Breast cancer is the second major female cancer killer in the USA. 226,870 patients are expected to be diagnosed with the disease this year, and 39,510 will die from breast cancer.
Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products, the Center for Drug Evaluation and Research, FDA, said:
"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. Afinitor is another example of the value of continuing to study drugs in additional types of cancer after their initial approval."
When considering Afinitor for approval, the FDA evaluated its safety and efficacy in a study involving 724 participants with advanced breast cancer. They had all gone through the menopause and had estrogen receptor-positive, HER2-negative breast cancer that had metastasized. They had all received Femara or Arimidex therapy. They were randomly selected to receive either Afinitor together with Aromasin, or Aromasin plus a placebo (dummy drug). Treatment continued until either cancer progressed or side effects were too great.
The study's primary outcome was how long patients lived without cancer progression, or PFS (progression-free survival). The study showed that those on the Afinitor plus Aromasin combination experienced a 4.6-month improvement in the average time to disease progression or death compared to the Aromasin plus placebo group.
Side effects related to Afinitor included loss of appetite, diarrhea, fatigue, rash, infections and mouth ulcers.
The FDA emphasized that women aged 65 years or more should be closely monitored, because they tend to have more serious side effects compared to their younger counterparts.
Afinitor was already approved for the treatment of advanced renal cell carcinoma that progressed after other cancer therapies were administered, as well as for progressive advanced neuroendocrine tumors of pancreatic origin, renal angiomyolipoma and tuberous sclerosis complex (TSC) not requiring immediate surgery, and for children and adults with subependymal giant cell astrocytoma associated with TSC who are not going to undergo curative surgery.
Afinitor is made and distributed by Novartis Pharmaceuticals Corporation.
According to Novartis, approximately 220,000 women worldwide are diagnosed annually with advanced HR+breast cancer, the most common form of breast cancer. In the USA, almost 40,000 patients will probably be diagnosed with advanced breast cancer in 2012. At the time of diagnosis, about 70% of all invasive breast cancer are positive for HR expression.
Hervé Hoppenot, President, Novartis Oncology, said:
"The approval of Afinitor in advanced breast cancer marks a very proud day for the breast cancer community and Novartis. We are bringing a highly-effective treatment to women and their physicians who are in need of new approaches in the battle against this disease. This milestone is a result of an extensive collaboration with researchers around the world who have helped study Afinitor in advanced breast cancer, as well as the more than 700 women who participated in the trial."
Novartis informs that Afinitor now has five indications. This latest FDA approval is the first for an mTOR inhibitor for treating HR+ breast cancer in America. Two studies are ongoing for Afinitor therapy for HER2-positive breast cancer. Last month, the CHMP (Committee for Medicinal Products for Human Use) of the EMA (European Medicines Agency) issued a "positive opinion" for Afinitor for the treatment of HR+/HER2-negative breast cancers.