CTLA-4-ETB-A

**CTLA-4-ETB-A** is a preclinical CTLA-4-targeted engineered toxin body developed by Molecular Templates as part of its ETB oncology platform. It is an investigational biparatopic CTLA-4-directed biologic that binds CTLA-4-expressing cells, particularly regulatory T cells in the tumor microenvironment, and delivers a de-immunized Shiga-like toxin A payload intracellularly to inactivate ribosomes, shut down protein synthesis, and induce apoptotic cell death. Available preclinical reports describe CTLA-4-ETB-A as a lead candidate that directly kills CTLA-4-positive cells and depletes ex vivo expanded Tregs, supporting its intended use as an immuno-oncology agent designed to enhance antitumor T-cell immunity through selective Treg depletion rather than conventional sustained checkpoint blockade.