Incidence and Risk Factors of Infusion Reactions in Breast Cancer Patients Administered Pertuzumab Combination Chemotherapy

Abstract Purpose: Pertuzumab (Per) is a humanized monoclonal antibody used in combination with trastuzumab (Tra) in the treatment of human epidermal growth factor receptor-2 (HER2)-positive breast cancer. The administration of biologics, such as Tra and Per, frequently causes infusion reactions (IRs) with fever and chills. The purpose of this study was to clarify the characteristics of and risk factors for IRs in Tra+Per combination therapy.Methods: Between March 2013 and December 2019, 65 breast cancer patients who started Tra+Per combination therapy and 106 breast cancer patients who started Tra therapy alone were included in the study. The severity of IRs was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.Results: The incidence of IRs in the Tra+Per group was 47.7% (31/65) and was significantly higher than that in the Tra alone group (18.9%, 20/106), with a risk ratio of 2.53 (p < 0.001). The severity of IRs in the Tra+Per group (Grade 1, 9 patients; Grade 2, 22 patients) was significantly higher than that in the Tra alone group (grade 1, 16 patients; grade 2, 4 patients) (p < 0.001). Lymphocyte counts were significantly different between the IR and non-IR groups in patients receiving Tra+Per combination therapy (univariate analysis, p = 0.005; multivariate analysis, p = 0.029).Conclusion: Our study indicates that the concomitant use of Per increases the risk of IRs caused by Tra, and the risk of IRs is higher in patients with higher lymphocyte counts.