The FDA has approved Afinitor (everolimus) for use in combination with Aromasin (exmestane) for the treatment of certain postmenopausal women with advanced hormone-receptor positive, HER2-negative breast cancer.
This drug combination is intended for use in women with recurrence or progression of their cancer after treatment with Femara (letrozole) or Arimidex (anastrazole).
Breast cancer is the second leading cause of cancer-related death among women. This year an estimated 226,870 women will be diagnosed with breast cancer, and 39,510 will die from the disease.
Afinitor 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. The safety and effectiveness of the drug was evaluated in a clinical study of 724 patients with advanced breast cancer. All patients had experienced menopause, had estrogen receptor-positive, HER2-negative breast cancer that had spread, and had previously received treatment with Femara or Arimidex. Patients were selected to receive either Afinitor in combination with Aromasin, or Aromasin with a placebo (sugar pill). Patients received treatment until their cancers progressed or side effects became unacceptable.
The study was designed to measure the length of time a patient lived without the cancer progressing, or progression-free survival (PFS). Patients who were assigned to receive the Afinitor plus Aromasin combination had a 4.6 month improvement in the median time to disease progression or death compared to patients receiving the placebo plus Aromasin.
The most common side effects observed in patients receiving Afinitor for breast cancer were mouth ulcers, infections, rash, fatigue, diarrhea and decreased appetite. Patients aged 65 years and older should be monitored closely as these patients experience a higher rate of serious side effects than younger patients receiving the treatment.
Afinitor has previously been approved by the FDA to treat patients with advanced renal cell carcinoma that has progressed after treatment with other cancer therapies, in adult patients with progressive 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 East Hanover, N.J.-based Novartis Pharmaceuticals Corporation.