Discovery and characterization of a selective IKZF2 glue degrader for cancer immunotherapy.

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.
Competing Interests: Declaration of interests All authors are past or current employees of Novartis Institutes for Biomedical Research. Some of the authors have patents related to this work: WO2019038717, 3-(1-oxoisoindolin-2-YL)Piperidine-2-6-Dione derivatives and uses thereof (R.E.J.B., S.B., A.C., A.F., and M.V.); and WO2020128972, Dosing regimen and pharmaceutical combinations comprising 3-(1-oxoisoindolin-2-YL)Piperidine-2-6-Dione derivatives (S.B., E.d’H., G.D., R.R.F., D.H., and J.K.-A.).
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