Mixed maintenance.

Three trials have evaluated adjuvant CDK 4/6 inhibitors for women with high risk, hormone receptor positive breast cancer. Here, long-term results of the randomized, phase 3 PALLAS trial confirm there was no benefit in 4-year invasive disease free survival when 2 years of adjuvant palblociclib was added to endocrine therapy in nearly 6000 participants (84.2% v 84.5%). While the PENELOPE trial was also recently negative, the monarchE trial found a 3.5% improvement in 3-year iDFS with 2 years of abemaciclib. | Gnant, J Clin Oncol 2021