An experimental hormone-free drug shows promise against menopausal hot flashes

Around 80% of menopausal women suffer from hot flashes, a sudden sensation of heat that in 25% of cases is a major obstacle to continuing with daily activities. To avoid this and other symptoms of menopause, hormone treatments are available to compensate for the decrease in their natural production. However, some women, such as those who have had breast tumors whose growth is sensitive to the presence of hormones, cannot receive these therapies. Furthermore, many women and even some doctors are reluctant to use hormonal treatments.

A few days ago, The Lancet published the results of a study that may offer alternatives to women who want to avoid hot flashes but cannot or do not want to receive hormone replacement therapy. The work tested a drug called fezolinetant, a molecule capable of blocking the neurokinin-3 receptor, a fundamental piece of the communication system with the spot in the brain where temperature is regulated, in the hypothalamus. At that spot, the drop in estrogen is interpreted as a drop in temperature and a defense signal is sent to make the blood vessels in the skin dilate, which the woman perceives as a sudden flush. Fezolinetant blocks that miscommunication quite successfully.

The trial recruited 2,205 women and assigned them to several groups with different doses of the substance, including one that received a placebo. The frequency of symptoms was reduced by slightly more than 50% compared to the placebo group, a figure that, according to Antonio Cano, head of the Obstetrics and Gynecology service at Spain’s Hospital Clínico Universitario de Valencia and co-author of the study, “would be just a little below what hormonal treatments offer.” Cano considers that, barring women who have had some type of tumor, “the treatment that should be used in the general population is hormonal,” although it could be a second option for women who refuse this type of treatment.

“It would be a second option that does not reach the efficacy levels of hormonal treatment, but is still well above other treatments that have practically no proven efficacy, such as phytoestrogens or serotonin reuptake inhibitors [commonly used for depression], which are used by many women with breast cancer, but do not have significant efficacy,” explains Cano.

No data on sexual life

Silvia González, spokesperson for the Association for the Study of Menopause, says that the results “are promising, although important data on quality of life, mood disorders and sexual desire are missing.” This gynecologist believes that “it can be an alternative” although “hormonal therapy works somewhat better, especially for intense symptoms.” With drugs such as fezolinetant, other combination treatments for symptoms of menopause such as vaginal dryness would be necessary.

Like Cano, González agrees that the new drug offers significant advantages over other existing alternatives to hormone therapy, including anti-depressants, which are sometimes prescribed in lower doses than those prescribed for depression, González explains. “But patients are often not happy about it, and tell me: ‘But I am not depressed’,” she notes.

The new drug, developed by the pharmaceutical company Astellas, is being reviewed for approval by regulatory agencies in the coming months, but no date is yet known. In the meantime, experts note that menopausal symptoms should not be something that women feel they just have to put up with. “There are moderate hot flashes, but the intense ones, for women who are still of working age, can be a problem, and awareness about menopause at work is an important issue that we have to find solutions for,” says Cano.

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