Researchers say a new type of drug that blocks a receptor in the brain could provide relief for women going through menopause.

There’s good news for women going through menopause, if you can wait three years or so.

Researchers say they’ve discovered that an experimental class of drugs that blocks a key receptor in the brain might be a new, effective treatment for common menopause symptoms.

However, the drug apparently causes health problems with the liver, so the drug’s manufacturer is reformulating the medication.

The manufacturer is scheduled to launch new clinical trials soon in the United States and Europe. It expects to bring the modified drug to market in about three years.

Menopause typically begins in women between 45 and 55 years of age, when estrogen levels naturally decline.

Hormone replacement therapy (HRT) is the conventional treatment. But many women are reluctant to receive HRT.

“The 2002 media hype about the risks of hormone therapy continue to concern women and providers. Because of this, some women prefer not to take HRT medication and avoid risks like breast cancer, blood clots, stroke, or heart disease,” said Dr. JoAnn V. Pinkerton, NCMP, executive director of the North American Menopause Society.

A new trial published in the journal Menopause indicates that a drug called MLE4901 (Pavinetant) could soon be the first new treatment for vasomotor symptoms (VMS) such as night sweats and hot flashes since HRT was introduced in the 1960s.

The trial involved 37 menopausal women between 40 and 62 years of age who experienced seven or more hot flashes per day.

MLE4901, which was first investigated as a treatment for polycystic ovary syndrome (PCOS) and schizophrenia, is nonhormonal and blocks a receptor in the brain called NKB, which is linked to hot flashes.

“As NKB has many targets of action within the brain, the potential to really improve many of the symptoms of menopause, such as hot flushes, difficulty sleeping, weight gain, and poor concentration, is huge. To see the lives of our participants change so dramatically and so quickly was so exciting and suggests great promise for the future of this type of treatment,” said Dr. Julia Prague of Imperial College London and lead author of the study in a press release.

Waljit S. Dhillo, PhD, professor of endocrinology and metabolism at Imperial College London and a principal investigator of the study, found that by the third day of treatment, MLE4901 had reduced the frequency of hot flashes by about 50 percent, compared with the placebo group.

The participants who received the drug also experienced significantly reduced hot flash severity and improvements in both sleep quality and focus. These benefits were maintained for the duration of the four-week study.

“We already knew this compound could be a game-changer for menopausal women and get rid of three-quarters of their hot flashes in four weeks. But this new analysis confirms the beneficial effect is obtained very quickly — within just three days,” Dhillo said in a press release.

“The current standards of therapy, including hormone replacement therapy (HRT), selective serotonin reuptake inhibitors (SSRIs), and over-the-counter treatments, all have tradeoffs between safety and efficacy, such as an increased risk of breast and endometrial cancers,” Dhillo said in a statement from last year.

“While larger scale studies of longer duration will be needed, this study has demonstrated the practice-changing capacity of MLE4901 to treat hot flush symptoms without the need for estrogen exposure,” he said.

However, this specific drug won’t undergo further trials.

While taking MLE4901 doesn’t carry the risks of HRT, it has been shown to harm liver function.

Two similar compounds that can block NKB without affecting the liver have entered larger patient trials.

One of these trials was launched in the United States last year.

“NKB inhibitors may be the best option for women who have had breast cancer or who fear breast cancer or have other contraindications to hormone therapy, such as increased risk of blood clots, heart disease, or stroke, or who have symptoms persisting for longer durations or starting up again after age 60,” Pinkerton said.