CC-122 Is a Novel Pleiotropic Pathway Modifier with Potent in Vitro Immunomodulatory and Anti-Angiogenic Properties and in Vivo Anti-Tumor Activity in Hematological Cancers.
Authors: Gandhi Anita K , Mendy Derek , Parton Anastasia , Wu Lei , Kosek Jolanta , Zhang Ling-Hua , Capone Lori , Lopez-Girona Antonia , Schafer Peter H , Chopra Rajesh 
Published: October 2019

Abstract
Abstract 2963

Background:
The immunomodulatory agents thalidomide (THAL), lenalidomide (LEN), and pomalidomide (POM) have significant activity in a wide range of hematologic cancers. THAL is primarily a potent anti-angiogenic agent with minimal immunomodulatory activity. LEN and POM both demonstrate significant immunomodulatory activity. Additionally, POM displays anti-myeloma activity in patients with LEN-resistant multiple myeloma (MM). Recently, modulation of cereblon (CRBN)-bound E3 ubiquitin ligase complexes has been implicated in the mechanisms of action of THAL, LEN, and POM. This has enabled rational development of a next generation of compounds. CC-122 is a non-phthalimide analog of the immunomodulatory drugs and a first in class PPM™ pleiotropic pathway modulator that binds the CRBN-DDB1-Cul4-Roc1 E3 ubiquitin ligase complex. This study investigated the anti-proliferative, immunomodulatory, and anti-angiogenic activity of CC-122 in MM and lymphoma cells.

Results:
CC-122 inhibited proliferation of H929 MM cells in a CRBN-dependent and dose-dependent manner (IC50 = 43 nM). CC-122 induced cell cycle arrest at G0/G1 stage, which was associated with reduced retinoblastoma protein phosphorylation, and increased CDK inhibitor p27 protein expression. CC-122 also inhibited the growth of LEN-resistant H929 cells, although the proliferation IC50 for CC-122 was relatively higher in LEN-resistant cells vs H929 control cells (Table). CC-122 has significant anti-myeloma activity, and has greater activity in LEN-resistant H929 cells vs LEN and POM. Compared with LEN, CC-122 had a greater anti-proliferative effect in diffuse-large B-cell lymphoma (DLBCL). Furthermore, CC-122 had greater anti-proliferative effects in ABC- and PBML-subtypes compared with GCB subtype lines. In ABC-subtype U2932 and OCI-Ly10-DLBCL cell lines, 10 μM CC-122 treatment significantly inhibited DNA-binding of NF-κB p65 (P < .001), p50 subunits (P < .05), and IRF4 in a CRBN-dependent manner. In vivo anticancer activity of CC-122 was demonstrated in xenograft models of human lymphoma and MM.
CC-122 exhibits potent immunomodulatory activity in whole blood, T, and natural killer (NK) cells. Additionally, CC-122 enhanced the anti-CD3 mAb-stimulated T-cell production of IL-5, IL-13, GM-CSF, IFN-γ, RANTES, and TNF-α. The immunomodulatory activity of CC-122 was 10-fold more potent vs LEN.
We investigated the anti-angiogenic properties of CC-122. In a human umbilical artery sprout outgrowth assay, CC-122 inhibited new vessel growth as well as endothelial cell migration and invasion. It also inhibited endothelial cell sprout formation and migration in a growth factor-induced endothelial cell migration and invasion assay. CC-122 has significantly greater anti-angiogenic activity compared with the LEN and POM in human angiogenesis assays (Table). In contrast, it has less of an anti-platelet effect as measured by megakaryocyte proliferation vs LEN and POM.
CRBN binding competition assays were conducted with THAL-binding beads. As demonstrated by the higher IC50 concentration, CC-122 has less potency with regard to CRBN binding compared with LEN or POM.

Conclusion:
Together, these data demonstrate that the first-in-class PPM™ CC-122 has anti-proliferative, immunomodulatory, and anti-angiogenic properties that may have clinical significance in the treatment of advanced refractory lymphoproliferative disorders and is currently in Phase I studies. Furthermore the data suggest that the potency of binding to CRBN per se does not explain the broad pleiotropic activity of CC-122.

Disclosures:
Gandhi: Celgene Corp: Employment, Equity Ownership. Mendy:Celgene Corp.: Employment, Equity Ownership. Parton:Celgene Corp: Employment, Equity Ownership. Wu:Celgene Corp: Employment, Equity Ownership. Kosek:Celgene Corp: Employment, Equity Ownership. Zhang:Celgene Corp: Employment, Equity Ownership. Capone:Celgene Corp: Employment, Equity Ownership. Lopez-Girona:Celgene Corp: Employment, Equity Ownership. Schafer:Celgene: Employment, Equity Ownership. Chopra:Celgene Corp: Employment, Equity Ownership.