Women plagued by frequent hot flushes during the menopause could cut the number of flushes by almost three–quarters, thanks to a new drug compound.

In a trial carried out at Imperial College London, researchers showed that women who suffered seven or more hot flushes a day could reduce the number by as much as 73 per cent, as well as reducing their severity and impact.

The team hopes that this successful early–stage study, published in The Lancet and involving a drug which targets receptors in the brain, could provide hope for women who are affected by flushes and for whom hormone replacement therapy (HRT) is either unsuitable or not preferred by the patient due to safety concerns.

In the latest study, which was funded by the MRC and NIHR and led by Professor Dhillo, 28 women with severe flushing were given a new drug compound called MLE4901, originally developed by AstraZeneca and licensed to Millendo Therapeutics, to try to relieve their symptoms.

At the heart of the approach is blocking a chemical called neurokinin B (NKB). Previous studies in animals revealed that increased levels of the chemical caused a flushing response in the tails of rats similar to a menopausal flush.

In human studies, analysis of brain tissue from post–menopausal women revealed elevated levels of NKB in their brains. The Imperial team has previously found that giving NKB to younger women in a temperature–controlled room caused flushing.

Bringing together all of these strands led the researchers to think that blocking the action of the chemical could potentially have the opposite effect and be a new effective treatment for menopausal flushing.

To test the idea, female volunteers with frequent flushing were administered MLE4901 which blocks the NK3 receptors of the brain, where NKB acts, to supress the action of the chemical.

In a randomised, double–blind, placebo–controlled trial, menopausal women aged between 40 and 62 years old – and who experienced seven or more hot flushes a day and had not had a period in at least 12 months – were recruited at Imperial College Healthcare NHS Trust hospitals.

Participants were randomly chosen to either first receive a 80 mg daily dose of the drug or a placebo over the course of a four week period, before switching to receive the other tablet for an additional four weeks. This ensured the women acted as their own controls during the study, and the effects of the drug were clear.

The researchers found that the compound MLE4901 significantly reduced the average total number of flushes during the four–week treatment period, as well as their severity, compared to when the patients received the placebo for four weeks. It also helped to reduce the impact of flushes on the women’s lives, improving sleep.

Treatment with an NK3 receptor blocker could be ideal for women who can’t take hormone replacement therapy (HRT), due to increased risk of breast cancer or clots or those that prefer not to take it because of safety concerns.

The findings were presented at the annual meeting of the Endocrine Society, ENDO 2017.