Results of a phase III, randomized, double-blind, placebo-controlled trial of pegfilgrastim (PEG) in patients (pts) receiving first-line FOLFOX or FOLFIRI and bevacizumab (B) for colorectal cancer (CRC).

LBA445 Background: The literature reports that adding biologics to chemotherapy (ctx) may increase the incidence of clinically significant neutropenia. This trial was conducted to evaluate the efficacy of PEG in reducing the incidence of febrile neutropenia (FN) in pts with locally advanced (LA) or metastatic (m)CRC receiving first-line treatment with either FOLFOX/B or FOLFIRI/B. Methods: Key eligibility: ≥ 18 years old; measurable, nonresectable CRC per RECIST 1.1. Pts were randomly assigned 1:1 to either placebo or 6 mg PEG ~24 h after ctx/B. The study treatment period included four Q2W cycles, but pts could continue their assigned regimen until progression. Pts were stratified by region (North America vs rest of world), stage (LA vs mCRC), and ctx (FOLFOX vs FOLFIRI). Estimated sample size (N = 800) was based on the expected incidence of grade 3/4 FN (primary endpoint) across the first 4 cycles of ctx/B, powered for PEG superiority over placebo. Other endpoints included overall response rate (ORR), pr...