The FDA has approved Afinitor (everolimus) for use in combination with exemestane (Aromasin) to treat postmenopausal women with advanced hormone-receptor positive, HER2-negative breast cancer.
The drug combination, the FDA notes, is intended for use in women with recurrence or progression of their cancer after treatment with letrozole (Femara) or anastrozole (Arimidex).
”This is the first approval from the class of drugs known as mTOR inhibitors for the treatment of postmenopausal women with advanced hormone-receptor positive breast cancer,” Richard Pazdur, MD, Director of the FDA's Office of Hematology and Oncology Products in the Center for Drug Evaluation and Research, said in an FDA news release. “Afinitor is another example of the value of continuing to study drugs in additional types of cancer after their initial approval.”
Also commenting, in a news release from Afinitor's manufacturer, Novartis Pharmaceuticals, Gabriel Hortobagyi, MD, Chair of Breast Medical Oncology at the University of Texas MD Anderson Cancer Center, said, “Afinitor is the first and only treatment that boosts the effectiveness of endocrine therapy, significantly extending the time women with advanced breast cancer live without tumor progression.
“This approval redefines the treatment and management of advanced hormone receptor-positive breast cancer, offering a critical new option for physicians and patients.”
Safety and effectiveness were evaluated in a study of 724 patients with advanced breast cancer. All patients had experienced menopause, had estrogen receptor-positive, HER2-negative metastatic breast cancer, and had previously received treatment with letrozole or anastrozole. Patients were selected to receive either everolimus in combination with Aromasin or Aromasin with a placebo. Patients received treatment until their cancers progressed or the side effects became unacceptable.
Patients who were assigned to receive the added Afinitor had a 4.6-month improvement in the median time to disease progression or death compared with patients receiving placebo plus Aromasin.
The most common side effects in patients receiving Afinitor for breast cancer were mouth ulcers, infections, rash, fatigue, diarrhea, and decreased appetite. The FDA cautions that patients age 65 and older should be monitored closely, since these patients experience a higher rate of serious side effects than younger patients receiving the treatment.
The FDA has previously approved Afinitor to treat patients with advanced renal cell carcinoma that has progressed after treatment with other cancer therapies, in adult patients with progressive advanced neuroendocrine tumors of pancreatic origin, for patients with renal angiomyolipoma and tuberous sclerosis complex (TSC) not requiring immediate surgery, and for adults and children with subependymal giant cell astrocytoma associated with TSC who require treatment but are not candidates for curative surgery.
Afinitor is marketed by Novartis Pharmaceuticals.