Randomized Trial of Fixed-Dose Capecitabine Compared With Standard-Dose Capecitabine in Metastatic Breast Cancer: X-7/7 Trial.

Journal: JCO Oncology Advances
Published:
Abstract

Objective: In metastatic breast cancer (MBC), oral capecitabine prescribed at the US Food and Drug Administration (FDA)-approved dose of 1,250 mg/m2 twice daily, 14 days on, 7 days off, is associated with poor tolerance. Mathematical models suggest that a fixed-dose (FD), dose-dense schedule may optimize efficacy. We conducted a randomized, open-label trial to compare the efficacy and tolerability of FD capecitabine, 1,500 mg twice daily, 7 days on, 7 days off (FD-7/7), with the FDA-approved dose and schedule (standard-dose [SD]-14/7).

Methods: Females with MBC and any previous lines of therapy were included. Patients were randomly assigned 1:1 to either FD-7/7 or SD-14/7. The primary end point was 3-month progression-free survival (PFS). Capecitabine-related toxicities were graded at each visit.

Results: Between October 2015 and April 2021, 153 patients were enrolled (n = 80 FD-7/7, n = 73 SD-14/7). The 3-month PFS was 63.1% (95% CI, 52.0 to 74.2) in the FD-7/7 arm and 67.2% (95% CI, 54.5 to 79.9) in the SD-14/7 arm. Restricted mean survival time was used to report estimates of effect. The PFS (restricted mean) at 33 months was 10.1 months (95% CI, 7.6 to 12.6) in the FD-7/7 arm compared with 9.1 months (95% CI, 6.6 to 11.7) in the SD-14/7 arm. The overall survival (restricted mean) at 80 months was 30.6 months (95% CI, 23.6 to 37.6) in the FD-7/7 arm versus 24.5 months (95% CI, 18 to 31.1) in the SD-14/7 arm. Toxicity-related treatment discontinuation occurred in 24 patients (32.9%) in the SD-14/7 arm compared with seven patients (8.8%) in the FD-7/7 arm (P = .0002). Grade 2 to 4 toxicities occurred in 79.5% in the SD-14/7 arm compared with 37.5% in the FD-7/7 arm (P < .0001).

Conclusions: In MBC, FD capecitabine 1,500 mg twice daily on a 7/7 schedule has less toxicity and similar efficacy when compared with body surface area-based dosing on a 14/7 schedule.

Authors
Qamar Khan, Colleen Bohnenkamp, Taylor Monson, Milind Phadnis, Lauren Clark, Holly Smith, Vinay Raja, Manana Elia, Anne O'dea, Mark Fesen, Gregory Crane, Lauren Nye, Joaquina Baranda, Robert Pluenneke, Marc Hoffmann, Raed Moh'd Al Rajabi, Anup Kasi, Richard Mckittrick, Laura Mitchell, Stephanie Lafaver, Priyanka Sharma
Relevant Conditions

Breast Cancer