Putting Innovation Into Practice: Managing CDK4/6 Inhibitors

Breast Cancer Awareness Month, observed each year in October, recognizes the research, advocacy, and strength of patients that have led to treatment advances for the most common cancer diagnosis in women. The Association of Cancer Care Centers (ACCC) recognizes that these advances are only effective if they are available to all patients. To this end, ACCC has created several resources to support cancer centers offering cyclin-dependent kinase (CDK) 4/6 inhibitors to patients with hormone receptor-positive (HR+)/ HER2-negative (HER2–) breast cancer.

HR+/HER2– breast cancer is the most common subtype of breast cancer, making up 70% of new cases in the US, according to the National Cancer Institute. CDK4/6 inhibitors are the standard-of-care treatment for this cancer type, offering longer survival and lower rates of recurrence through oral therapy rather than infusion. However, they also come with a high risk of adverse events (AEs), including gastrointestinal problems, cytopenias, and heartrate irregularities called QTc prolongation. Managing these toxicities is a significant barrier to offering CDK4/6 inhibitors as a treatment option at some cancer centers. 

This year, ACCC worked with 3 different cancer centers that have successfully implemented CDK4/6 inhibitors to profile their successes, challenges, and solutions to common problems with this drug type. Here are the top takeaways from each center.

Clinical Pharmacy Specialist Leading AE Management

Miami Cancer Institute (MCI), part of Baptist Health South Florida, found that pharmacists were the members of their team best equipped to manage CDK4/6 toxicities. Their team of 9 breast oncologists is supported by 2 dedicated breast pharmacists, 1 at each clinic site, who act as first responders to AEs for patients. Pharmacists proactively call patients at regular intervals to check on their status and closely monitor lab results. They directly advise patients on diet, hydration, exercise, and other holistic management strategies, and collaborate with oncologists to adjust dosage when necessary. 

The goal is to identify AEs early and intervene before they become severe or lead to discontinuation of treatment. Open and frequent communication between patients and providers is key to this proactive approach. “Patients need someone they can contact before symptoms become serious,” said Diana Van Ostran, PharmD, BCOP, clinical pharmacy specialist in the breast clinic at MCI. Read the full spotlight on MCI’s CDK4/6 inhibitor management to learn more about how this cancer center tailored the clinical pharmacist role to fulfill this need.

Proactive Toxicity Management

At Atrium Health Levine Cancer (AHLC), oncologists begin evaluating patients for AEs before CDK4/6 inhibitors are even prescribed. Factors such as age, disease burden, and performance status all affect the likelihood of developing serious AEs. Providers discuss these risks, along with patient preferences and financial considerations, to tailor medication and dosage to each individual, sometimes opting for endocrine therapy alone rather than adding a CDK4/6 inhibitor. 

This proactive attitude continues into treatment once patients begin initial cycles of therapy. Like MCI, AHLC calls patients at regular intervals to identify and assess severity of AEs. Providers also send patients home with prescriptions and over-the-counter recommendations for management. For example, loperamide, an antidiarrheal medication, is routinely provided to patients prescribed the CDK4/6 inhibitor abemaciclib. Patients are encouraged to begin taking loperamide at the first sign of loose stool, reducing time to AE management and allowing patients to continue their daily activities. For more examples of this cancer center’s proactive management strategies, read the AHLC practice spotlight. 

Tailoring Care to Community Needs 

George Washington (GW) Cancer Center sees patients from a racially, ethnically, and socioeconomically diverse region spanning Washington, DC; Maryland; and northern Virginia. This patient population faces wide-ranging disparities and barriers to care and GW Cancer Center employs a patient navigator to address these barriers. 

The patient navigator fills a similar role to a nurse navigator, helping patients to understand their diagnoses and treatment, access support services, and schedule appointments. However, patient navigators are community members rather than providers. This allows them to better relate to patients, understand community values and challenges, and develop trust. This team at GW Cancer Center has found that patients are better able to understand their treatment options and communicate concerns with support from the patient navigator. The practice spotlight on GW Cancer Center goes into further detail on this unique role and how it contributes to successful implementation of CDK4/6 inhibitors. 

Diverse Approaches to Breast Cancer Care 

Each cancer center profiled by ACCC has a unique staff and patient population. There is no one-size-fits-all approach, but rather individual strategies that can be tailored to the needs, resources, and strengths of individual clinics. The tools produced in this initiative celebrate the success of these cancer centers while providing actionable steps for making CDK4/6 inhibitors available at any institution. By empowering cancer centers to expand their treatment offerings, ACCC is doing its part to make effective treatment options available and accessible to patients with breast cancer everywhere. 

Resources: 

• CDK Inhibitors Management 
• Infographic: Adverse Event Management for CDK Inhibitors in Hormone Receptor–Positive Breast Cancer