Comparison of pegfilgrastim on day 2 vs. day 4 as primary prophylaxis of intense dose-dense chemotherapy in patients with node-positive primary breast cancer within the prospective, multi-center GAIN study: (GBG 33)

Background Preliminary data suggest that pegfilgrastim given on day 4 (P4) might be superior to pegfilgrastim on day 2 (P2) in reducing grade 4 leucopenia. Methods Patients with node-positive primary breast cancer receiving epirubicin–paclitaxel–cyclophosphamide chemotherapy were randomized to receive P2 versus P4. Primary endpoint was leucopenia grade 4, assuming a risk reduction of 50% with P4 from 50% in P2 to 25% with P4. Results Three-hundred fifty-one patients were randomized to P2 ( n = 174) versus P4 ( n = 177). The rate of leucopenia (grade 4) was 47.1% with P2 and 42.0% with P4 ( p = 0.387), neutropenia (grade 3 + 4) was 47.9% versus 40.8% ( p = 0.337), FN was 4.7% versus 8.0% ( p = 0.271), and infections was 29.9% versus 25.4% ( p = 0.404), respectively. Conclusion This study failed to demonstrate that pegfilgrastim on day 4 was more efficacious than on day 2 with respect to grade 4 leucopenia (the primary endpoint), febrile neutropenia, or infections.