1030P - Real-world comparative effectiveness analysis of second-line (2L) nab-paclitaxel (nab-P) vs eribulin (Erib) in patients (Pts) with metastatic breast cancer (MBC)

Abstract

nab-P and Erib are approved for ≥ 2L treatment (Tx) of MBC. However, no data are available on comparative effectiveness of nab-P vs Erib for 2L Tx of MBC in the real-world setting. Fully de-identified data from a US electronic medical record platform of 1300 community (not university-based) oncologists were used in this retrospective study of women aged ≥ 18 yrs with MBC who started nab-P or Erib monotherapy as 2L Tx from 12/1/10 to 4/6/15 (≥ 1 cycle of nab-P or Erib required to be included). Time to Tx discontinuation (TTD, day 1 to last date + 7 days for 7-day cycle and day 1 to last date + 21 days for 21-day cycle) and time to next Tx (TTNT; day 1 of line 2 to day 1 of line 3) were the primary objectives. Adverse events (AEs) and supportive care were also examined. Subset analyses examined outcomes in pts with hormone receptor–positive (HR+)/human epidermal growth factor receptor 2–negative (HER2-) or triple-negative (TN) MBC. This analysis included 176 pts (107 treated with nab-P and 69 with Erib). Baseline characteristics were similar between groups except that more pts treated with 2L nab-P had HR+ disease (P = 0.02) and were on combination Tx with a targeted agent (P = 0.03). More pts in the Erib group had used a taxane prior to MBC diagnosis (P = 0.01 for ≤ 1 year). Few pts with TN MBC were treated with 2L nab-P or Erib (Table). Overall, nab-P was associated with numerically longer TTD and TTNT vs Erib. AE rates were similar except that thrombocytopenia occurred more often with Erib. Antiemetics (IV) and G-CSF were used less often with nab-P. Steroids were used less often with Erib. Similar trends were reported in pts with HR + /HER2- or TN MBC.Tabled 1nab-P n = 107Eribulin n = 69Unadjusted P ValueAdjusted P ValueOverall populationAge, mean, years60610.688-Schedule, weekly, %75---TTD, median, mos4.03.10.0740.507TTNT, median, mos6.04.70.5380.759Any grade AE in > 5% pts, %Anemia28.042.00.0550.130Neutropenia18.723.20.4700.376Thrombocytopenia7.518.80.0230.107Nausea + vomiting11.25.80.2220.299Dehydration8.42.90.205-Fatigue2.87.20.266-Pain2.87.20.266-Supportive Care doses/pt/100 daysAntimetic (IV Only)5.776.92<0.0010.004Steroids6.215.470.0310.018Tx for hydration3.733.700.9230.522Tx for bone loss1.902.050.4520.020G-CSF1.443.19<0.001<0.001HR + /HER2-nMedian, mosnMedian, mosTTD674.2272.90.351-TTNT396.9144.40.222-Triple negativenMedian, mosnMedian, mosTTD203.3232.60.124-TTNT136.0114.70.794- Open table in a new tab In this US-based, real-world analysis, TTD and TTNT were numerically longer with nab-P compared with Erib, including in the HR + /HER2- and TN subsets. AEs were similar between the 2 groups. Pts receiving nab-P required less supportive care.