Afinitor® (everolimus) tablets, in combination with an aromatase inhibitor, has been approved for use by the European Commission.
Dr Rachel Greig, Senior Policy Officer at Breakthrough Breast Cancer, said: “Everolimus is one of the biggest advances in breast cancer treatment in many years. This drug could make a massive difference to thousands of patients with advanced breast cancer. While this is by no means a cure, it could give patients several extra months of good quality of life with their families.
“Everolimus needs to be assessed by Nice but we are strongly backing it to be made available for those who need it.”
In the UK, breast cancer is the most common form of cancer in women, accounting for approximately 31% of all new cancer cases. It is estimated that some 30,492 women have the advanced breast cancer form7, . In terms of the patient population in which everolimus is approved it is thought that up to 14,000 patients could benefit from the therapy.
Advanced breast cancer is an incurable disease and current estimated life expectancy for patients is approximately 18-36 months after diagnosis . The most common form of advanced breast cancer is the oestrogen receptor-positive type which accounts for approximately 75% of all breast cancers . The current cornerstone of treatment for women with advanced hormone breast cancer is endocrine therapy, but most will eventually develop treatment resistance to endocrine therapies such as aromatase inhibitors. Resistance to endocrine therapy is linked to disease progression.
“The benefit of endocrine therapy has always been limited by the eventual development of acquired resistance. For the first time clinical research has identified a therapeutic agent, everolimus, which in combination with exemestane can seemingly circumvent this treatment resistance and substantially reduce the risk of patients cancers worsening,” said Professor Stephen Johnston, Professor of Breast Cancer Medicine, The Royal Marsden NHS Foundation Trust. “Everolimus has the potential to redefine the way this common form of advanced breast cancer is treated and importantly offers women an effective alternative to a chemotherapy regime,” he added.
First mTOR inhibitor approved in HR+ breast cancer
mTOR (mammalian target of rapamycin) is a protein that acts as an important regulator of tumour cell division, blood vessel growth and cell metabolism. When the mTOR pathway is overactivated resistance to endocrine therapy increases and tumours grow. Afinitor inhibits the mTOR protein thus slowing down cancer cell growth and boosts the efficacy of endocrine therapy.
“mTOR is an exciting new target protein in cancer management and seems to act as a 'master switch' because of its involvement in a number of cancers. Everolimus is the first licenced mTOR inhibitor in breast cancer and we have already seen the benefits of targeting this pathway in kidney and pancreatic neuroendocrine cancers. The potential for effectively targeting this pathway in breast cancer is very exciting,” said Dr Alison Jones, Consultant Medical Oncologist, Royal Free Hospital and University College London.