Our therapies aim to restore healthy immunity. Our grit drives solutions for patients.

It is our firm belief that better outcomes are possible for patients with primary genetic immunodeficiencies and cancer. We strive everyday in our pursuit of new, innovative medicines that are designed to restore healthy immunity to treat disease.

About X4

Based upon the emerging science of immune regulation, our founders realized the potential of targeting CXCR4 as a validated pathway to stimulate healthy immunity in diseases.


X4 is advancing clinical studies with our pipeline of best-in-class, oral small molecule CXCR4-targeted medicines to treat rare primary immunodeficiency diseases and cancer.