FcRH5 (FCRL5)

aka FcRH5, FCRH5, IRTA2, CD307e, Fc receptor-like 5

FcRH5 is a surface protein found almost only on B cells and myeloma plasma cells, which makes it a target for T-cell engaging antibodies in multiple myeloma.

FCRL5 encodes Fc receptor-like 5, a B-lineage surface receptor expressed on mature B cells and retained on plasma cells; on myeloma cells expression is near-universal and higher than on normal counterparts, in part through 1q21 gain where the gene sits. Cevostamab, a FcRH5 x CD3 bispecific antibody, is in late-stage trials for relapsed and refractory multiple myeloma; no approval names the antigen yet.

FcRH5 (FCRL5): what it is and how drugs act on it · animated schematic, not to scale

Target · the protein and the cell it sits on
Drug · antibody, small molecule, cell or radioligand
Effect · signal, damage or kill

In plain words · FcRH5 is a surface protein found almost only on B cells and myeloma plasma cells, which makes it a target for T-cell engaging antibodies in multiple myeloma.

1 · What it is
FcRH5 is a surface protein found almost only on B cells and myeloma plasma cells, which makes it a target for T-cell engaging antibodies in multiple myeloma.
2 · What goes wrong in cancer
A type I transmembrane protein with immunoglobulin-like domains that modulates B-cell receptor signalling; its restricted lineage expression, like BCMA and GPRC5D, is what makes it a T-cell redirection target.
3 · How drugs use it
No product in this corpus aims at FcRH5 (FCRL5) yet. Because it sits on the outside of the cell, it can be reached from the bloodstream: antibodies flag the cell, ADCs deliver a toxin, radioligands deliver radiation, and CAR-T or bispecifics bring a T cell.

Full dossier: hotspots, trials, resistance, assays, models, open questions →

External identifiers

FCRL5HGNCEnsemblUniProtAlphaFold DBChEMBLOpen TargetsCIViCOncoKBCOSMICcBioPortalDepMapHuman Protein AtlasNCBI GeneOMIM

Readouts and scores

All readouts →

What a pathology or genomic report can say about this target, each with the thresholds approvals use.

IHC scoreno approval threshold
FcRH5 expression

Biology

A type I transmembrane protein with immunoglobulin-like domains that modulates B-cell receptor signalling; its restricted lineage expression, like BCMA and GPRC5D, is what makes it a T-cell redirection target.