Article
Author: Forseth, Ry R ; Tallarico, John A ; Magracheva, Anna ; Xu, Lei ; Hainzl, Dominik ; Fazal, Aleem ; Briner, Karin ; Bhang, Hyo-Eun C ; Beckwith, Rohan E J ; Wartchow, Charles A ; Tullai, Jennifer ; Chie-Leon, Barbara ; Ramesh, Radha ; Zécri, Frédéric J ; Jain, Rishi K ; Csibi, Alfredo ; Dranoff, Glenn ; Cobb, Jennifer S ; Wang, Y Karen ; Lu, Hongbo ; Sabatos-Peyton, Catherine A ; Alexander, Dylan ; d'Hennezel, Eva ; Thomsen, Noel M ; Dales, Natalie A ; Fortnam, Bethany Hughes ; Larrow, Jay ; Carbonneau, Seth ; Gu, Yi ; Clifton, Matthew C ; Caro, Roxana García ; Cernijenko, Artiom ; Bradner, James E ; Bonazzi, Simone ; Visser, Michael ; Ma, Xiaolei ; Porter, Jeffery A ; Engelman, Jeffrey A ; Meyer, Matthew J ; Kinyamu-Akunda, Jacqueline ; Shulok, Janine ; Solomon, Jonathan M ; Lu, Darlene ; Antonakos, Brandon ; Ornelas, Elizabeth
Malignant tumors can evade destruction by the immune system by attracting immune-suppressive regulatory T cells (Treg) cells. The IKZF2 (Helios) transcription factor plays a crucial role in maintaining function and stability of Treg cells, and IKZF2 deficiency reduces tumor growth in mice. Here we report the discovery of NVP-DKY709, a selective molecular glue degrader of IKZF2 that spares IKZF1/3. We describe the recruitment-guided medicinal chemistry campaign leading to NVP-DKY709 that redirected the degradation selectivity of cereblon (CRBN) binders from IKZF1 toward IKZF2. Selectivity of NVP-DKY709 for IKZF2 was rationalized by analyzing the DDB1:CRBN:NVP-DKY709:IKZF2(ZF2 or ZF2-3) ternary complex X-ray structures. Exposure to NVP-DKY709 reduced the suppressive activity of human Treg cells and rescued cytokine production in exhausted T-effector cells. In vivo, treatment with NVP-DKY709 delayed tumor growth in mice with a humanized immune system and enhanced immunization responses in cynomolgus monkeys. NVP-DKY709 is being investigated in the clinic as an immune-enhancing agent for cancer immunotherapy.