Immunogenicity assessment of lipegfilgrastim in patients with breast cancer receiving chemotherapy

Lipegfilgrastim is a long-acting,once-per-cycle,glycopegylated recombinant granulocyte colony-stimulating factor (g-csf) used to prevent neutropenia in patients receiving myelosuppressive chemotherapy. this integrated analysis examined the immunogenicity of lipegfilgrastim and its potential clinical impact in two double-blind randomized studies (phases ii and iii) of patients with breast cancer receiving chemotherapy. serum samples were analyzed using sequential assays for screening,confirmation,antibody titer,and characterization of antidrug antibodies (ada). neutropenia-related efficacy measures were reviewed for each ada-positive patient. among 255 patients receiving lipegfilgrastim (154 in phase ii,101 in phase iii) and 155 patients receiving pegfilgrastim (54 in phase ii,101 in phase iii),the incidence of treatment-emergent ada was low and similar between the lipegfilgrastim (phase ii: 1.3%; phase iii: 1.0%) and pegfilgrastim (phase ii: 1.9%; phase iii: 1.0%) arms. none of the treatment-emergent ada-positive samples exhibited neutralizing activity against lipegfilgrastim,pegfilgrastim,or glycosylated g-csf in a cell-based neutralizing antibody assay. no changes were observed in neutropenia-related efficacy measures among ada-positive patients,and no treatment-related hypersensitivity or anaphylaxis occurred. these results indicate that there is no apparent impact of ada on lipegfilgrastim efficacy and safety. © 2016 linglong zou et al.