White blood cell kinetics in patients with gynecologic cancer receiving mecapegfilgrastim prophylaxis: A multicenter real-world study.

Abstract

e17502 Background: Some studies have indicated that using granulocyte-colony stimulating factor (G-CSF) following chemotherapy in patients with solid tumors may increase the risk of excessive white blood cell (WBC) elevation. In this real-world study, we aimed to assess the changes in WBC counts after prophylactic administration of 6 mg mecapegfilgrastim (a long-acting G-CSF) in multiple chemotherapy cycles among Chinese gynecological cancer patients, with a particular focus on those with low body weight (≤50 kg). Methods: A multicenter prospective cohort study was conducted involving gynecological cancer patients who received at least two consecutive chemotherapy cycles with mecapegfilgrastim 6 mg (administered 24 hours post-chemotherapy) between October 2019 and November 2021. Absolute WBC and absolute neutrophil counts (ANC) were recorded at baseline and on the 7th and 14th days of each cycle. Results: A total of 256 gynecological cancer patients completing 2-4 treatment cycles, including 86 with cervical cancer, 136 with ovarian cancer, and 34 with endometrial cancer, were analyzed. Of them, 58 had a pre-chemotherapy body weight of ≤50 kg, and 198 had a body weight of >50 kg. The majority of patients received taxane-based chemotherapy regimens with a cycle duration of ≥14 days. For day 7 post-chemotherapy WBC counts, data were collected from 535 cycles, including 125 cycles in the ≤50 kg group and 410 cycles in the >50 kg group. Elevated WBC counts (>10.0×10^9/L) were observed in 56 cycles (44.8%) in the ≤50 kg group and 177 cycles (43.2%) in the >50 kg group. On day 14 post-chemotherapy, data from 505 cycles, comprising 115 cycles in the ≤50 kg group and 390 cycles in the >50 kg group, indicated elevated WBC counts in 27 cycles (23.5%) in the ≤50 kg group and 63 cycles (16.2%) in the >50 kg group. In the ≤50 kg group, 3 cases (5.2%) experienced an ANC <0.5×10^9 /L, with no febrile neutropenia observed. In the >50 kg group, 11 cases (5.6%) experienced an ANC <0.5×10^9 /L, with 1 patient (0.51%) experiencing febrile neutropenia. Conclusions: In patients with low body weight (≤50 kg), the administration of 6 mg mecapegfilgrastim effectively stabilizes WBC elevation, exhibiting a favorable safety and efficacy profile. This regimen ensures the timely and appropriate progression of patients to subsequent cycles of chemotherapy. WBC counts in patients. [Table: see text]