Managing CDK4/6 Inhibitor, ADC Toxicity in Metastatic Breast Cancer

In a conversation with CancerNetwork^®, Sarah Donahue, MPH, NP, discussed strategies for managing adverse effects (AEs) associated with different drug classes for patients with metastatic breast cancer, ranging from antibody drug conjugates (ADCs) to CDK4/6 inhibitors.

With respect to ADCs, Donahue, a nurse practitioner at University of California, San Francisco, and member of the Oncology Nursing Society, highlighted common AEs following treatment with trastuzumab deruxtecan (T-DXd; Enhertu) and sacituzumab govitecan-hziy (Trodelvy). In particular, she spoke about the necessity of managing nausea associated with T-DXd by helping patients schedule doses with antiemetic drugs, as well as mitigating fatigue and improving quality of life in the process. For those who are treated with sacituzumab govitecan, Donahue spoke about mitigating abdominal cramping at her infusion center and administering loperamide to help patients manage acute diarrhea.

Donahue also discussed her methods for managing toxicity related to CDK4/6 inhibitors including palbociclib (Ibrance), ribociclib (Kisqali), and abemaciclib (Verzenios). Among patients with hormone receptor (HR)–positive breast cancer, treatment with palbociclib and ribociclib, when given in combination with hormonal therapy, may result in fatigue, hot flashes, and arthralgia. According to Donahue, encouraging patients to exercise often may combat fatigue while mitigating arthralgia associated with an aromatase inhibitor. Moreover, she stated that loperamide may help manage potential diarrhea following treatment with abemaciclib.

Overall, Donahue underscored the importance of keeping patients on treatments with CDK4/6 inhibitors and other treatments by being communicative with them regarding the potential to alleviate AEs. She suggested that such openness may give patients the confidence to ask providers for guidance on how to manage their disease.

“The main thing that I find most helpful for my patients is to explain the potential [adverse] effects, explain that there’s something that we can do about them—that we can intervene. If they reach out to us sooner, we can help them more,” Donahue concluded. “I hope that the providers who are listening to this now can help to empower their patients to reach out and to ask for advice. That’s the best thing that they can do to keep them on these medications longer. They can work well; we can show that in studies. But if we can’t keep [patients] on the medications, then what are we doing?”