FSI-174

FSI-174 is a **humanized monoclonal antibody** targeting **cKIT** (CD117), a receptor highly expressed on hematopoietic stem cells (HSCs)[8][1]. It inhibits the stem cell growth factor receptor (cKIT), depleting hematopoietic stem and progenitor cells through mechanisms including antibody-dependent cell-mediated cytotoxicity (ADCC) and induction of phagocytosis[8][5]. FSI-174 is primarily developed as part of a novel, **all-antibody conditioning regimen** (especially in combination with magrolimab, an anti-CD47 antibody) to replace chemotherapy or radiation for preparative regimens in stem cell transplantation[3][8]. The therapeutic goal is safer and more targeted conditioning for hematologic malignancies and transplantation, addressing the limitations of conventional approaches[8][7]. Preclinical data has shown that FSI-174 selectively depletes bone marrow HSCs in non-human primate models, particularly when combined with magrolimab, without causing cytopenias or off-target toxicities[8][6]. Clinical development is ongoing for the conditioning of patients with hematologic neoplasms undergoing stem cell transplantation[1][2][3][4]. GS 0174 is a synonym used in trial records.

Other names

FSI-174FSI174FSI 174GS 0174GS0174GS-0174anti-cKIT antibody