Abstract
Background: Both PEG-rhG-CSF and rhG-CSF are widely used in autologous hematopoietic stem cell mobilization for lymphoma. There is still a lack of prospective studies comparing the two mobilizing agents in autologous stem cell mobilization for lymphoma.
Aims: To evaluate the efficacy and safety of PEG-rhG-CSF in autologous stem cell mobilization for lymphoma patients.
Methods: In this single-arm, multicenter, bidirectional cohort clinical study (NCT04460508), 140 patients were planned to be enrolled. This is the result of the interim analysis, and all the patient data are from the Department of Hematology, the First Hospital of Jilin University. All patients underwent chemotherapy combined with mobilization. The chemotherapy regimen was selected according to the patients' previous chemotherapy regimens and the researchers' experience. In the experimental group, 48 - 72 hours after the end of chemotherapy, a fixed dose of 9mg of PEG-rhG-CSF was subcutaneously injected. In the control group, when the platelets and white blood cells began to rise after reaching the lowest point after chemotherapy, rhG-CSF (Filgrastim) at a dose of 10 μg/kg/d was given. In both groups, routine blood tests and peripheral blood CD34+ cell counts were monitored daily. Collection was started when WBC≥2.0×109 /L and CD34+ cells≥20/ul. The collection endpoint was to collect ≥2×106 /kg CD34+ cells. If the collection failed to reach the endpoint after more than 3 times, it was regarded as a collection failure. The primary endpoint was the mobilization success rate. The secondary endpoints were the lowest and peak values of white blood cells, the time to the highest point of D34+ cells (the number of days from the first day of chemotherapy to the peak of CD34+ count), the single collection volume, the number of collection. In this study, patients with bone marrow involvement and massive splenomegaly were excluded, and the use of plerixafor for rescue was not allowed.
Results: 1. From January 1, 2021, to May 16, 2024, 76 eligible patients were enrolled. Six patients withdrew from the study due to personal reasons. A total of 70 patients were included in this analysis, with 26 in the experimental group (PEG-rhG-CSF) and 44 in the control group (rhG-CSF). 2. There were no significant differences in baseline comparisons between the two groups in terms of age, gender, body weight, liver and kidney function, white blood cells, hemoglobin, platelets, and absolute neutrophil count. 2. The primary study endpoint was the mobilization success rate. In the experimental group, it was 90.5% (19/21), and in the control group, it was 88.4% (38/44), with P > 0.999. 3. The secondary study endpoints, the nadir and peak values of white blood cells: in the experimental group, the median was 0.8 (0.1 - 3.3)×109 /L and 18.2 (10.6 - 45.8)×109 /L; in the control group, they were 0.6 (0.1 - 5.5)×109 /L and 23.9 (4.5 - 92.5)×109 /L, with P = 0.981 and P = 0.334. The number of days to reach the peak of CD34+ count: the median in the experimental group was 9.0 (5 - 17) days, and in the control group, it was 14 (4 - 42) days, P < 0.001. The optimal single collection volume: the median in the experimental group was 4.3 (0.6 - 31.5)×106 /kg, and in the control group, it was 3.8 (0.6 - 20.4)×106 /kg, with P = 0.699. The number of collections: the median in the experimental group was 1 time (52.4% had successful single collection, 28.6% had successful collection in 2 times, and 19% had collection in 3 times), and in the control group needed 2 collections (46.5% had successful single collection, 53.5% had successful collection in 2 times, and 0% had collection in 3 times), P = 0.006. 4. Among the grade ≥ 3 adverse reactions, the highest incidence was thrombocytopenia, with 65.4% in the experimental group and 27.3% in the control group, P = 0.002; followed by decreased lymphocyte count (73.1%, 70.5%, P = 0.814) and anemia (26.9%, 13.6%, P = 0.288).
Conclusions: For lymphoma patients undergoing chemotherapy combined with PEG-rhG-CSF for mobilizing peripheral blood stem cells, compared with the combination of rhG-CSF, the mobilization success rate is the same, while the peak of CD34+ is reached earlier, and the number of collections to reach the standard is significantly reduced, with 52.4% of patients only needing 1 collection. Among the adverse reactions, the degree and proportion of thrombocytopenia during the PEG-rhG-CSF process are more severe, which requires clinical attention.
