Dr Tarantino on Research in HR+ Breast Cancer

Paolo Tarantino, MD, researcher, the European Institute of Oncology; clinical research fellow, Dana-Farber Cancer Institute, and Yan Leyfman, MD, internal medicine and clinical researcher, Mount Sinai; co-founder, executive director, MedNews Week; executive committee member, Music Beats Cancer, discuss ongoing investigations into the treatment of patients with hormone receptor (HR)–positive breast cancer on OncLive® News Network: On Location at the 2024 ASCO Annual Meeting.

Leyfman begins by stating that breast cancer was one of the major themes at the 2024 ASCO Annual Meeting. He states that there’s an abundance of data and numerous trials to review, including the phase 3 postMONARCH study (NCT05169567).

Tarantino begins by saying that the findings from postMONARCH were highly anticipated as they addressed a critical question: Can oncologists sequence CDK4/6 inhibitors? These drugs, which target the cyclin D-CDK4/6 pathway, have revolutionized the treatment of patients with HR-positive breast cancer, he says. However, different studies have shown varying outcomes regarding the sequencing of 1 CDK4/6 inhibitor after progression on another, Tarantino reports. postMONARCH evaluated abemaciclib (Verzenio) in combination with fulvestrant (Faslodex) in patients with HR-positive disease after progression on CDK4/6 inhibitors. The biggest beneficiaries of this research will undoubtedly be the patients, as these findings expand the treatment options available to achieve long-term positive outcomes in this population, Leyfman expands.

Another significant study making headlines at ASCO was the phase 2 SACI-IO HR+ trial (NCT04448886), Leyfman notes. Tarantino is excited about this randomized study that sought to answer an important scientific question regarding HR-positive breast cancer. Typically, this type of breast cancer is considered “immuno-cold,” meaning it does not respond well to immunotherapy, he explains. The goal of this trial was to determine whether this type of cancer could be made “hot,” or responsive to immunotherapy, using an antibody-drug conjugate. The trial enrolled patients who had received prior endocrine treatment and 0 to 1 prior lines of chemotherapy, testing sacituzumab govitecan-hziy (Trodelvy) with or without pembrolizumab (Keytruda), he concludes.