Abstract P3-12-07: A multicenter randomized double-blind phase III clinical trial to evaluate the efficacy and safety of GCPGC, a novel pegylated G-CSF in patients receiving DA or TAC chemotherapy for breast cancer compared to peg-filgrastim

Introduction Treatment with cytotoxic chemotherapy is known to be associated with a significant risk of febrile neutropenia. GCPGC(Green Cross Co., Korea) is a novel long acting recombinant human granulocyte colony-stimulating factor (G-CSF) analog that reduces the severity and duration of neutropenia. We conducted a phase III trial to evaluate the efficacy and safety of GCPGC compared to pegfilgrastim. Methods A total of 117 patients were enrolled in this multicenter, phase III, double-blind randomized trial between Feb 2012 and May 2013. They were randomly assigned to receive either GCPGC or pegfilgrastim during the maximal 6 cycles of chemotherapy which consisted of DA (docetaxel and doxorubicin) or TAC (docetaxel, doxorubicin, and cyclophosphamide). Based on the results of the phase II dose-finding study for GCPGC, the dose of 6 mg was selected. Both medications were administered 24 hours after the completion of each cycle of chemotherapy. The primary efficacy endpoint of this study was the duration of grade 4 neutropenia (Absolute Neutrophil Count (ANC) 3 ) during the first cycle of chemotherapy. Secondary endpoints included the time to ANC recovery during the first cycle of chemotherapy, which was defined as the number of days required for neutrophil counts to exceed 2,000/mm 3 , the rate of febrile neutropenia, the rate of severe neutropenia which persisted for more than three days during first cycle of chemotherapy, the depth of ANC nadir, the ANC level on day 7 after each cycle of chemotherapy, the frequency of dose reduction or delay, the number of hospitalization related to febrile neutropenia after the first cycle of chemotherapy, and the number of treatment with intravenous antibiotics. Results A total of 116 patients were evaluable for safety and 115 patients were evaluable for efficacy. The intention-to-treat analysis showed that there was no statistical difference between GCPGC and pegfilgrastim in terms of the duration (days) of grade 4 neutropenia in chemotherapy cycle 1 (1.64±1.18 vs 1.80±1.05; difference -0.15±1.11 [97.5% C.I. -, 0.26]; the pre-specified non-inferiority margin of 1.0). Notably, patients treated with GCPGC had a statistically significant reduction in the time to recovery from neutropenia (ANC >2,000/mm 3 ), one of the secondary endpoints of the study, compared to those treated with pegfilgrastim (8.85 ± 1.45 vs. 9.83 ± 1.20 days; p Conclusion Collectively, GCPGC is not inferior to peg-filgrastim and represents an effective alternative for reducing the duration of neutropenia in breast cancer patients receiving TAC or DA chemotherapy. Citation Format: Joo Han Lim, Ki-Hyeong Lee, Keon-Uk Park, In-Hae Park, Eun Kyung Cho, Moon Hee Lee, So-Young Yoon, Jee-Hyun Kim, In-Sil Choi, Jae-Hoo Park, Young-Jin Choi, Hee-Jun Kim, Kyung Hae Jung, Si-Young Kim, Do-Youn Oh, Seock-Ah Im. A multicenter randomized double-blind phase III clinical trial to evaluate the efficacy and safety of GCPGC, a novel pegylated G-CSF in patients receiving DA or TAC chemotherapy for breast cancer compared to peg-filgrastim [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-12-07.