Practice Update: Oncology

MBCC 2017 19

Lightning rounds at the 34th Annual Miami Breast Conference

T he 34th Annual Miami Breast Conference took place form March 9–12 in Miami Beach. It ended on Sunday March 12th with the “Lightning rounds” providing an overview of the conference. The take home messages for metastatic breast cancer were: Brainmetastasis • In patients with brain metastasis whole brain radiation should be avoided. • If the only site of progression is the brain, patients should receive local therapy and systemic therapy should not be changed. HER2+ breast cancer • The demographics of patients with metastatic HER2+ breast cancer has changed. Higher proportion are de novo meta- static and hormone receptor positive. • The first line treatment for metastatic HER2+ breast cancer is the combination of a Taxane with Trastuzumab and Per- tuzumab. The second line is TDM-1 and many options are available for third line. Hormone receptor positive breast cancer • First line therapy for hormone receptor positive metastatic breast cancer has changed. Targeted combinations are superior to their monotherapy comparators. • Novel agents in the treatment of hormone receptor positive breast cancer include mTOR inhibitors (everolimus), CDK inhibitors (palbociclib, ribociclib, abemaciclib) and PI3K inhibitors (buparlisib, taselisib). • CDK4/6 inhibitors are here to stay. Palbociclib is approved for first and second line treatment in combination with letrozole or fulvestrant and Ribociclib will likely be approved this year in combination with letrozole. Triple negative breast cancer • PARP inhibitors will be an option for patients with BRCA1 or BRCA2 germline mutations. • Olaparib met its primary endpoint in the phase III trial in BRCA-mutated metastatic breast cancer. Immunotherapy • Recent advances have been made in immunotherapy for metastatic breast cancer. Combination strategies are needed to enhance the immune infiltrate and their efficacy. Androgen receptor • Based on the encouraging phase II data, studies targeting the androgen receptor are ongoing in both estrogen receptor positive and negative breast cancer. Diagnostics • Assays with circulating tumor cells and circulating tumor DNA are not ready for prime time and routine use. • Combination of biomarkers are critical to future studies.

The MONALEESA-2 was a phase III clinical trial that randomized 668 postmenopausal women with hormone receptor positive, HER2-negative recurrent or metastatic breast cancer who had not received previous systemic therapy for advanced disease to ribo- ciclib in combination with letrozole versus ribociclib plus placebo. The progression free survival was significantly longer in the ribo- ciclib group with a statistical significant hazard ratio of 0.56. With this results probably ribociclib will we approve this year. Finally, MONARCH 1, a phase 2 single-arm study showed that the selective CDK4 and CDK6 inhibitor abemaciclib used as a sin- gle agent induced objective tumor responses as monotherapy in patients with refractory hormone receptor-positive breast cancer that have failed multiple prior therapies. Even though this study did not meet the predefined objective response rate, 42% of women had clinical benefit. Data has also shown that abemaciclib crosses the blood-brain barrier. The toxicity profile of this agents differs in that palbociclib and ribociclib cause more neutropenia and that abemaciclib causes more abdominal pain and diarrhea. We need to refer patients to clinical trials to learn how to use them and which patient popula- tion will benefit from these agents.

PracticeUpdate Editorial Team

PracticeUpdate Editorial Team

VOL. 1 • NO. 1 • 2017