Automated blood sampling in canine telemetry model: Enhanced assessment of immune liabilities

This manuscript presents a successful integration of multi-timepoint biomarker blood sampling (e.g., cytokines) in a conscious dog cardiovascular study using automated blood sampling via vascular access ports in telemetry instrumented dogs. In addition to determining plasma exposure of the test compound, the assessment of biomarkers of interest allows for more comprehensive preclinical evaluation on a traditional conscious dog cardiovascular (CV) telemetry study especially for immunology and immune-oncology molecules. This model system provides a rapid and efficient means to quickly gain understanding of potential effects on key cardiovascular parameters in large species that are commonly used for preclinical safety evaluations while collecting multiple blood samples for drug and cytokine analysis.

Male beagle dogs were chronically implanted with telemetry devices (PhysioTel™ model D70-PCTP) and vascular access ports (SPMID-GRIDAC-5NC). BASi Culex-L automated blood sampling (ABS) (Bioanalytical Systems, Inc) system was used to collect blood samples at multiple time points for cytokine analysis. Four beagles received low-dose lipopolysaccharide solution (LPS) (0.1 and 0.5 μg/mL). The following cytokines were measured by Milliplex® map Canine Cytokine Magnetic Bead Panel: Interleukin (IL) 2, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, TNF-α, MCP-1, KC-like, GM-CSF, IFN gamma, and IP10.

Low dose LPS administration induced a pronounced dose-dependent, transient release of key inflammatory cytokines (IL-2, IL-6, IL-10, TNF-α, MCP-1, and KC-like). Cytokine responses were similar to other canine and human endotoxin models. LPS administration led to an increase in body temperature, heart rate, and mean arterial pressure, as well as a decrease in QTcV interval.

Successful incorporation of cytokine analysis in telemetry instrumented dogs with vascular access ports allows for translational PK/PD modeling of both efficacy and safety of compounds in the immunology as well as the immune-oncology therapeutic areas designed to modulate the immune system. Remote collection of blood samples simultaneously with CV endpoints is a significant enhancement for assessment of biomarkers that are sensitive to animal handling and excitement associated with room disturbances which are obligatory with manual blood collection. Furthermore, implementing this approach has also refined our animal welfare procedure by reducing the handling during a study and thereby reducing stress (positive refinement 3R impact).