Efficacy of same-day versus next-day administration of pegfilgrastim for the prevention of chemotherapy-induced febrile neutropenia in breast cancer patients receiving dose-dense doxorubicin and cyclophosphamide: A retrospective multi-site analysis.

Introduction: Administering pegfilgrastim on the same day as chemotherapy can improve patient satisfaction through convenience and may increase the utilization of cost-effective biosimilars compared to next-day administration, but the effect on clinical outcomes with commonly used breast cancer regimens is unclear.

Methods: This multi-site, retrospective cohort study included breast cancer patients age 18 years or older who received dose-dense doxorubicin and cyclophosphamide (ddAC) and pegfilgrastim between 1 June 2016 and 31 May 2020. Pegfilgrastim was given on the same day as chemotherapy at one site and the day after chemotherapy at the other two sites. The primary endpoint compared the incidence of febrile neutropenia associated with pegfilgrastim administration timing.

Results: A total of 360 patients were reviewed (146 same-day administration and 214 next-day administration). In the same-day group 36 patients (24.6%) developed FN compared to 25 patients (11.7%) in the next-day group ( = 0.002). Same-day administration also significantly increased the incidences of additional acute care visits (11.6% vs 2.8%,  = 0.0016), grade ≥ 3 neutropenia (38.4% vs 13.6%,  < 0.0001), chemotherapy dose reductions (21.2% vs 6.1%,  < 0.0001), and antibiotic use (26.7% vs 12.6%,  = 0.001). Same-day administration did not significantly increase the rate of hospitalization (15% vs 11.2%,  = 0.36) and delay of next chemotherapy cycle by ≥1 day (8.2% vs 6.1%,  = 0.57) due to neutropenic complications.

Conclusions: Administering pegfilgrastim on the same day as ddAC led to a significant increase in neutropenic complications. This study confirms the need to administer pegfilgrastim the day after chemotherapy in breast cancer patients receiving ddAC.