A randomized multicenter phase II trial of mecapegfilgrastim single administration versus granulocyte colony-stimulating growth factor on treating chemotherapy-induced neutropenia in breast cancer patients

Backgrounds: This study aimed to evaluate the efficacy and safety of mecapegfilgrastim (HHPG-19K) with different doses compared to granulocyte colony-stimulating growth factor (G-CSF) in treating chemotherapy-induced neutropenia in breast cancer patients. Methods: A total of 182 breast cancer patients were enrolled in this multi-center, randomized, phase II trial and developed neutropenia after first cycle chemotherapy. Patients were then assigned as 1:1:1 ratio to receive 100 μg/kg HHPG-19K single injection (HHPG-19K-N group), 150 μg/kg HHPG-19Ksingle injection (HHPG-19K-H group) and 5 μg/kg G-CSF daily injection (G-CSF group) at day 3 of the second cycle (cycle 2) chemotherapy. The primary endpoint was incidence of grade ≥3 neutropenia during cycle 2. Study drug-related adverse events during cycle 2 were recorded for safety assessment. Results: During cycle 2 chemotherapy, both HHPG-19K-N and HHPG-19K-H groups exhibited lower incidence of grade ≥3 neutropenia compared with G-CSF group, while no difference was observed between HHPG-19K-N and HHPG-19K-H groups. Also, better outcomes were observed in HHPG-19K-N and HHPG-19K-H groups compared with G-CSF group regarding to grade 4 neutropenia, duration of grade ≥3 neutropenia, duration of grade 4 neutropenia, incidence of febrile neutropenia (FN) and rescue application of G-CSF, time to ANC recovery, while no difference of these outcomes between HHPG-19K-N and HHPG-19K-H groups was observed. For safety analysis, the incidences of hematologic and non-hematologic adverse events were similar among the 3 groups. Conclusions: HHPG-19K presents with better clinical efficacy as well as equal tolerance compared with G-CSF in treating chemotherapy-induced neutropenia in breast cancer patients.