It does not appear that having a PIK3CA mutation inhibits the activity of [cyclin-dependent kinase (CDK)]4/6 inhibitors, which many of us were concerned about. This is a completely new finding.
—Ian E. Krop, MD, PhD
Ian E. Krop, MD, PhD, of Dana-Farber Cancer Institute, Boston, commented on the findings by Ma et al in an interview with The ASCO Post, calling the study “very elegantly designed.”
“The study provides three important pieces of information. One, it suggests that palbociclib can add to the benefit of aromatase inhibitors in the neoadjuvant setting, which we didn’t know before,” he said.
“Two, it does not appear that having a PIK3CA mutation inhibits the activity of [cyclin-dependent kinase (CDK)]4/6 inhibitors, which many of us were concerned about. This is a completely new finding,” he noted.
“Lastly, there is the inadvertent finding that when they stopped the drugs to allow patients to go to surgery, Ki67 rebounded. This suggests we may need to keep patients on palbociclib longer,” Dr. Krop continued.
He indicated that the adjuvant trials of palbociclib, such as the PALLAS study, are evaluating 2 years of treatment with the drug. “I think these data support that approach,” he concluded. ■
Disclosure: Dr. Krop reported no potential conflicts of interest.
The cyclin-dependent kinase (CDK) 4/6 inhibitor palbociclib (Ibrance) enhanced cell-cycle control over that achieved with anastrozole alone in a study that evaluated the drugs’ ability to induce complete cell-cycle arrest in tumor cells and to produce clinical responses, as neoadjuvant therapy for ...