New Therapies for HER2-Positive Metastatic Breast Cancer Show Promise, Although Research on Sequencing is Needed

In an interview with Pharmacy Times, Kelly Gaertner, PharmD, an oncology clinical pharmacy specialist with Allegheny Health Network, said that a slew of new treatments for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer offer exciting new possibilities for this patient population, although questions remain about optimal sequencing.

Gaertner will be presenting on the topic on Friday at the Hematology/Oncology Pharmacy Association’s virtual 2021 conference.

Prior to December 2019, Gaertner said the standard first-line therapy for HER2-positive metastatic breast cancer was trastuzumab plus pertuzumab and a taxane. Second-line standard therapy involved ado trastuzumab emtansine. Third and subsequent lines of therapy had no standard regimen, however.

Over the past 18 months, the FDA has approved 4 new regimens for HER2-positive metastatic disease, including trastuzumab deruxtecan; neratinib plus capecitabine; tucatinib, capecitabine, and trastuzumab; and the monoclonal antibody margetuximab. Although questions still remain about the optimal sequencing for these treatments in third and subsequent lines of therapy, Gaertner said the approvals are exciting developments.