Pharmacist Managing CDK4/6 Inhibitor Therapy in Breast Cancer: Practical Guidance for Pharmacists

In this interview, Danielle Roman, PharmD, BCOP, discusses the role of CDK4/6 inhibitors in both early-stage and metastatic hormone receptor–positive, HER2-negative breast cancer. She highlights how this drug class has transformed treatment, improving outcomes for patients with high-risk disease in the early-stage setting and serving as a standard option for nearly all patients in the metastatic setting. Roman explains that pharmacists play a key role in supporting patient adherence by guiding dose reductions or therapy holds when needed, ensuring patients can remain on treatment longer. She also notes that pharmacists should be well versed in the different dosing schedules, duration of therapy recommendations, and adverse effect profiles across agents in this class to better advise the health care team and optimize patient care.

Pharmacy Times: Can you share the topic of your discussion today? What significance do CDK4/6 inhibitors play in this setting?

Danielle Roman, PharmD, BCOP: We discuss the use of the CDK4/6 inhibitor class for both early-stage and metastatic hormone receptor–positive, HER2-negative breast cancer. This drug class has really revolutionized the way we treat breast cancer. In the early-stage setting, its use is primarily for patients with high-risk disease, and it has helped improve outcomes for those patients. In the metastatic setting, we are using it primarily for all patients with the hormone receptor–positive, HER2-negative subtype.

Pharmacy Times: Where do you see gaps in real-world evidence compared with clinical trial data, and how might pharmacists contribute to filling those gaps?

Roman: Gaps exist in being able to keep patients on therapy, as well as in identifying ways to achieve that. When it comes to deciding whether dose reductions or holding therapy are necessary, pharmacists are really well positioned to know when to make those adjustments. They can help the health care team by providing advice on holding therapy or reducing doses so that patients can remain on therapy for longer periods of time.

Pharmacy Times: What are some key points pharmacists should know about managing CDK4/6 regimens in these patients?

Roman: Pharmacists should be well aware of the dosing schedules for these agents, as there are key differences within this drug class. Some are given three weeks on and one week off, while others are administered on a continuous basis. It is also important to recognize that recommendations differ for the duration of therapy in the early-stage setting. In terms of adverse effect profiles, there are similarities among the agents in this class, but also important differences. Pharmacists are well positioned to help the health care team understand these aspects of care.