IL21120033 (iLeadBMS)

IL21120033 is a first-in-class small molecule agonist and positive allosteric modulator (Ago-PAM) of the atypical chemokine receptor 3 (ACKR3, also known as CXCR7). Developed by iLeadBMS, a spin-off of IlDong Pharmaceutical, the compound features a dual mechanism of action: it directly activates ACKR3 and enhances the binding affinity of the endogenous ligand CXCL12. This promotes the clearance of CXCL12, a chemokine central to chronic inflammation and fibrotic processes. IL21120033 is being investigated for the treatment of various autoimmune and fibrotic conditions, including idiopathic pulmonary fibrosis (IPF), rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. It has received FDA Orphan Drug Designation for IPF and is currently in preclinical development, with an IND filing anticipated in 2027.