Discovery of a Locally and Orally Active CXCL12 Neutraligand (LIT-927) with Anti-inflammatory Effect in a Murine Model of Allergic Airway Hypereosinophilia

Abstract

We previously reported Chalcone-4 (1) that binds the chemokine CXCL12, not its cognate receptors CXCR4 or CXCR7, and neutralizes its biological activity. However, this neutraligand suffers from limitations such as poor chemical stability, solubility, and oral activity. Herein, we report on the discovery of pyrimidinone 57 (LIT-927), a novel neutraligand of CXCL12 which displays a higher solubility than 1 and is no longer a Michael acceptor. While both 1 and 57 reduce eosinophil recruitment in a murine model of allergic airway hypereosinophilia, 57 is the only one to display inhibitory activity following oral administration. Thereby, we here describe 57 as the first orally active CXCL12 neutraligand with anti-inflammatory properties. Combined with a high binding selectivity for CXCL12 over other chemokines, 57 represents a powerful pharmacological tool to investigate CXCL12 physiology in vivo and to explore the activity of chemokine neutralization in inflammatory and related diseases.

Neutralization of CXCL12 attenuates established pulmonary hypertension in rats

“…This present translational research investigated the activity of two CXCL12 neutraligands against established PH in two complementary animal models of severe PH [18][19][20] . Hence, we firstly conducted immunofluorescence and confocal analyses of CXCL12, CXCR4, and CXCR7 protein levels in lungs from patients with iPAH and from rats with established PH.…”

“…Consistent with these in vivo observations, our in vitro findings obtained with primary cultures of human PA-SMCs and pulmonary pericytes indicate that CXCL12 neutralization, in contrast to CXCR4 antagonism with AMD3100, substantially inhibits cell migration in a concentration-dependent manner. Because accumulation of both PA-SMCs, pulmonary pericytes and inflammatory cells in walls of distal pulmonary arteries increases substantially during disease progression in PAH 7,9,24,25,33 , potent and selective inhibitors of the CXCL12/CXCR4/CXCR7 axis could open new therapeutic options in PAH, especially neutraligands which prevent binding of CXCL12 to the receptors CXCR4 and CXCR7 19,20 .…”

“…These neutraligands are, indeed, small selective molecules that can rapidly neutralize CXCL12 by direct binding and thus prevent CXCL12 from activating its CXCR4 and CXCR7 receptors [18][19][20] . In addition to reduce migration of human PA-SMCs and pulmonary pericytes, chalcone 4 and LIT-927 attenuate the proliferation of human PA-SMCs in vitro (Supplemental Fig.…”

“…Because CXCR7, which binds to the ligand CXCL12 with higher affinity than CXCR4, also contributes to cell migration and homing induced by CXCL12, the notion that chemokine blockade could be an interesting strategy to be used as an alternative to conventional receptor blockade has emerged. In this context, we have recently identified chemokine-neutralizing molecules (neutraligands) that prevent CXCL12 from acting on its two main receptors CXCR4 and CXCR7, namely chalcone 4 17,18 and the recently reported LIT-927, which is the first locally and orally active CXCL12 neutraligand with anti-inflammatory effect in a murine model of allergic airway hypereosinophilia 19 . However, the activity of CXCL12 neutraligands has not yet been studied in PAH.…”

Modulators of CXCR4 and CXCR7/ACKR3 Function

“…Recently, modifications of the CXCL12 neutraligand 2 led to a discovery of a novel non-Michael acceptor with antiinflammatory effect, LIT-927 ( Fig. 4), with better solubility (Regenass et al, 2018).…”