Specialist nurses and charities have welcomed an announcement that the breast cancer drug anastrozole has been ‘repurposed’ for use to prevent the disease in England.
Tens of thousands of women at increased risk of breast cancer could benefit from the risk-reducing drug on the NHS, according to NHS England.
Anastrozole, available already for many years as a breast cancer treatment, has today been licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) for prevention.
“Today’s news about anastrozole is a huge step forward”
The drug is taken daily as a 1mg tablet for five years. It is an aromatase inhibitor, which works by reducing the amount of oestrogen that the body makes by blocking the enzyme aromatase.
The most common side effects of the medication are hot flushes, feeling weak, pain or stiffness in the joints, arthritis, skin rash, nausea, headache, osteoporosis and depression.
Around 289,000 women at moderate or high risk of breast cancer could be eligible for the drug as a preventative, according to modelling by NHS England.
While not all will choose to take it, the National Institute for Health and Care Excellence (NICE) has estimated that, if 25% do so, around 2,000 breast cancer cases could potentially be prevented.
Anastrozole, which is now off-patent, has been shown in trials to reduce the incidence of the disease in post-menopausal women at increased risk of the disease by almost 50%.
It was first recommended as a preventive option for breast cancer by NICE back in 2017, but uptake remained low due to it previously being unlicensed for this particular use.
The drug has today been granted a new indication by the MHRA as a preventive option for women at increased risk, including those with a significant family history of the disease.
The move was facilitated via a pioneering programme led by NHS England and involving a number of national bodies including NICE, the MHRA and the National Institute for Health and Care Research.
Anastrozole is the first medicine to be repurposed through the new multi-agency Medicines Repurposing Programme, which looks at using existing medicines in new ways for the NHS.
The programme, set up in 2021, builds on the innovation in medicines repurposing seen during the Covid-19 pandemic, said NHS England.
For example, it cited tocilizumab, an arthritis drug, and dexamethasone, a widely available steroid, that had been repurposed as treatments for Covid-19.
“This paves the way for improving access to risk-reducing drugs”
Dany Bell, nurse and strategic adviser for treatment, medicines and genomics at Macmillan Cancer Support, said: “Knowing that you have an increased risk of developing breast cancer can be difficult to deal with, so today’s news about anastrozole is a huge step forward.
“It will help reduce anxiety while reducing overall risk,” she said, but added: “It’s important to note that the drug is only available to those who are post-menopausal.”
Baroness Delyth Morgan, chief executive of the charity Breast Cancer Now, said: “The extension of anastrozole’s licence to cover it being used as a risk-reducing treatment is a major step forward.
“Anastrozole was the first drug to be supported by the Medicines Repurposing Programme and this paves the way for improving access to risk-reducing drugs.
“We look forward to continuing our work with NHS England to further improve access to these drugs for everyone eligible,” she added.
NHS England chief executive Amanda Pritchard said: “It’s fantastic that this vital risk-reducing option could now help thousands of women and their families avoid the distress of a breast cancer diagnosis.
“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,” she said.
“This is the first drug to be repurposed though a world-leading new programme to help us realise the full potential of existing medicines in new uses to save and improve more lives on the NHS.
“Thanks to this initiative, we hope that greater access to anastrozole could enable more women to take risk-reducing steps if they’d like to, helping them live without fear of breast cancer,” she added.