Efbemalenograstim alfa for primary prophylaxis of chemotherapy-induced neutropenia in patients with ovarian and cervical cancer: A single-arm, multicenter clinical trial.

e17566 Background: Neutropenia is the most common hematological toxicity of myelosuppressive chemotherapy. To observe the efficacy and safety of efbemalenograstim alfa in the prevention of absolute neutrophil count (ANC) reduction after chemotherapy in Ovarian cancer(OC) and Cervical cancer(CC) patients at risk of platinum-containing chemotherapy with risk factors in febrile neutropenia (FN). Methods: This study was a single-arm, multicenter clinical trial(NCT06251947). A total of 83 patients would be enrolled, including 55 patients with primary epithelial OC (including fallopian tube cancer and primary peritoneal cancer) and 28 patients with primary or recurrent/metastatic CC in the first-line setting. All patients were scheduled to receive 3-6 cycles of chemotherapy regimen (Paclitaxel + Carboplatin/Cisplatin ± Bevacizumab). Efbemalenograstim alfa should be administered subcutaneously, 20mg per injection, within 24-48 hours after the completion of each chemotherapy cycle. The primary endpoint was the duration of grade 3 (ANC<1×10 9 /L) or 4 (ANC<0.5×10 9 /L) neutropenia in cycle 1. The safety was evaluated. Results: As of 23 December 2024, 53 patients were enrolled (Age: 56.0, 48.5-62.5), including 45 patients with OC and 8 patients with CC. The number of patients with complete data for at least one cycle of AE was 52 (OC:44, CC:8). In the OC patient cohort, the incidence of grade 3-4 neutropenia was 15.56% (7/45) with an initial duration of 1.86 days. The duration of initial grade 3-4 neutropenia in the 2 CC patients was 2.50 days. Of the 43 patients with complete blood count (CBC) data, 22 patients (CC: 3, OC: 19) reached ANC nadir on day 7 of the first cycle. Of the 37 OC patients with complete blood count data, 11 patients who reached a low on day 3 of the first cycle had a neutrophil count of 3.67 (2.97-4.95) and 19 patients who reached a low on day 7 of the first cycle had a neutrophil count of 2.76 (1.39-8.00). Treatment-related adverse events (TRAEs) in this study were predominantly grade 1 and 2, included anaemia, nausea, vomiting, thrombocytopenia and leucopenia. Grade 3 and 4 adverse reactions included thrombocytopenia, anaemia and leucopenia. In addition, no discontinuations due to TRAEs or deaths were reported during the study period. Conclusions: A single fixed dose of 20 mg of efbemalenograstim alfa was proved to be safe and effective in reducing chemotherapy-induced neutropenia and its complications in patients who received Chemotherapy. Efbemalenograstim alfa provides an alternative for patients with chemotherapy-induced neutropenia. Clinical trial information: NCT06251947 .