EXAGEN INC.

# Exagen Inc.

Exagen designs, develops, and commercializes diagnostic tests for rheumatic, autoimmune, and autoimmune-related diseases under its AVISE brand. The company's primary offering is AVISE CTD, a differential diagnostic test for patients presenting with symptoms consistent with connective tissue diseases and overlapping autoimmune conditions. Additional testing platforms address specific disease areas, including AVISE Lupus for systemic lupus erythematosus (SLE) assessment, AVISE APS for antiphospholipid syndrome diagnosis and management, and AVISE Vasculitis AAV for anti-neutrophil cytoplasmic antibody-associated vasculitis evaluation. The company also offers specialized tests such as AVISE SLE Prognostic, which assesses kidney, brain, and cardiovascular complications; AVISE Anti-CarP, a rheumatoid arthritis prognostic test; and monitoring tests including AVISE SLE Monitor, AVISE MTX, and AVISE HCQ.

The company operates in the clinical laboratory diagnostics market, where it serves healthcare providers treating autoimmune disease patients. Its tests employ proprietary biomarker platforms, including complement biomarker technology (CB-CAPs). Exagen maintains a research collaboration with Allegheny Health Network Research Institute focused on developing T-cell biomarkers. The company operates with 209 full-time employees and is based in Vista, California, serving the United States market. Exagen was incorporated in Delaware in 2002 and is publicly traded on Nasdaq.