briquilimab + abatacept

Briquilimab + abatacept is an investigational combination therapy comprising two biologic agents with distinct mechanisms of action. Briquilimab is a humanized, aglycosylated monoclonal antibody that directly inhibits the binding of stem cell factor (SCF) to the KIT receptor (CD117), thereby blocking KIT signaling and inducing mast cell apoptosis. This mechanism targets diseases where mast cells play a pathogenic role[8]. Abatacept is a recombinant fusion protein composed of the extracellular domain of CTLA-4 fused to an IgG1 Fc region; it acts as a selective co-stimulation modulator by binding to CD80 and CD86 on antigen-presenting cells, preventing their interaction with CD28 on T cells and thus inhibiting T-cell activation[2][6][10]. The combination has been studied in clinical trials for use in conditioning regimens prior to hematopoietic cell transplantation (HCT), particularly for patients with sickle cell disease at high risk for morbidity or mortality[1].