Multiplexed Bioassay for Checkpoint Inhibitor Autoimmunity

The advent of checkpoint inhibitor (CPI) therapy in human cancer has dramatically changed the landscape of
treatment strategies in recent years. Previously, cancers with largely ineffective therapeutics and a poor
prognosis, such as melanoma, have experienced significant advances of patients able to extend survival
and/or progression free disease. Within the tumor microenvironment, a number of immunosuppressive
molecules are overexpressed, including CTLA-4, PD-1 and its ligand PD-L1. Simply put, inhibiting these
immunosuppressive pathways causes the reactivation of ‘exhausted’ cytotoxic and helper T cells and
subsequent attack of the tumor. However, patients treated with CPIs have experienced a variety of untoward
side effects of immune mediated adverse events (irAEs), many leading to significant morbidity and
uncertainties in balancing the management of both the autoimmunity and the cancer. These adverse events
(of grades 1-5) include colitis, pneumonitis, neuropathies, endocrinopathies, nephritis, dermatitis, and arthritis.
It is reported that upwards of 80% of CPI treated patient will experience some form of irAE. As the numbers of
patients treated with CPIs increases, coupled with the use of CPIs in combination therapies as well as the
development of new generations of CPIs, the treatment of irAEs will complicate medical care in these patients.
The simple goal of the present proposal is to develop a Luminex based bioassay of the key protein biomarkers
to which CPI patients elicit autoantibodies both prior to, and as the appearance of autoimmune syndromes
arise. A multiplexed Luminex system can detect as many as 50 biomarkers and be simply modified as new
biomarkers may emerge in the future of CPI therapy. The project is strengthened by a PI who directs a CLIA
certified diagnostic laboratory in the Department of Medicine at Yale University with close ties to the Section of
Medical Oncology and with an existing serum library collection of both patients treated with CPIs and of
patients with spontaneous autoimmune disease. Phase I studies will develop and perform early specificity
studies with the panel of biomarkers while phase II studies will be expanded to include a screening of larger
cohorts of patients on specific CPI types as well as a robust, sensitive and specific bioassay system.This project will develop a Luminex bead based bioassay system to assess the key targets of immune related
adverse events (irAEs) in cancer patients treated with checkpoint inhibitors (CPIs). The scope of the 12
month project will be to acquire the protein biomarkers, development of the multiplex bead system, and
assess standardized control sera, both commercially available and analytes from the College of American
Pathology (CAP), as well as a cohort of CPI treated cancer patients.