Joseph A. Sparano, MD, Professor of Medicine and Women’s Health at the Albert Einstein College of Medicine, New York, was the formal discussant of the study and commented, “These findings confirm the strong signal observed in the phase II PALOMA1 trial, and there were no subgroups that did not derive benefit, with the possible exception of patients who had a short disease-free interval.”

He offered that CDK4/6 inhibitors, a number of which are in development (including ribociclib and abemaciclib), represent an important treatment advance in estrogen receptor–positive metastatic breast cancer. “This represents an entirely new treatment modality,” he said. He also described several large trials in various settings that will further elucidate the role of palbociclib (Ibrance) in this disease.

Adding commentary at the press briefing was Don Dizon, MD, designated ASCO expert and Clinical Co-Director of Gynecologic Oncology at Massachusetts General Hospital, Boston, who offered, “These results are incredibly important for hormone receptor–positive advanced or metastatic breast cancer patients. They present a new option for progressive disease. We now await the follow-up for overall survival and quality-of-life data.” ■

Disclosure: Drs. Sparano and Dizon reported no potential conflicts of interest.