Eribulin monotherapy in patients aged 70 years and older with metastatic breast cancer

Following the demonstrated efficacy and safety of eribulin mesylate in heavily pretreated patients with metastatic breast cancer, an exploratory analysis was performed to investigate the effect of age in these patients.

Data were pooled from two single-arm phase II studies and one open-label randomized phase III study in which patients received eribulin mesylate at 1.4 mg/m(2) as 2- to 5-minute intravenous infusions on days 1 and 8 of a 21-day cycle. The effect of age on median overall survival (OS), progression-free survival (PFS), overall response rate (ORR), clinical benefit rate (CBR), and incidence of adverse events (AEs) was calculated for four age groups (<50 years, 50-59 years, 60-69 years, ≥ 70 years). RESULTS. Overall, 827 patients were included in the analysis (<50 years, n = 253; 50-59 years, n = 289; 60-69 years, n = 206; ≥ 70 years, n = 79). Age had no significant impact on OS (11.8 months, 12.3 months, 11.7 months, and 12.5 months, respectively; p = .82), PFS (3.5 months, 2.9 months, 3.8 months, and 4.0 months, respectively; p = .42), ORR (12.7%, 12.5%, 6.3%, and 10.1%, respectively), or CBR (20.2%, 20.8%, 20.4%, and 21.5%, respectively). Although some AEs had higher incidence in either the youngest or the oldest subgroup, there was no overall effect of age on the incidence of AEs (including neuropathy, neutropenia, and leukopenia).

Eribulin monotherapy in these selected older patients with good baseline performance status led to OS, PFS, ORR, CBR, and tolerability similar to those of younger patients with metastatic breast cancer. The benefits and risks of eribulin appear to be similar across age groups.