FDA approves Afinitor for advanced breast cancer
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. Another option is now available for women suffering from advanced breast cancer. On July 20, the US Food and Drug Administration (FDA) approved Afinitor (everolimus) for use in combination with Aromasin (exemestane) to treat certain postmenopausal women with advanced hormone-receptor positive, HER2-negative breast cancer. The drug combination is intended for use in women with recurrence or progression of their cancer after treatment with Femara (letrozole) or Arimidex (anastrozole). Afinitor is marketed by Novartis Pharmaceuticals Corporation (East Hanover, NJ).
“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,” noted Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. He added, “Afinitor is another example of the value of continuing to study drugs in additional types of cancer after their initial approval.”
A clinical study comprised of 724 patients with advanced breast cancer was conducted to evaluate the safety and effectiveness of Afinitor was evaluated. All patients were postmenpausal, had estrogen receptor-positive, HER2-negative breast cancer that had metastasized, and had previously received treatment with Femara or Arimidex. The patients were randomized to receive either Afinitor in combination with Aromasin or Aromasin with a placebo. The 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). The researchers found that, compared to the patients receiving the placebo, those who were assigned to receive Afinitor plus Aromasin combination had a 4.6 month improvement in the median time to disease progression or death.
The most common side effects observed in patients receiving Afinitorwere mouth ulcers, infections, rash, fatigue, diarrhea, and decreased appetite. The researchers cautioned that 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 received FDA approval for other types of cancers: patients with advanced renal cell carcinoma that has progressed after treatment with other cancer therapies; adult patients with progressive advanced neuroendocrine tumors of pancreatic origin; 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.