Another Option Added for Treating Late-Stage Breast Cancer
The FDA has approved eribulin mesylate (Halaven) for the treatment of metastatic breast cancer in women who have received at least two prior chemotherapy regimens for late-stage disease.
Eribulin is a synthetic form of a compound derived from the sea sponge Halichondria okadai; the drug is believed to suppress the growth of cancer cells by inhibiting microtubule formation. Before receiving eribulin, an injectable therapy, patients should have received prior anthracycline- and taxane-based chemotherapy for early- or late-stage breast cancer.
The FDA’s approval was based on the phase III EMBRACE study. Preliminary results presented at the American Society of Clinical Oncology annual meeting in June showed a 2.5 month improvement in median overall survival among patients who received eribulin compared with the control group. The median overall survival for patients who received eribulin was 13.1 months, compared with 10.6 months for those who received other single-agent therapy.
The study included 762 women who had metastatic breast cancer and had received at least two prior chemotherapy regimens. The patients were randomly assigned to receive either eribulin or a different single-agent therapy chosen by their oncologist.
Common side effects included a decrease in infection-fighting white blood cells (neutropenia), anemia, a decrease in the number of white blood cells (leukopenia), hair loss (alopecia), fatigue, nausea, weakness (asthenia), nerve damage (peripheral neuropathy), and constipation.
“There are limited treatment options for women with aggressive forms of late-stage breast cancer who have already received other therapies,” said Dr. Richard Pazdur, director of the Office of Oncology Drug Products in the FDA’s Center for Drug Evaluation and Research, in a statement. “Halaven shows a clear survival benefit and is an important new option for women.”
Denosumab Approved to Prevent Bone Problems in Cancer Patients
Denosumab, a monoclonal antibody approved in June 2010 to treat osteoporosis in postmenopausal women at high risk for bone fractures, received supplemental approval at a higher dose to prevent skeletal problems in patients with bone metastases from solid tumors. In clinical trials, denosumab was superior to zoledronic acid (Zometa) at prolonging the time before patients with a variety of cancers had a fracture or spinal cord compression or required surgery or radiotherapy for bone pain.
When administered to patients with cancer, denosumab has a different safety profile than when given for osteoporosis and is known by a different trade name (Xgeva, instead of Prolia). Denosumab is also given more frequently and at a higher dose to patients with cancer, who receive injections of 120 mg every 4 weeks, than to patients with osteoporosis, who receive 60 mg every 6 months.
“Xgeva has a different mechanism of action than currently approved drugs aimed at reducing bone complications from cancer,” said the FDA’s Dr. Richard Pazdur. In three large international clinical trials that enrolled a total of 5,723 patients, denosumab was superior to zoledronic acid in women with breast cancer and men with prostate cancer. The drugs had a similar effect in patients with other cancers, including non-small cell lung cancer, multiple myeloma, kidney cancer, and small cell lung cancer. However, denosumab is not approved for patients with multiple myeloma or other cancers of the blood.