Article
作者: Carelli, Jordan ; Zehnder, Luke R ; Hoffman, Robert L ; Tran, Khanh T ; Lee, Nathan ; Niessen, Sherry ; McMillan, Elizabeth ; Xu, Meirong ; Looper, David ; Wilson, Elizabeth ; White, Michael A ; Solowiej, James E ; Ding, Ying ; Weinrich, Scott L ; McTigue, Michele ; Nagata, Asako ; Ferre, Rose Ann ; Ornelas, Martha A ; Salek-Ardakani, Shahram ; Sutton, Scott ; VanArsdale, Todd ; Nguyen, Lisa ; Murray, Brion ; Mu, Xinmeng Jasmine ; Bienkowska, Jadwiga R ; Behenna, Douglas ; Wang, Tim S ; Boras, Britton ; Zhang, Cathy ; Visswanathan, Ravi ; Kephart, Susan E ; Chionis, John ; Almaden, Jonathan ; Huser, Nanni ; Lapek, John ; Costa-Jones, Cinthia ; Liu, Chaoting ; Zhang, Qin ; Miller, Nichol ; Dann, Stephen G ; Freeman-Cook, Kevin ; Kan, Zhengyan ; Eisele, Koleen ; He, You-Ai ; Ninkovic, Sacha ; Wei, Ping ; Zhu, Zhou ; Oderup, Cecilia
The CDK4/6 inhibitor, palbociclib (PAL), significantly improves progression-free survival in HR+/HER2- breast cancer when combined with anti-hormonals. We sought to discover PAL resistance mechanisms in preclinical models and through analysis of clinical transcriptome specimens, which coalesced on induction of MYC oncogene and Cyclin E/CDK2 activity. We propose that targeting the G1 kinases CDK2, CDK4, and CDK6 with a small-molecule overcomes resistance to CDK4/6 inhibition. We describe the pharmacodynamics and efficacy of PF-06873600 (PF3600), a pyridopyrimidine with potent inhibition of CDK2/4/6 activity and efficacy in multiple in vivo tumor models. Together with the clinical analysis, MYC activity predicts (PF3600) efficacy across multiple cell lineages. Finally, we find that CDK2/4/6 inhibition does not compromise tumor-specific immune checkpoint blockade responses in syngeneic models. We anticipate that (PF3600), currently in phase 1 clinical trials, offers a therapeutic option to cancer patients in whom CDK4/6 inhibition is insufficient to alter disease progression.