Pembrolizumab in combination with neoadjuvant chemotherapy and adjuvant endocrine therapy is in clinical development for the treatment of early-stage Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative (ER+/HER2-) breast cancer. Early breast cancer is where the disease is limited to the breast region and has not spread to other parts of the body. Treatment of early-stage breast cancer usually involves surgery. Most patients will often receive some treatment after (‘adjuvant’) the surgery to improve the success rate of the treatment. Treatment with medicines prior to surgery (neoadjuvant) may provide better long-term survival prospects for patients with early-stage operable breast cancer.
Pembrolizumab is a drug administered intravenously (IV) that binds to the programmed cell death-1 (PD-1) receptor and improves the activity of the immune system to kill cancer cells. If licenced, pembrolizumab in combination with neoadjuvant chemotherapy and adjuvant endocrine therapy would provide an additional treatment option for ER+/HER2- breast cancer.