Effectiveness and safety of empegfilgrastim (Extimia®) in patients with solid tumors receiving cytotoxic therapy: final results of the DEFENDOR study

Aim. To evaluate the effectiveness and safety of Extimia® (empegfilgrastim, JSC "BIOCAD") in reducing the frequency, duration of neutropenia, the incidence of febrile neutropenia (FN) and infections caused by FN in patients with solid tumors receiving myelosuppressive therapy. Materials and methods. The paper presents the final results of a multicenter prospective observational post-marketing study of the safety and effectiveness of Extimia® (empegfilgrastim) in patients with solid tumors receiving cytotoxic therapy. For the primary prevention of FN, all patients received empegfilgrastim at 7.5 mg subcutaneously once per course of chemotherapy (CT) 24 hours after the end of CT administration. The primary endpoint included an assessment of the relative dose-intensity (RDI) of the CT courses administered. The endpoints of interest included the assessment of the RDI of CT courses by nosology and CT regimen, the frequency of dose-limiting neutropenia, and the incidence of all adverse events (AEs) in patients who received at least one dose of the study medication, including serious AEs. Results. From February 2021 to December 2022, 3218 patients with various malignancies were included in 41 study centers of the Russian Fede- ration. Of these, 3217 (99.97%) patients received at least one dose of the study drug, and 2663 (82.8%) patients were included in the RDI evaluation population according to the study protocol. The mean age in this group was 56.9 (18–84) years. RDI ≥85% was achieved in 2,415 (90.7%) patients. The mean RDI was 96.2%, with a median of 100%. FN risk factors were present in 1216 (45.7%) patients, with age ≥65 years being the most common risk factor at 761/2663 (28.6%). It should be noted that in patients younger than 65 years, the RDI was 91.5%, and in elderly patients (≥65 years) 88.7%. Dose-limiting neutropenia was reported in 19 (0.7%) patients. There were 74 cases of grade 3–4 AEs (according to CTCAE v.5) in 59 (1.8%) patients. The most common were neutropenia, anemia, and diarrhea in 19 (0.7%), 7 (0.2%), and 6 (0.2%) patients, respectively. Serious AEs were reported in 17 patients (0.5%). Conclusion. Primary prophylaxis of FN with long-acting granulocyte colony-stimulating factor empegfilgrastim effectively maintains RDI in various nosological and therapeutic groups of patients with different CT regimens in real-world clinical practice.