Efficacy And Safety Of Pegfilgrastim In Prophylaxis Of Chemotherapy-Induced Neutropenia In Breast Cancer Patients.

e12511 Background: The role of secondary prophylaxis with pegfilgrastim (brand name: Jinyouli) in Chinese breast cancer patients has not been fully evaluated. We assessed the efficacy and safety of pegfilgrastim in secondary prophylaxis of chemotherapy-induced neutropenia in breast cancer patients. Methods: In the open-label, single-arm, multicenter trail, 319 patients were enrolled. Breast cancer patients who developed grades 3/4 neutropenia in the previous chemotherapy cycle were given a fixed dose of subcutaneous pegfilgrastim, 24-48 hours after receiving the same chemotherapy regimen in the subsequent cycle. A dose of 6mg/cycle was given to patients weighed ≥45kg, and a dose of 3mg/cycle was given to patients weighed <45kg. The primary end point was the incidence of grade 3/4 neutropenia and secondary end point was the incidence of febrile neutropenia (FN). Results: In patients who received prophylactic pegfilgrastim, the incidence of grade 3/4 neutropenia was reduced to 12.53% (95% CI, 9.1 to 16.7) and the incidence of FN was reduced from 6.58% (95% CI, 4.1 to 9.9) in the screening cycle to 0.94% (95% CI, 0.2 to 2.7)(Table). Among the 40 patients who still developed grades 3/4 neutropenia after receiving pegfilgrastim, the absolute neutrophil count (ANC) was not significantly different between patients with (n=10) or without (n=30) additional filgrastim treatment. The most common adverse events (AEs) associated with pegfilgrastim were bone pain and myalgia, which were prevalent in 10% to 15% of the patients. However, both AEs were mild or moderate (grades 1/2). Conclusions: Prophylactic administration of pegfilgrastim is effective and safe in reducing the risk of grades 3/4 neutropenia and FN in breast cancer patients after receiving chemotherapy. [Table: see text]