EEDi-5285: An Exceptionally Potent, Efficacious, and Orally Active Small-Molecule Inhibitor of Embryonic Ectoderm Development

Abstract

Inhibition of embryonic ectoderm development (EED) is a new cancer therapeutic strategy. Herein, we report our discovery of EEDi-5285 as an exceptionally potent, efficacious, and orally active EED inhibitor. EEDi-5285 binds to the EED protein with an IC 50 value of 0.2 nM and inhibits cell growth with IC 50 values of 20 pM and 0.5 nM in the Pfeiffer and KARPAS422 lymphoma cell lines, respectively, carrying an EZH2 mutation. EEDi-5285 is approximately 100 times more potent than EED226 in binding to EED and >300 times more potent than EED226 in inhibition of cell growth in the KARPAS422 cell line. EEDi-5285 has excellent pharmacokinetics and achieves complete and durable tumor regression in the KARPAS422 xenograft model in mice with oral administration. The cocrystal structure of EEDi-5285 in a complex with EED defines the precise structural basis for their high binding affinity. EEDi-5285 is the most potent and efficacious EED inhibitor reported to date.

Targeting key proteins involved in transcriptional regulation for cancer therapy: Current strategies and future prospective

“…149 Several other EED inhibitors have shown great promise and been selected as candidates for further preclinical studies, such as EED226, BR-001, A-395, EEDi-5273, EEDi-5285, and LG1980. 140,[150][151][152][153][154][155][156] Among the PRMT inhibitors, GSK3326595 (EPZ015938) as the first-in-class PRMT5 inhibitor has firstly entered clinical trials for advanced solid tumors (Table 2, Figure 4). 157 Other inhibitors, such as PRMT5 inhibitors JNJ-64619178 and PF-06939999, and PRMT1 inhibitor GSK3368715, have already entered clinical trials (Table 2, Figure 4).…”

“…Another compound FTX‐6058 has recently entered Phase I clinical trials for treating sickle cell disease 149 . Several other EED inhibitors have shown great promise and been selected as candidates for further preclinical studies, such as EED226, BR‐001, A‐395, EEDi‐5273, EEDi‐5285, and LG1980 140,150–156 . Among the PRMT inhibitors, GSK3326595 (EPZ015938) as the first‐in‐class PRMT5 inhibitor has firstly entered clinical trials for advanced solid tumors (Table 2, Figure 4).…”

Polycomb Repressive Complex 2 Modulation through the Development of EZH2–EED Interaction Inhibitors and EED Binders

“…A multidisciplinary team from the University of Michigan and Ascentage Pharma began a structure-guided discovery program of EED binders arising from a precursor of 35 , which in the end resulted in exceptionally potent, efficacious, and orally active compounds EEDi-5285 ( 39d ) and EEDi-1056 ( 39f ). 85 Possessing a good antitumor activity in EZH2 mutant lymphoma models as well as in clones resistant to SAM-dependent EZH2 inhibitors, 35 represented a compelling core structure for further optimization. The structure-based campaign started from the previously reported inhibitor 26 (see Figure 11 ), which exhibited moderate competitive activity against EED–H3K27me3 binding in AlphaScreen assay (IC 50 = 0.115 μM) and reasonable anticancer activity in KARPAS422 lymphoma cells (IC 50 = 2.6 μM).…”

“…The structure-based campaign started from the previously reported inhibitor 26 (see Figure 11 ), which exhibited moderate competitive activity against EED–H3K27me3 binding in AlphaScreen assay (IC 50 = 0.115 μM) and reasonable anticancer activity in KARPAS422 lymphoma cells (IC 50 = 2.6 μM). 85 Since the binding affinity to EED strongly depends on π–π stacking interactions with the electron-rich Tyr148/Tyr365 pair in the aromatic cage, the authors initially introduced small electron-withdrawing groups (EWGs; 36a , b ) on the imidazo[1,5- c ]pyrimidine core of 26 . The methylamide-bearing 36b was determined to have biochemical potency comparable to 26 , whereas the ethyl ester derivative 36a was twice as potent (IC 50 = 0.059 μM).…”

“…Second, the phenyl extension was replaced with a variably decorated pyridine-3-yl ring to improve the solubility and simultaneously maintain favorable edge-to-face contacts with Phe97 ( 39b – f ). Because the previously developed binder 35 established hydrophobic interactions with the external surface of EED, the pyridine-3-yl ring and the C8 position of the central scaffold (structures not shown, for further details see ref ( 85 )) were decorated with mostly aliphatic moieties. Among these, the derivative endowed with a 4′-cyclopropyl group, 39d , showed sub-nanomolar activity both on isolated EED (IC 50 = 0.0002 μM) and in cell growth inhibition studies on KARPAS422 and Pfeiffer cells (IC 50 = 0.0005 μM and 20 pM, respectively), thus being endorsed as the best candidate for further biological studies.…”