Lipegfilgrastim is a novel glyco-pegylated granulocyte-colony stimulating factor in development for neutropenia prophylaxis in cancer patients receiving chemotherapy. This phase III, double-blind, randomized, active-controlled, noninferiority trial compared the efficacy and safety of lipegfilgrastim versus pegfilgrastim in chemotherapy-naive breast cancer patients receiving doxorubicin/docetaxel chemotherapy.

Patients with high-risk stage II, III, or IV breast cancer and an absolute neutrophil count >=1.5x109 cells/L were randomized to a single 6-mg subcutaneous injection of lipegfilgrastim (n = 101) or pegfilgrastim (n = 101) on day 2 of each 21-day chemotherapy cycle (4 cycles maximum). The primary efficacy endpoint was the duration of severe neutropenia during cycle 1.

Cycle 1: The mean duration of severe neutropenia for the lipegfilgrastim and pegfilgrastim groups was 0.7 and 0.8 days, respectively (lamda=-0.218, [95% confidence interval: --0.498%, 0.062%], p = 0.126), and no severe neutropenia was observed in 56% and 49%. All cycles.

In the efficacy population, febrile neutropenia occurred in three (all in cycle 1) and zero patients, respectively. Treatment-related adverse events in the safety population were reported in 28% and 26% of patients, respectively.

This study demonstrates that lipegfilgrastim 6 mg is as effective as pegfilgrastim in reducing neutropenia in patients with breast cancer receiving myelosuppressive chemotherapy.

Trial Registration

Eudra EEACTA200901599910. https://www.clinicaltrialsregister.eu/ctr-search/search?query=XM22-03

The study protocol, two global amendments (Nos. 1 and 2), informed consent documents, and other appropriate study-related documents were reviewed and approved by the Ministry of Health of Ukraine Central Ethics Committee and local independent ethics committees (IECs).