Abstract OT3-02-03: An observational study of dose dense chemotherapy with lipegfilgrastim support in early breast cancer

Abstract

Abstract Background: The combination of the anthracycline, doxorubicin with cyclophosphamide (AC) is a widely used chemotherapy regimen in early stage breast cancer. Studies have shown that dose dense chemotherapy (incorporating AC) improved both disease-free survival and overall survival compared to once every 3 week treatment with daily subcutaneous G-CSF support. An important advance in the use of dose dense chemotherapy regimens was the development of pegylated forms of G-CSF, which offered the convenience of a single subcutaneous injection, rather than multiple daily injections. Lipegfilgrastim is a pegylated long-acting covalent conjugate of filgrastim (G-CSF). In a pivotal randomised phase III study in breast cancer lipegfilgrastim was shown to be non-inferior to pegfilgrastim. Although lipegfilgrastim is licensed in Europe and can facilitate every 2 week (dose dense) scheduling of chemotherapy there are a lack of prospective data about its efficacy in this setting. In this prospective, non-interventional, study we are investigating the incidence of treatment-related neutropaenia following four cycles of dose dense AC with lipegfilgrastim support. Methods: The primary end point of this prospective, single arm study is to determine the incidence of treatment-related neutropaenia, defined as an absolute neutrophil count (ANC) of <1.0 x 109/L, following four cycles of dose dense AC with lipegfilgrastim support. The secondary end points are to (1) determine the incidence of febrile neutropaenia, defined as temperature > 38°C and ANC <1.0 x 109/L, during 4 cycles of dose dense AC with lipegfilgrastim and (2) examine the incidence of treatment-related neutropaenia during subsequent intravenous chemotherapy post completion of AC. Eligibility criteria include, patients with stage I-III breast cancer, planned treatment with dose dense AC in the adjuvant or neoadjuvant setting, age ≥ 18 years, Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1 and adequate bone marrow function. Patients with prior exposure to chemotherapy and/or G-CSF, who are pregnant, have a cardiac or other concurrent illness, which at the investigator's discretion contraindicates the use of AC will be excluded. We will enrol 40 consecutive patients who are planned to undergo dose dense AC. Based on previous clinical trials, we expect that the incidence of treatment-related neutropaenia will be <12%. However, it is likely that the current study will more closely resemble real-world practice and a higher incidence of treatment-related neutropaenia may be observed. This study has been approved by the Instituational Review Board and 9 patients have been consented to date. (registered with clinicaltrials.gov). Citation Format: Lyons T, Mallet V, Collins D, Malone E, Milewski M, Egan K, Hennessy B, Grogan L, Breathnach O, Morris P. An observational study of dose dense chemotherapy with lipegfilgrastim support in early breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-03.