Eribulin mesylate safe, effective in hormone-refractory, triple-negative breast cancers

Eribulin mesylate (EM) shows promise as a third-line chemotherapy option for patients with hormone-resistant or triple-negative breast cancer, reports a study.

“This multicenter study, albeit retrospective, demonstrates the activity of this combination as third-line chemotherapy option in a challenging clinical setting such as triple-negative or hormone-resistant patients with breast cancer progressing after several lines of hormonal manipulations,” the authors said.

The study was conducted in four inter-related oncology centres. EM was delivered at a dose of 1.4 mg/m² in 100 mL of normal saline over 2 to 5 minutes on days 1 and 8 every 21 days. This was continued until disease progression or unacceptable toxicity.

The authors reported side effects every cycle as per standard clinical practice and graded these according to NCI-CTCAE, version 4.0. They also reported time to progression and overall survival.

Ninety patients were included in the analysis, with an overall response rate of 22 percent. The rates for the hormonal-resistant and triple-negative groups were 21 percent and 23 percent, respectively. Stable disease was recorded in 24 percent of patients in the whole series, 21 percent in the hormonal-resistant group, and 27 percent in the triple-negative group.

Time to progression was 3.5 months (range, 1–22) in the whole series, 3.0 months (range, 1–14.7) in the hormonal-resistant group, and 3.4 months (range, 2.2–16.2) in the triple-negative group. Overall survival extended to a median of 11.4 months.

“EM is a fully synthetic macrocyclic ketone analogue of the marine natural product halichondrin,” the authors said. “[It] has been reported to be active in metastatic breast cancer.”