e18064 Background: Preventing chemotherapy-induced neutropenia (CIN) is critical in locally advanced nasopharyngeal carcinoma (LA-NPC) management. Although PEG-rhG-CSF is widely used, evidence for the novel long-acting G-CSF efbemalenograstim alfa in LA-NPC remains limited. This study compares the efficacy and safety of efbemalenograstim alfa versus PEG-rhG-CSF for CIN prevention in LA-NPC. Methods: This retrospective study included stage III–IVa LA-NPC patients treated between July 2023 and April 2025. Based on the prophylactic G-CSF regimen received, patients were categorized into two groups: efbemalenograstim alfa and PEG-rhG-CSF. Propensity score matching at a 1:1 ratio was performed to balance baseline characteristics, yielding a final cohort of 126 patients (63 matched pairs). Prophylactic G-CSF was administered subcutaneously to both groups during gemcitabine plus cisplatin (GP) chemotherapy. In the induction chemotherapy (IC) phase, G-CSF was given 24 hours after gemcitabine infusion; during concurrent chemoradiotherapy (CCRT), it was administered 24 hours following cisplatin. The primary outcomes were the incidence and duration of grade 3–4 CIN. Secondary outcomes included the incidence of grade 4 CIN, febrile neutropenia (FN), changes of neutrophil count, chemotherapy completion rate, and safety. Results: Compared with PEG-rhG-CSF, efbemalenograstim alfa significantly shortened the duration of grade 3–4 CIN in the first IC cycle (1.7±0.76 days vs. 2.8±0.97 days, p=0.03) and maintained this benefit throughout subsequent IC and CCRT cycles. In the first IC cycle, the incidence of grade 3–4 CIN was 14.3% with efbemalenograstim alfa versus 19.0% with PEG-rhG-CSF (p=0.477), while the incidence of grade 4 CIN was 7.9% and 11.1% (p=0.548), respectively. The rate of FN was identical in both groups (4.7% vs. 4.7%, p=1.000). Over the entire treatment course, efbemalenograstim alfa was associated with significantly lower cumulative incidences of grade 3–4 CIN (15.8% vs. 31.7%, p=0.037) and grade 4 CIN (11.1% vs. 23.8%, p=0.032) compared to PEG-rhG-CSF. Both groups demonstrated a chemotherapy completion rate of 100%. Efbemalenograstim alfa was associated with a 6.4% lower delay rate and a 0.17-day reduction in average delay duration. It also demonstrated a superior safety profile, with significantly less bone pain (26.9% vs. 46.0%, p=0.019) and only mild-to-moderate adverse events. Conclusions: Efbemalenograstim alfa offers longer-lasting neutropenia protection than PEG-rhG-CSF in LA-NPC patients, resulting in shorter severe neutropenia, higher treatment compliance, and a better safety profile with less bone pain. These findings support its role as an effective and well-tolerated prophylactic option.
Luo et al. (Thu,) studied this question.