E.U. approval has been granted to Novartis drug Afinitor® (everolimus) after successful completion of the Phase III BOLERO-2 (Breast cancer trials of OraL EveROlimus-2) trial.

Afinitor tablets have been approved for the treatment of hormone receptor-positive (HR+) and HER2/neu-negative (HER2-) advanced breast cancer (HR+ advanced breast cancer), in combination with exemestane in postmenopausal women without symptomatic visceral disease after recurrence or progression after a non-steroidal aromatase inhibitor.

Worldwide, around 220,000 women are diagnosed with HR+ advanced breast cancer and even though endocrine therapy will be the main treatment for these women, most will eventually develop resistance to therapy. This resistance has been linked to an over-activation of the PI3K/AKT/mTOR pathway, an important protein that regulates tumor cell division, blood vessel growth and cell metabolism. Afinitor is designed to target the mTOR pathway in cells.

Hervé Hoppenot, President of Novartis Oncology declared:

“The approval of Afinitor is an important milestone marking the first major advance for women in the European Union with hormone receptor-positive advanced breast cancer since the introduction of aromatase inhibitors more than 15 years ago. Treatment with Afinitor gives women a new option in the battle against this advanced form of breast cancer, where there remains a significant unmet need.”

The Phase III BOLERO-2 trial was a randomized, double blind, placebo-controlled, multi-center study, which involved 724 patients. A local investigator assessment revealed that Afinitor therapy together with exemestane more than doubled the average progression-free survival (PFS) rate to 7.8 months in comparison with 3.2 months with exemestane alone (hazard ratio=0.45 [95% Cl: 0.38 to 0.54]; p<0.0001). Another analysis based on an independent central radiology review also demonstrated that the average PFS was extended to 11.0 months with Afinitor treatment as compared with 4.1 months (hazard ratio=0.38 [95% CI: 0.31 to 0.48]; p<0.0001). The most frequently observed grade 3-4 adverse reactions with an incidence rate of 2% of more included infections, stomatitis, fatigue, hyperglycemia, dyspnea, pneumonitis and diarrhea.

Jose Baselga, MD, PhD, Chief of Hematology/Oncology at the Massachusetts General Hospital, who was co-leading researcher of the BOLERO-2 trial commented:

“By boosting the effectiveness of endocrine therapy, Afinitor significantly extends the time women with hormone receptor-positive advanced breast cancer live without tumor progression. Afinitor, the first mTOR inhibitor to be approved for this disease, has the potential to redefine the way this common form of advanced breast cancer is treated.”

Afinitor’s approval by the European Commission was made after the Committee for Medicinal Products for Human Use adopted a positive opinion of the drug on the 21 June 2012. Afinitor is now approved for the treatment of HR+ advanced breast cancer and applies to all 27 EU member states, including Iceland and Norway. In the U.S., Afinitor gained US FDA approval in combination with exemestane in the HR+/HER2- population after unsuccessful treatment with letrozole or anastrazole on 20 July 2012.

At present, other regulatory submissions for Afinitor in advanced breast cancer are under way in other countries around the world. Afinitor is also currently being investigated in HER2-positive breast cancer in two ongoing Phase III trials.

Advanced breast cancer is defined as metastatic breast cancer (stage IV), the most serious form of the disease that has spread to other parts of the body like to the liver and into the bones, and locally advanced breast cancer (stage III), i.e. when the cancer has spread to lymph nodes and/or other tissue local breast tissue, but which has not yet spread to distant sites in the body.

The average estimated life expectancy for women with metastatic cancer is around 18 to 36 months after diagnosis, whilst that of women with stage III cancer is less than five years. HR+ advanced breast cancer consists of hormone receptor-positive tumors, a group of cancers that express receptors for certain hormones, including estrogen and progesterone, and the growth of cancer cells can be driven by these hormones. One of the most significant predictors and prognostic markers of human breast cancer is the presence of estrogen receptors (ER) and/or progesterone receptors (PgR). Collectively these are referred to as hormone receptor-positive.

In the E.U., Afinitor (everolimus) is approved for the treatment of hormone receptor-positive (HR+), HER2/neu-negative (HER2-) advanced breast cancer in combination with exemestane in postmenopausal women without symptomatic visceral disease after recurrence or progression following a non-steroidal aromatase inhibitor. In the U.S., Afinitor is approved for the treatment of postmenopausal women with advanced hormone receptor-positive, HER2-negative breast cancer (advanced HR+ breast cancer) in combination with exemestane after failure of treatment with letrozole or anastrozole.

Afinitor (everolimus) tablets are approved in the oncology settings of advanced renal cell carcinoma after progression of or after vascular endothelial growth factor (VEGF)-targeted therapy in over 80 countries including the United States and throughout the European Union. In the U.S. and in the E.U. it is approved for locally advanced, metastatic or unresectable progressive neuroendocrine tumors of pancreatic origin.

Novartis Everolimus is also available for use in non-oncology patients under the brand names Afinitor or Votubia, Certican and Zortress. Abbott holds the exclusive license, with Boston Scientific holding a sublicense for use in drug-eluting stents.

Indications are different in various countries and not all indications are available in every country. Everolismus safety and efficacy profile has not yet been established outside the approved indications and due to the uncertainty of clinical trials; it remains uncertain whether everolimus will become commercially available for additional indications in other countries in the world.

Written by Grace Rattue