In the past, chemotherapy was the go-to treatment for patients with HR+/HER2- breast cancer with visceral metastases, which most commonly involve lung and liver. Dr Adam M. Brufsky, of the University of Pittsburgh School of Medicine, reports that the advent of CDK4/6 inhibitors offers an opportunity for several different courses of action appropriate to subgroups within this population of patients.
Three CDK4/6 inhibitors are FDA approved for clinical practice. Dr Brufsky summarizes results from three studies of CDK4/6 inhibitors — abemaciclib, ribociclib, and palbociclib — where these agents were used as second-line therapy after progression on a nonsteroidal aromatase inhibitor. In combination with fulvestrant, all three offered significant benefits in progression-free survival (PFS) and two in overall survival (OS). Among those who derived survival benefit were patients who had visceral metatases, who constituted 56%, 27% and 60% of the respective studies.
For patients who show progression on CDK4/6 inhibitors, additional treatment can be determined by genomic sequencing. Combination therapy with alpelisib and fulvestrant has been shown to lengthen PFS in patients whose tumors have PIK3 mutations. Patients without PIK3 mutations can be treated with fulvestrant or a combination of fulvestrant and everolimus.
Adam M. Brufsky, MD, PhD, Professor, Department of Medicine, Division of Hematology-Oncology, University of Pittsburgh School of Medicine; Associate Chief, Department of Medicine, Division of Hematology-Oncology, UPMC-Hillman Cancer Center, Pittsburgh, Pennsylvania.
Adam M. Brufsky, MD, PhD, has disclosed the following relevant financial relationships:
Received income in an amount equal to or greater than $250 from: Seattle Genetics; Roche; AstraZeneca; Puma; Daiichi Sankyo.