Quantitative Cell-based Bioassays for Individual and Combination Immune Checkpoint Immunotherapy Targets

The human immune system is comprised of a complex network of immune checkpoint receptors that are promising new immunotherapy targets for the treatment of a variety of diseases including cancer and autoimmune-mediated disorders.

Current methods used to measure the activity of antibody and other biologics drugs designed to target immune checkpoint receptors rely on primary human cells and measurement of functional endpoints such as cell proliferation, cell surface marker expression, and cytokine production. These assays are laborious and highly variable due to their reliance on donor primary cells, complex assay protocols, and unqualified assay reagents. As a result, these assays are difficult to establish in quality-controlled drug development settings.

To overcome these challenges, we developed a suite of cell-based bioluminescent reporter bioassays for individual and combination immune checkpoint immunotherapy targets including:

• PD-1 (PD-L1 or PD-L2), CTLA-4, LAG-3, TIGIT, PD-1+TIGIT

• GITR, 4-1BB, CD40, OX40

These mechanism of action (MOA)-based bioassays are available in “thaw-and-use” format and demonstrate high specificity, sensitivity, and reproducibility. The bioassays are qualified according to ICH guidelines and demonstrate the performance required for use in antibody screening, potency testing, and stability studies.