TAG-binding receptor (on ARC-T cells) (ARC receptor)

The TAG-binding receptor is the central component of the Antigen Receptor Complex T-cell (ARC-T) platform, a modular approach to adoptive cell therapy developed by Arcellx. Unlike standard CAR-T cells, which are constitutively active against a single antigen, ARC-T cells express a universal TAG-binding receptor that remains inactive until a soluble adapter protein, known as a sparX (soluble protein antigen-receptor X-linker), is administered. The sparX protein contains a Targetable Antigen-binding Group (TAG) that is specifically recognized by the receptor on the ARC-T cell, as well as a binding domain for a specific tumor antigen. This dual-binding mechanism allows for precise control over T-cell activity through sparX dosing and the ability to target multiple antigens by using different sparX proteins with the same ARC-T cell population. This technology aims to enhance the safety profile of T-cell therapies by providing a controllable activation mechanism and to overcome tumor heterogeneity in diseases like multiple myeloma and acute myeloid leukemia.

Other names

Antigen Receptor Complex receptorUniversal CARsparX-binding receptorTAG-binding domainTargetable Antigen-binding Group receptor

The TAG-binding receptor on ARC-T cells binds to a specific TAG (Targetable Antigen-binding Group) on a soluble sparX protein. The sparX protein simultaneously binds to a tumor-associated antigen, creating a bridge that activates the ARC-T cell to kill the target tumor cell.