Phase 3 noninferiority trial of efbemalenograstim alfa versus pegfilgrastim for chemotherapy-induced neutropenia in breast cancer patients

A phase 3 noninferiority (NI) trial evaluated the efficacy and safety of efbemalenograstim alfa (E-alfa), a novel non-pegylated, long-acting, G-CSF, for the management of chemotherapy-induced neutropenia (CIN) in patients with breast cancer undergoing docetaxel and cyclophosphamide chemotherapy. Patients were randomized 1:1 to E-alfa or pegfilgrastim. Primary endpoint was duration of severe neutropenia (DSN) in cycle 1. Mean DSN was 0.2 ± 0.51 days with E-alfa versus 0.2 ± 0.45 days with pegfilgrastim, confirming NI. A secondary endpoint was incidence of severe neutropenia (ISN). ISN was lower with E-alfa compared with pegfilgrastim in cycle 4. The safety profile of E-alfa was comparable with that of pegfilgrastim. The authors conclude that E-alfa was noninferior to current CIN therapy with comparable efficacy and safety profiles in cycle 1 with evidence of less neutropenia in later cycles.