitioned from 240 mg Q2W to 480 mg Q4W from March 1, 2018 to March 31, 2022 were selected for analysis from an electronic health record generated report. The primary endpoint evaluated was the incidence of irAEs. Secondary endpoints included the incidence of significant irAEs and reasons for treatment discontinuation. These endpoints were compared by univariate analysis between all three cohorts. A multivariate analysis was then conducted for the primary endpoint. Results Nivolumab 240 mg Q2W was associated with a statistically significant increase in the incidence of colitis whereas the 480 mg Q4W regimen was associated with a statistically significant increase in the incidence of pruritis. The incidence of irAEs was not different between the three cohorts, while the incidence of significant irAEs was higher in the 240 mg Q2W and 240 mg Q2W to 480 mg Q4W cohorts. Conclusion Clinicians ought to be aware of differences in the irAE profiles between nivolumab regimens with differing dosing patterns.