Nurse Practitioner Outlines CDK4/6 Inhibitor Toxicity in HR+ Breast Cancer

In addition to managing toxicities such as arthralgia, it is important to ensure that patients with hormone receptor–positive breast cancer are exercising often so that they can mitigate fatigue associated with CDK4/6 inhibitor treatment, including agents such as palbociclib (Ibrance) and ribociclib (Kisqali), said Sarah Donahue, MPH, NP.

In a conversation with CancerNetwork®, Donahue, a nurse practitioner at University of California, San Francisco, and part of the Oncology Nursing Society, also described the toxicity profile of abemaciclib (Verzenios) in the treatment of the aforementioned patient population. With abemaciclib, she stated that adverse effects like diarrhea could be managed with loperamide, if needed.

Transcript:

Palbociclib and ribociclib can both cause neutropenia. We’re giving patients 3-weeks-on, 1-week-off treatment for that reason, and we’re checking labs a lot. They can both cause fatigue, and they can both cause mouth sores. They’re always given with hormone therapy, so the [adverse] effects of the hormone therapy can be added on; usually it’s fulvestrant or an aromatase inhibitor. It may [cause] hot flashes if it’s the fulvestrant, or it might be arthralgia and hot flashes for aromatase inhibitors. They all come together. What I drive home with patients is that these are first-line therapies for [those with] hormone receptor–positive metastatic breast cancer.

We need to make sure that [patients are] active and exercising a lot. That really helps with the fatigue, and the arthralgia from the aromatase inhibitors. We make sure to treat their hot flashes, especially if they are leading to any sort of insomnia.

With abemaciclib, I’m generally not using that in the first line. It’s more of a second-line therapy that has more diarrhea with it and less of the decreased counts. Patients can take [abemaciclib] continuously without a break, so the labs don’t get affected as much. But the diarrhea can be pretty tough in the beginning for some patients, [so I] make sure that they’re using their loperamide as needed. Sometimes, I’m having them schedule it preventively, noting that they can take up to 8 tabs a day and that is expected and can easily be reduced if the loperamide is not working by doing things like dose reducing even just a little bit.