A Study to Learn More About How Well Elinzanetant Works and How Safe it is Compared to Placebo for the Treatment of Hot Flashes Caused by Anti-cancer Therapy in Women With, or at High Risk for Developing Hormone-receptor Positive Breast Cancer

Mean Change in Severity of Moderate to Severe HF From Baseline to Week 4 (Assessed by HFDD).

In the HFDD, the severity of HFs was categorized as: 1 = mild, 2 = moderate, and 3 = severe; therefore, a decrease in the HF severity score indicates an improvement. The mean daily severity during treatment was calculated for the available days as \[(1 x number of mild HF) + (2 x number of moderate HF) + (3 x number of severe HF)\] / (total number of mild, moderate and severe hot flashes on that day). When no HFs were reported for a particular day, the mean severity for that day was set to 0. The mean daily severity during baseline was calculated for the available days as \[(2 x number of moderate HF) + (3 x number of severe HF)\] / (total number of moderate to severe hot flashes on that day).

Time frame: Baseline to Week 4

Mean Change in Severity of Moderate to Severe HF From Baseline to Week 12 (Assessed by HFDD)

In the HFDD, the severity of HFs was categorized as: 1 = mild, 2 = moderate, and 3 = severe; therefore, a decrease in the HF severity score indicates an improvement. The mean daily severity during treatment was calculated for the available days as \[(1 x number of mild HF) + (2 x number of moderate HF) + (3 x number of severe HF)\] / (total number of mild, moderate and severe hot flashes on that day). When no HFs were reported for a particular day, the mean severity for that day was set to 0. The mean daily severity during baseline was calculated for the available days as \[(2 x number of moderate HF) + (3 x number of severe HF)\] / (total number of moderate to severe hot flashes on that day).

Time frame: Baseline to Week 12

Mean Change in Frequency of Moderate to Severe HF From Baseline to Week 1 (Assessed by HFDD)

Participants' assessments of HF were recorded electronically twice daily using the sponsor developed Hot Flash Daily Diary (HFDD). The HFDD was completed in the morning after waking up (morning diary) and each evening at bedtime (evening diary) on the hand-held device. The HFDD items assessed the number of mild, moderate, and severe HF experienced during the day and during the night. Mild HF was defined as a "sensation of heat without sweating", moderate HF was defined as a "sensation of heat with sweating, but able to continue activity", and severe HF was defined as a "sensation of heat with sweating, causing cessation (stopping) of activity". Mean daily frequency is calculated as total number of moderate to severe HF during that week divided by the total number of available days with data during that week.

Time frame: Baseline to Week 1

Mean Change in Frequency of Moderate to Severe HF From Baseline Over Time (Assessed by HFDD)

Participants' assessments of HF were recorded electronically twice daily using the sponsor developed Hot Flash Daily Diary (HFDD). The HFDD was completed in the morning after waking up (morning diary) and each evening at bedtime (evening diary) on the hand-held device. The HFDD items assessed the number of mild, moderate, and severe HF experienced during the day and during the night. Mild HF was defined as a "sensation of heat without sweating", moderate HF was defined as a "sensation of heat with sweating, but able to continue activity", and severe HF was defined as a "sensation of heat with sweating, causing cessation (stopping) of activity". Mean daily frequency is calculated as total number of moderate to severe HF during that week divided by the total number of available days with data during that week.

Time frame: Baseline to Week 50

Mean Change in Patient-reported Outcomes Measurement Information System Sleep Disturbance Short Form 8b (PROMIS SD SF 8b) Total Score From Baseline to Week 12

The PROMIS SD SF 8b includes 8 items assessing sleep disturbance over the past 7 days. Items assess sleep quality, sleep depth and restoration associated with sleep, perceived difficulties with getting to sleep or staying asleep and perceptions of the adequacy of and satisfaction with sleep. Participants respond to the items on a 5-point scale from "not at all", "never" or "very poor" to "very much", "always" or "very good". Four of the items are scored reversely. Individual item scores are aggregated to total raw scores which range from 8 to 40. Total raw scores are converted into T-scores for comparison with population norms, with a mean of 50 and standard deviation of 10. T-scores range from 28.9 to 76.5. For both raw and T-scores higher scores indicate greater severity of sleep disturbance. According to available score cut points from PROMIS developers, T-scores can be interpreted as indicating mild (55-59), moderate (60-69), or severe (\>70) sleep disturbance.

Time frame: Baseline to Week 12

Mean Change in Menopause Specific Quality of Life Scale (MENQOL) Total Score From Baseline to Week 12

The MENQOL questionnaire is comprised of 29 items assessing the presence of menopausal symptoms and the impact of menopause on health-related quality of life over the past week. The items assess four domains of symptoms and functioning: VMS, psychosocial functioning, physical functioning, and sexual functioning. For each item, the participant indicates if they have experienced the symptom (yes/no). If participants select yes, participants rate how bothered they were by the symptom using a six-point verbal descriptor scale, with response options ranging from 0 'not at all bothered' to 6 'extremely bothered'. Based on the individual responses, item scores, domain scores, and a total MENQOL score are calculated. Each score ranges from 1-8, higher scores indicate greater bother. For a MENQOL total score, the aggregated mean of the mean domain scores is calculated.

Time frame: Baseline to Week 12