New Biomarker Available to Offer Insight into Thrombosis for Lupus Sufferers

Lupus Patients with Elevated PC4d Levels Have Significantly Increased Occurrence of Thrombosis

SAN DIEGO, CA & ALBUQUERQUE, NM, April 24, 2019 (GLOBE NEWSWIRE) — Exagen Inc., a leader in helping rheumatologist and their patients in the diagnosis, prognosis, and management of chronic autoimmune diseases, today announced new data that suggests a useful role for their patented biomarker, PC4d in helping physicians address thrombosis in lupus patients,one of the most lethal side effects of the condition.

The data, published in a recent issue of Lupus Science & Medicine, suggest that platelet-bound C4d (PC4d) provides additional insight into a patient’s risk of thrombosis, above and beyond the biomarkers traditionally used.

According to Dr. Michelle Petri, Professor of Medicine at the Johns Hopkins University School of Medicine and Director of the Hopkins Lupus Cohort who authored the paper “We know that SLE patients with antiphospholipid antibodies–particularly the lupus anticoagulant–are at increased risk of thrombosis, but our ability to predict who is at highest risk is woefully inadequate. The Hopkins Thrombosis Risk Score, developed in collaboration with Exagen, has included the multifactorial nature of the risk, particularly the involvement of 2 other pathways: low complement; and complement split products bound to platelets (an assay initially developed by Drs Joe Ahearn and Sue Manzi). We recognize that this risk score requires prospective and external validation.”

The biomarker PC4d is part of the broader group of blood tests called cell-bound complement activation products or CB-CAPs. These patented assays,including EC4d, BC4d, & PC4d, are stable biomarkers of complement activation. Measuring deposits resulting from activation of the complement system offers additional insight about the extent to which lupus and the complement system are active in the circulation of an individual patient. Exagen is the exclusive provider of AVISE testing for rheumatology and the new PC4d marker is a critical component of the AVISE SLE Monitor test, intended for use anytime a provider is assessing one of their lupus patients.

“We are the only company developing novel instruments like PC4d for the rheumatology community”, explained Ron Rocca, CEO of Exagen Inc. who continued “We recognize that patients suffering from lupus and related conditions face immense challenges in trying to reduce or control their lupus. The findings that PC4d is associated with a history of thrombosis means that every lupus patient and their doctors will now have access to information about one of the major complications associated with their condition.”

About Exagen Inc.

We are dedicated to transforming the care continuum for patients suffering from debilitating and chronic autoimmune diseases by enabling timely differential diagnosis and optimizing therapeutic intervention. We have developed and are commercializing a portfolio of innovative testing products under our AVISE brand, several of which are based on our proprietary Cell-Bound Complement Activation Products, or CB-CAPs, technology. CB-CAPs assess the activation of the complement system, a biological pathway that is widely implicated across many autoimmune and autoimmune-related diseases, including systemic lupus erythematosus, or SLE. Our goal is to enable rheumatologists to improve care for patients through the differential diagnosis, prognosis and monitoring of complex autoimmune and autoimmune-related diseases, including SLE and rheumatoid arthritis, or RA. Our business model of integrating testing products and therapeutics positions us to offer targeted solutions to rheumatologists and, ultimately, better serve patients.

For more information, visit www.exagen.com or follow us on Facebook, Twitter, YouTube, LinkedIn, or Instagram.

Brian McEvilly
Exagen Inc.

David Clair, Investor Relations
Westwicke Partners