New Breast Cancer Agents Put Focus on Adverse Events, Adherence

The landscape for breast cancer has changed drastically since 2010, with improvement seen in all types of breast cancer.

Historically, human epidermal growth factor receptor 2 (HER2) overexpression was associated with a poor prognosis and an increased risk of recurrent disease, but the recent approvals of 2 oral agents for HER2-positive (HER2+) breast cancer made headlines at national oncology meetings and are improving outcomes for patients.

Tucatinib (Tukysa) is an oral agent studied in combination with trastuzumab (Herceptin) and capecitabine (Xeloda) for metastatic HER2+ breast cancer, including disease with brain metastasis. The research arm with tucatinib decreased the risk of central nervous system progression or death by 68% in patients with brain metastases, compared with the placebo arm.¹

When administering any new agent, oncology nurses must focus on adverse event management and medication adherence with their patients. Patient education should include treating diarrhea, rash, blisters, nausea, fatigue, and increased liver function. Tucatinib is given twice a day for 21 days with or without food. A challenge for patients is the dosing of capecitabine, which is taken twice daily for 14 days within 30 minutes of food when taken with tucatinib.1 Patients will need verbal, written, and other tools (apps, calendars) to ensure proper dosage of these medications.

A second exciting agent is neratinib (Nerlynx), approved for patients who have completed a course of trastuzumab-based therapy after surgery and chemotherapy. It is used as a single agent in the adjuvant setting.²

Neratinib in the extended adjuvant setting is given for 1 year to further reduce the risk of breast cancer recurrence.2 When starting neratinib in the extended adjuvant setting, use a dose titration to assist with diarrhea management.

Fortunately, neratinib crosses the blood-brain barrier and has an indication in combination with capecitabine for the treatment for patients with advanced or metastatic HER2+ breast cancer who have received 2 or more prior HER2-based regimens. In the metastatic setting, neratinib and capecitabine are administered continuously with no breaks throughout the 21-day cycle treatment cycle. This indication for neratinib is in the adjuvant setting where it is given for 1 year to further reduce the risk of recurrence. Patient education should also include oral adherence.

Oncology nurses move with the changing landscape while also providing excellent care to their patients. Thank them for taking on the new challenges and helping patients every day.

References

• Seattle Genetics announces U.S. FDA approval of Tukysa (tucatinib) for people with advanced unresectable or metastatic HER2-positive breast cancer. News release. Seattle Genetics, Inc; April 17, 2020. Accessed October 29, 2020. https://bit.ly/2xtQeBe
• Puma Biotechnology Receives U.S. FDA Approval of Supplemental New Drug Application for Neratinib to Treat HER2-Positive Metastatic Breast Cancer [news release]: Los Angeles, CA. Puma Biotechnology. Published February 27, 2019. https://bwnews.pr/2I02Xx8. Accessed October 29, 2020.