Imlunestrant for adjuvant treatment of ER-positive, HER2-negative early breast cancer with increased risk of recurrence

Imlunestrant is in development for treatment of patients with oestrogen receptor positive (ER+), human epidermal receptor 2 negative (HER2-) early breast cancer with increased risk of recurrence. Breast cancer occurs when abnormal cells in the breast begin to grow in an uncontrolled way and eventually form a tumour. Early stage breast cancer means the cancer has not spread to other parts of the body. ER+ breast cancer is a type of breast cancer that grows in response to the hormone oestrogen. HER2- breast cancers have little or none of the HER2 protein on their cancer cells. This type of cancer often responds to hormone (endocrine) treatments that block or lower oestrogen. However, up to a third of people eventually have the cancer come back during or after follow-on hormone treatment. Many patients also pause or stop treatment early because of side effects or safety concerns, thereby increasing the risk of death. These limitations show the need for more effective treatment options with fewer side effects to prevent or delay the disease coming back.