Our Pipeline

We have developed a pipeline of small molecule, oral antagonists of the chemokine receptor CXCR4. We believe that inhibition of the CXCR4 receptor creates the potential to provide therapeutic benefit across a wide variety of diseases, including chronic neutropenic disorders and certain types of cancer. While internally we are solely focused on developing our lead candidate, mavorixafor, for chronic neutropenia indications, we are also pursuing partnership opportunities to further advance our oncology programs.

About Mavorixafor

Our lead product candidate is mavorixafor, a first-in-class, oral, selective small molecule CXCR4 antagonist that inhibits receptor binding by CXCL12, its cognate ligand. Mavorixafor is designed to correct the abnormal signaling caused by the dysfunction of the receptor/ligand interaction and enable mobilization of immune cells, increasing levels of circulating white blood cells, including neutrophils, to improve immune system function.

To date, more than 200 individuals in clinical trials have been dosed with mavorixafor, which has demonstrated a favorable tolerability profile. We are currently conducting multiple clinical trials of mavorixafor: a pivotal, Phase 3 clinical trial in individuals with WHIM syndrome, a rare primary immunodeficiency caused by mutations in the CXCR4 gene, a Phase 1b clinical trial in individuals with a range of chronic neutropenic disorders, and a Phase 1b clinical trial in combination with the BTK inhibitor ibrutinib in individuals with
Waldenström’s macroglobulinemia, a rare type of B-cell lymphoma, caused by mutations to the MYD88 and CXCR4 genes.

Mavorixafor has received multiple special designations from global regulatory authorities: in WHIM syndrome, mavorixafor has been granted Breakthrough Therapy Designation, Fast Track Designation, and Rare Pediatric Designation in the U.S., and Orphan Drug Status in both the U.S. and European Union; mavorixafor has also been granted Orphan Drug Status in the U.S. in Waldenström’s macroglobulinemia, regardless of CXCR4 mutation status. In addition, X4 is eligible to receive a Priority Review Voucher (PRV) as a result of mavorixafor’s Rare Pediatric Designation in the U.S.


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