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

Background

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.

Methods

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.

Results

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.