Endocrine Therapy + CDK4/6 Inhibitor for Breast Cancer

This trial aims to identify which patients with metastatic breast cancer respond to a combination of endocrine therapy and a CDK4/6 inhibitor, a type of cancer treatment. Researchers will analyze tumor tissues and blood samples to understand how and why these treatments succeed or fail. The ultimate goal is to tailor breast cancer treatments more effectively. Suitable candidates include men and women with newly diagnosed metastatic breast cancer that is estrogen or progesterone receptor positive and are receiving treatment at Johns Hopkins. As a Phase 2 trial, the research focuses on assessing the treatment's effectiveness in an initial, smaller group of participants.

The trial protocol does not specify if you need to stop taking your current medications. However, premenopausal women and men must take a luteinizing hormone-releasing hormone (LHRH) agonist alongside the trial treatment.

Research has shown that CDK4/6 inhibitors, like palbociclib, are usually well-tolerated by patients. These drugs can sometimes cause side effects, such as a decrease in white blood cells, which may increase the risk of infection. However, regular check-ups and dose adjustments often manage these side effects.

Almost everyone undergoing hormone therapy experiences some side effects, with hot flashes and joint pain being the most common. Despite these side effects, many patients continue treatment because it can significantly improve survival rates in breast cancer.

Researchers are excited about the combination of endocrine therapy and CDK4/6 inhibitors for breast cancer because of its unique dual-action approach. Unlike standard treatments that often target hormones alone, this combination not only interferes with hormone-driven cancer growth but also targets the CDK4/6 pathway, which is crucial for cancer cell division. This dual mechanism could potentially improve the effectiveness of treatment, especially in patients with metastatic breast cancer, offering hope for better disease control and longer progression-free survival.

This trial will evaluate the combination of a CDK4/6 inhibitor with hormone therapy for treating advanced breast cancer. Studies have shown that this combination extends patient survival compared to hormone therapy alone. Research indicates that this treatment is effective for individuals of all ages, regardless of menopausal status, and even if the cancer has metastasized. It appears to improve outcomes for patients who have not yet received treatment for advanced breast cancer. Overall, combining CDK4/6 inhibitors with hormone therapy offers a promising option for managing hormone receptor-positive breast cancer.⁶⁷⁸⁹¹⁰