A study to find out if fezolinetant helps reduce moderate to severe hot flashes in women going through menopause

This study was for women in menopause with moderate to severe hot flashes. Menopause, a normal part of aging, is the time of a woman’s last period. Hot flashes can interrupt a woman’s daily life. The study treatments were fezolinetant 30 milligrams (mg) (1 tablet of fezolinetant and 1 placebo tablet) once a day, fezolinetant 45 mg (2 tablets of fezolinetant) once a day or placebo (2 tablets) once a day. (Placebo was a dummy treatment that looks like medicine but did not had any medicine in it.) The study compared fezolinetant and placebo after 4 and 12 weeks of dosing. The study evaluated if fezolinetant reduces the number of hot flashes. And the study evaluated if fezolinetant reduces the severity of the hot flashes. Women in the study received an electronic handheld device at the first study visit. (It was similar to a smart phone.) Each day of the study, study participants used this to record their hot flashes. Their record for the 10 days before the start of study treatment was checked. They remained in the study if their record shown 7 or 8 moderate to severe hot flashes per day (50 or more per week). Next, they were picked for 1 of the 2 study treatments (fezolinetant or placebo) by chance alone. It was like flipping a coin. The study participants took study treatment for 52 weeks. The first 12 weeks of study treatment are “double-blinded.” That means that the study participants and the study doctors did not knew who took which of the study treatments (fezolinetant 30 mg, fezolinetant 45 mg or placebo) during that time. The last 40 weeks of study treatment are “noncontrolled.” That means that each study participant and the study doctors knew which study treatment that study participant took during that time. Women who took fezolinetant during the first 12 weeks continued to take the same dose. Women who took placebo during the first 12 weeks took fezolinetant. Their dose was either 30 mg or 45 mg fezolinetant. At weeks 2, 4, 8, 12, 14, 16 and then once a month, the study participants visited the hospital or clinic for a check-up. They were asked about medications, side effects and how they felt. Other checks included physical exam and vital signs (heart rate, temperature and blood pressure). Blood and urine was collected for laboratory tests. Study participants completed questionnaires that were about how hot flashes affect their daily life. Study participants who still had their uterus had the following 2 tests done at the first and last study visits. One of the 2 tests was endometrial biopsy. This test involves removing a small amount of tissue from the inside lining of the uterus. The tissue was then checked under a microscope. The other test is transvaginal ultrasound. This test used sound waves to create pictures of the organs in the pelvis. The sound waves were transmitted by a probe (transducer), which was placed inside the vagina. Study participants may have a screening mammogram done at the first and/or last study visit. A mammogram is an x-ray picture of the breasts used to screen for breast cancer. Study participants who did not had this test done in the last 12 months had it done at the first study visit. They had it done at the last study visit if they are due for their screening mammogram and their own doctor agrees. The last check-up at the hospital or clinic was 3 weeks after the last dose of study treatment.