Yeon Hee Park, MD, PhD, on Metastatic Breast Cancer: Updated Survival Results of the Young-PEARL Study

YoungPEARL study is a prospective randomized phase 2 study to compare palbociclib plus exemestane plus GnRH agonist versus capecitabine for premenopausal HR-positive HER2-negative metastatic breast cancers. Actually, this clinical trial was published and presented in 2019. According to that trial research, palbociclib plus exemestane plus GnRH antagonist showed a superior PFS compared to the capecitabine. Their median PFS was 20.1 months versus capecitabine, 14.4 months. This kind of real big research contributed to expansion of palbociclib plus AI label to include premenopausal population. So now, here we reported updated overall survival research. Data cutoff is February 29th, 2024 with median follow-up duration of 54 months. So we follow up the updated PFS research to show the consistent superior PFS showed in palbociclib arm. Median PFS was 19.5 months versus 14 months of PFS shown in capecitabine arm. Hazard ratio in people was strongly enough to consider it's a big impact in terms of PFS. And now, we show the overall survival research. There is no big difference between the two arm. Palbociclib arm showed the 54.7 months of PFS, and then capecitabine arm showed a remarkable PFS of 57.8 months. They did not show any difference, but it's 54 months of longer follow-up duration. Palbociclib arm showed a pretty consistent, longer overall survival of 54.8 months. So it's a really... Extended overall survival was shown in palbociclib arm. But palbociclib superior PFS did not lead to the overall survival benefit compare capecitabine arm. But capecitabine arm showed... Multivariate analysis showed the post-treatment CDK4/6 inhibitor was identified as a independent favorable factor for overall survival with statistical significance. So maybe post CDK inhibitor treatment contributed to extended overall survival in palbociclib arm.