The Medicines and Healthcare products Regulatory Agency (MHRA) has authorised anastrozole to prevent post-menopausal women at a moderate or high risk of breast cancer from developing the disease.
The hormone treatment has already been authorised to treat breast cancer in post-menopausal women and has been used off-label for prevention.
Breast cancer is one of the most common cancers in England, with around 47,000 new cases every year.
The decision was based on results from the international, randomised, double-blind, placebo-controlled IBIS-II trial, which showed that fewer women developed breast cancer when taking anastrozole compared to a placebo group.
Taken as a 1mg tablet once a day for five years, anastrozole is an aromatase inhibitor that works by reducing the amount of oestrogen in the body by blocking an enzyme known as aromatase.
Following the MHRA’s authorisation, anastrozole is estimated to help prevent around 2,000 cases of breast cancer in England.
Additionally, the NHS would be saving around £15m in treatment costs.
The treatment is the first medicine to be repurposed through the NHS’s Medicines Repurposing Programme, a programme set up in 2021 that looks at existing medicines in new ways to benefit patients and the NHS.
The programme is supported by the Department of Health and Social Care, MHRA, the National Institute for Health and Care Excellence and the National Institute for Health and Care Research.
Anastrozole was licensed by Accord Healthcare on a not-for-profit basis after being selected through an open competitive process as part of the programme.
The Medicines Repurposing Programme will work with the MHRA and the British Generic Manufacturers Association to establish that other companies which supply the treatment adopt its new licensed indication.
Dame June Raine, chief executive of the MHRA, said that the programme “is essential to support and advance research into medicines that might be repurposed”.
“The MHRA welcomes applications for repurposed medicines and encourages early dialogue from companies or developers considering this,” she said.
NHS chief executive, Amanda Pritchard, said: “We hope that licensing anastrozole for a new use today represents the first step to ensuring this risk-reducing option can be accessed by all who could benefit from it.”