CDK4/6 Inhibitor Selection in HR+/HER2– Breast Cancer

When choosing a CDK4/6 inhibitor for patients with hormone receptor (HR)–positive, HER2-negative metastatic breast cancer in the first-line setting, it is essential to match therapy to a patient’s comorbidities and risk factors, according to Courtney Moore, APRN, FNP-C, OCN, a nurse practitioner at Norton Cancer Institute Medical Oncology and Hematology in Louisville, Kentucky.

In an interview with Oncology Nursing News following a Case-Based Roundtable discussion on this topic, Moore highlighted that the safety profiles of CDK4/6 inhibitors can guide drug selection. For example, both palbociclib (Ibrance) and abemaciclib (Verzenio) are associated with neutropenia, which is especially important to consider for patients receiving immunosuppressive therapies or those with autoimmune or rheumatologic conditions. Close monitoring may be required to mitigate risk in these cases.

Moore also emphasized that ribociclib (Kisqali) carries the potential for cardiac adverse effects, particularly QTc prolongation. For patients with preexisting arrhythmias, such as atrial fibrillation, this agent may not be the optimal choice.

Ultimately, Moore explained, individualized selection of CDK4/6 inhibitors requires careful assessment of patient history and comorbidities. Oncology nurses and advanced practice providers play a critical role in tailoring therapy and monitoring patients closely throughout treatment.

Transcript

The risk factors tie into the adverse effect profile of these medications, between the CDK4/6 inhibitors, there are a couple that lean more towards neutropenia as a major adverse effect. Therefore, we want to be aware of if the patient is on any immunosuppressive therapies or has any other rheumatologic disorders or autoimmune disorders, so that we can keep a close eye on them, as well as one of the medications, ribociclib has the potential to have some heart adverse effects to it. If we have patients that already have arrhythmias such as atrial fibrillation, we want to avoid [ribociclib], because it can prolong the QTc interval. Being aware of your patient and what other comorbidities they may have is very important when you’re [deciding what CDK4/6 inhibitor is best].

This transcript has been edited for clarity and conciseness.