Preferred Label : Maplirpacept;
NCIt synonyms : SIRPa-IgG4 Fc; SIRPa-IgG4 Fc TTI-622; SIRPa-IgG4-Fc Fusion Protein TTI-622;
NCIt definition : A soluble recombinant antibody-like fusion protein composed of the N-terminal CD47
binding domain of human signal-regulatory protein alpha (SIRPa; CD172a) linked to
an Fc domain derived from human immunoglobulin G subtype 4 (IgG4), with potential
immune checkpoint inhibitory, phagocytosis-inducing and antineoplastic activities.
Upon administration, maplirpacept selectively targets and binds to CD47 expressed
on tumor cells and blocks the interaction of CD47 with endogenous SIRPa, a cell surface
protein expressed on macrophages. This prevents CD47/SIRPa-mediated signaling and
abrogates the CD47/SIRPa-mediated inhibition of macrophage activation. This induces
pro-phagocytic signaling resulting from the binding of calreticulin (CRT), which is
specifically expressed on the surface of tumor cells, to low-density lipoprotein (LDL)
receptor-related protein-1 (LRP-1) expressed on macrophages, and results in macrophage
activation and the specific phagocytosis of tumor cells. CD47, also called integrin-associated
protein (IAP), is a tumor-associated antigen (TAA) expressed on normal, healthy hematopoietic
stem cells (HSC) and overexpressed on the surface of a variety of cancer cells. Expression
of CD47, and its interaction with SIRPa, leads to the inhibition of macrophage activation
and protects tumor cells from phagocytosis, thereby allowing these cells to proliferate
and survive.;
UNII : 44D51T6SZH;
CAS number : 2631667-06-4;
Molecule name : TTI 622; TTI-622; PF-07901801; PF 07901801;
NCI Metathesaurus CUI : CL552621;
Origin ID : C150756;
UMLS CUI : C5783369;
Semantic type(s)
- concept_is_in_subset
- has_target
