Bispecific Antibodies for Research: From PD-L1×CD3 T Cell Engagers to Dual-Checkpoint Blockade

Bispecific antibodies — engineered to bind two distinct epitopes simultaneously — have moved from a niche antibody engineering concept to one of the most active areas of drug development, with T cell engagers now approved across multiple hematologic malignancies and dozens more in clinical trials for solid tumors. For researchers, this shift means growing demand for well-characterized bispecific research tools: both reference antibodies that reproduce the binding profile of approved and investigational bispecifics, and recombinant bispecific antibodies for building custom research assays.

This guide introduces abinScience's newly added PD-L1×CD3 bispecific antibodies and surveys the broader bispecific antibody toolkit available for T cell engager research and beyond.

What Makes T Cell Engagers Different

A T cell engaging bispecific antibody (often called a BiTE-format molecule, though BiTE is a specific proprietary format) binds CD3 on the T cell surface with one arm and a tumor-associated antigen with the other—physically bridging a T cell to a tumor cell and triggering T cell activation and cytotoxicity independent of native T cell receptor specificity. This mechanism underlies several approved therapies (blinatumomab and teclistamab) and is now being extended to solid tumor targets, including PD-L1.

New: PD-L1×CD3 Bispecific Recombinant Antibodies

abinScience has added two recombinant anti-PD-L1/B7-H1 & CD3 epsilon bispecific antibodies, clones SAA3042 and SAA3043, to its bispecific research catalog. Both are engineered as recombinant antibodies with defined sequence identity, supporting reproducible use as T cell engager research tools, positive controls for bispecific binding assays, or benchmarking reagents for in-house bispecific candidate development.

The Broader Bispecific Antibody Landscape

Beyond PD-L1×CD3, abinScience's bispecific catalog—spanning 161 products—covers two major categories: reference antibodies that reproduce approved or clinical-stage bispecific therapeutics for benchmarking, and recombinant bispecific antibodies built for specific research applications, including T cell engagers targeting other tumor antigens and dual immune-checkpoint blockade formats.

CD3 T Cell Engager Reference Antibodies

Dual Checkpoint & Dual Pathway Bispecifics

Not all bispecifics engage CD3—a growing category instead targets two disease-relevant pathways simultaneously to achieve deeper pathway blockade than either monospecific antibody alone:

The mouse surrogate CTLA-4×PD-1 bispecifics are particularly useful for preclinical dual-checkpoint blockade studies in syngeneic mouse tumor models, where a single molecule can substitute for combination dosing of two separate checkpoint inhibitors. For the complete set of 161 bispecific antibody products—including additional CD3 engagers, dual-checkpoint, and multispecific reference antibodies—browse the full bispecific antibody catalog →

Choosing Between Reference and Recombinant Bispecific Antibodies