SOUTH SAN FRANCISCO, CA — Diadexus, Inc. (OTCQB: DDXS), a diagnostics company developing and commercializing products that aid in the prediction of cardiac disease risk, today announced that it has entered into an exclusive, license and supply agreement granting OriGene Technologies, Inc. (“OriGene”) rights to develop and commercialize Diadexus’ proprietary PLAC® ELISA in certain Asian countries (“the Territory”).

Under the terms of the agreement, OriGene purchased from Diadexus $1.0 million of Diadexus common stock at a price per share that is a premium to the average 10-day closing price. Diadexus will be responsible for supplying to OriGene the raw materials and reagents necessary to assemble, develop, produce and sell PLAC® ELISA in the Territory. OriGene will seek marketing authorization for the test in the Territory. OriGene has agreed to purchase the PLAC® ELISA test bulk materials exclusively from Diadexus on a cost plus profit basis.

OriGene will submit a marketing authorization dossier for PLAC® ELISA to the regulatory authorities. Following approval, and subject to certain Diadexus quality assurance and quality control specifications, OriGene will have exclusive rights to commercialize market and sell the test in the Territory under the global brand name PLAC® ELISA. Upon commencement of commercial sales, Diadexus will be eligible to receive modest sales-based milestones as well as mid-single-digit royalties on net sales.

“Given their extensive depth and expertise in developing antibody-based immunoassays, OriGene is well equipped to format our raw materials into kits, obtain regulatory authorization, and ultimately bring PLAC® ELISA to market in this important Territory,” said Lori Rafield, Ph.D., chairman and chief executive officer of Diadexus. “As the global incidence of heart disease continues to increase, we have seen a substantial amount of interest in selling the PLAC tests in Asia. This partnership builds on Diadexus’ long standing relationship with OriGene subsidiary, BioCheck Inc., one of our key manufacturers of PLAC® ELISA for many years. We look forward to a successful expanded relationship with the team at OriGene in support of their efforts to introduce the first and only LP-PLA2 test in these valuable markets.”

About PLAC® ELISA

The PLAC® Test ELISA Kit (PLAC® ELISA) measures the concentration of circulating lipoprotein-associated phospholipase A2 (“Lp-PLA2”) in the blood using an enzyme-linked-immunosorbent serologic assay (“ELISA”). The PLAC ELISA Test aids in assessing risk for both coronary heart disease (“CHD”) and ischemic stroke associated with atherosclerosis and designed to provide information, over and above traditional risk factors, such as cholesterol levels, to help identify individuals at increased risk of suffering a heart attack or stroke.

About OriGene Technologies, Inc.

OriGene Technologies, Inc. is a global gene centric life sciences company, founded in 1996, headquartered in Rockville, MD. OriGene develops, manufactures and commercializes antibodies, research and clinical reagents and immunoassay test kits worldwide through its various operating units. The Company has high throughput production capacity with facilities operating under GMP and ISO standards. OriGene serves healthcare institutions, life science researchers, clinical laboratories, pharmaceutical/biotech, and diagnostic companies. For more information, visit www.origene.com.

About Diadexus, Inc.

Diadexus, based in South San Francisco, California, is a diagnostics company developing and commercializing products that aid in the prediction of cardiac disease risk, providing healthcare providers with actionable information for managing patients. The Company pioneered the testing of Lp-PLA2, a marker of vascular-specific inflammation that provides new information, over and above traditional risk factors measured in a lipid panel, and has over a decade of peer-reviewed literature validating its utility. Diadexus’ products, The PLAC® Test ELISA Kit, first cleared by the FDA in 2003, and The PLAC® Test for Lp-PLA2 Activity, cleared in December 2014, are the only two FDA-cleared tests to measure Lp-PLA2.

The Company also has a pipeline of biomarkers for heart failure, proADM, proET-1 and proANP, with each providing distinct, additive information for healthcare providers over currently available markers. Diadexus also provides services to pharmaceutical partners to address the need to incorporate biomarkers in clinical development. For more information, please visit the Company’s website at www.diadexus.com.