diaDexus Announces Data on Lp-PLA2 to be Presented at International Symposium on...

diaDexus Announces Data on Lp-PLA2 to be Presented at International Symposium
on Atherosclerosis

Study Finds Lp-PLA2 is Reduced by About One-Third in Patients Receiving
Lifestyle Intervention and Drug Therapy and that Changes in Lp-PLA2 are Only
Slightly Related to Changes in LDL-C

SOUTH SAN FRANCISCO, Calif., June 16 /PRNewswire/ -- diaDexus, Inc.,
manufacturer of the PLAC(R) Test, today announced seven presentations
involving lipoprotein-associated phospholipase A2 (Lp-PLA2), a novel
inflammatory biomarker and independent predictor for cardiovascular disease,
will be presented at the XV International Symposium on Atherosclerosis (ISA)
convening June 14-17 in Boston, Mass.

Lead author of one of the studies, Kota Reddy, M.D., of Reddy Cardiac
Wellness, Houston, Texas will present his research, "Effects of Lifestyle
Intervention and Combination Lipid Modifying Therapy on Lipoprotein-Associated
Phospholipase A2" today. The study involved 248 patients with mixed lipid
disorders who often present with diabetes or metabolic syndrome. Over a period
of 10.5 months, patients received a combination of lifestyle intervention
including diet and exercise counseling, as well as multiple drug therapies
such as omega-3 fish oil, extended release niacin and statins. Mean Lp-PLA2
values were reduced by 32.5 percent, demonstrating that Lp-PLA2, an
established risk marker for heart disease, can be lowered through lifestyle
changes and drug therapy. The study also examined the relationship between
changes in Lp-PLA2 and LDL cholesterol (LDL-C) and found they were not
strongly linked.

"The primary finding of the study is that Lp-PLA2, a specific marker of
arterial plaque inflammation can be significantly reduced through the practice
of lifestyle modification and drug therapy for patients at high risk," said
Kota Reddy, M.D., lead researcher for the study. "Elevated Lp-PLA2 is a sign
that there is an inflamed plaque in the artery that may be ready to crack.
Perhaps even more significant is the finding that the mechanism of action that
causes the reduction in Lp-PLA2 is different than the processes involved in
reducing LDL-C. This finding may help lead to a better understanding of why
statins reduce stroke risk, independent of changes in cholesterol levels."

The following research involving Lp-PLA2 will also be presented at the ISA on
Tuesday, June 16:

-- "Is Lipoprotein-Associated Phospholipase A2 in high density
lipoprotein a risk factor for coronary vascular disease in the
elderly," poster (#886), presented by M.J. Caslake, PhD.
-- "The prevalence of elevated levels of inflammatory biomarkers
Lp-PLA2 and hs-CRP among apparently healthy young adults," poster
(#827), presented by Kota Reddy, M.D.
-- "Association of Lp-PLA2 with coronary artery disease in African
Americans and Caucasians," poster (#410), presented by Anuurad
Erdembileg, M.D., PhD.
-- "Low prevalence of elevated levels of Lipoprotein-Associated
Phospholipase A2 mass observed among persons with increased levels of
high density lipoprotein cholesterol," poster (#337), presented by
Kota Reddy, M.D.
-- "Novel inflammatory risk markers including Lp-PLA2 and risk of CHD
in patients with familial hypercholesterolaemia (FH)," poster
(#674), presented by M. Seed.

-- "Do novel biomarkers correlate with preclinical
atherosclerosis?" poster (#1189), presented by Andrzej Boguszewski,
M.D.

About the PLAC(R) Test
The PLAC(R) Test is the only FDA-cleared blood test to aid in assessing risk
for coronary heart disease and ischemic stroke associated with
atherosclerosis. The simple blood test measures levels of a novel risk marker,
lipoprotein-associated phospholipase A2 (Lp-PLA2), a vascular specific
inflammatory enzyme implicated in the formation of rupture prone plaque; it is
plaque rupture and thrombosis (major blood clot), not stenosis (narrowing of
the arteries), that causes the vast majority of heart attacks. The PLAC Test
is recommended for patients at moderate to high risk for heart attack or
stroke, according to an expert panel consensus published in a June 2008
supplement to The American Journal of Cardiology.

About diaDexus
diaDexus, Inc., a privately held diagnostics company based in South San
Francisco, is focused on the development and commercialization of
patent-protected in vitro diagnostic products addressing unmet needs in
cardiovascular disease. For more information, visit www.plactest.com or
www.diaDexus.com.

SOURCE diaDexus, Inc.

Sherry Feldberg or Amanda Lazaro, +1-781-684-0770, diadexus@schwartz-pr.com,
both for diaDexus, Inc.