Dr. Jain on Potential Biomarkers in HR-Positive, HER2-Negative Breast Cancer

Amit Jain, MD, a hematology oncology fellow at The University of Tennessee Health Science Center, discusses the potential role of emerging biomarkers in selecting treatment with CDK7 inhibitors in patients with metastatic hormone receptor (HR)–positive, HER2-negative breast cancer.

In a phase 1/2 trial (NCT03363893) investigating samuraciclib, a CDK7 inhibitor, in combination with fulvestrant (Faslodex) in this patient population, patients with TP53 wild-type disease demonstrated the best responses when compared with patients with TP53 mutations, Jain says. These data show that tumor TP53 status is a possible biomarker for predicting the efficacy of CDK7 inhibitors in patients with advanced HR-positive, HER2-negative breast cancer, Jain explains.

Additionally, this study showed that the absence of liver metastases may predict samuraciclib efficacy, as patients with liver metastases had a median progression-free survival (PFS) of 11.9 weeks compared with a PFS that was not yet reached in patients without liver metastases, Jain notes. Although this was a small study, these findings provide an important basis for future investigation of CDK7 inhibitor efficacy and reliable biomarkers, Jain concludes.