Faster reporting aids physicians in identifying HIV mutations that can
inhibit effectiveness of newest class of antiretroviral therapy
MADISON, N.J., June 12 /PRNewswire-FirstCall/ -- Quest Diagnostics
Incorporated (NYSE: DGX), the world's leading provider of diagnostic testing,
information and services, today announced the availability of a new laboratory
developed test designed to help physicians determine whether a patient with a
history of HIV drug resistance will respond to the latest class of HIV
antiretroviral therapies. The HIV-1 Coreceptor Tropism Test, which reports
results in approximately half the time of the nearest competing test, provides
physicians with timely information so they may more quickly determine or
change therapy based on how the HIV virus infects cells in the individual
patient.
"Diagnostic testing is at the center of personalized medicine, providing
genetic insights necessary to understand which medicines are most likely to
produce a favorable health outcome for the individual patient," said Jon R.
Cohen, M.D., senior vice president and chief medical officer, Quest
Diagnostics. "Our new HIV tropism test will advance personalized medicine for
HIV by helping physicians identify suitable patients for a particular therapy
and ensure those who are not suitable do not lose precious treatment time
potentially better spent on a different drug."
HIV coreceptor tropism refers to the preference of strains of HIV to bind
to, activate and infect cells, promoting disease progression, based on the
type of coreceptor on the cell's surface. The newest class of antiretroviral
drugs, called entry inhibitors, targets the tropism process involving one or
both coreceptors, CCR5 or CXCR4, of CD4 cells, which help the immune system
fight infection. HIV-1 viral particles that use the CCR5 coreceptor to infect
the cell are called R5-tropic, those using CXCR4 are called X4-tropic, and
those using both are called dual-tropic. X4- and dual-tropic viruses typically
emerge after years of infection and are found in up to half of patients with a
history of drug resistance or those with advanced disease. Guidelines from the
U.S. Department of Health and Human Services recommend tropism testing prior
to the start of a CCR5 inhibitor, such as maraviroc (Selzentry TM). Three out
of four people taking HIV drugs experience treatment failure linked to drug
resistance.
"CCR5 antagonist entry inhibitors have given physicians new options for
treating thousands of patients with HIV who have shown resistance to earlier
HIV therapies. Yet, they are only suitable for about half of these patients
due to different ways the virus tries to infect cells," said Jay G.
Wohlgemuth, M.D., vice president of Science and Innovation, Quest Diagnostics.
"With our new tropism test, we expect to report results within seven days of
receiving a patient specimen, compared to the leading commercial HIV tropism
test, which requires two weeks of processing time once a sample is received.
Considering that tropism status can change in as little as a few weeks in
patients with a history of HIV drug resistance, faster results potentially
translate into earlier initiation of efficacious therapy."
At the XVIII International HIV Drug Resistance Workshop in Fort Meyers,
Florida, Quest Diagnostics scientists yesterday presented results of a
three-way study using samples from patients with histories of drug resistance
that found that the Quest Diagnostics HIV-1 Coreceptor Tropism laboratory
developed test demonstrated 74 percent agreement with Trofile(TM), the leading
phenotypic tropism test available from Monogram Biosciences, and 74 percent
agreement with SensiTrop(TM) II, a genotypic tropism test previously available
from Pathway Diagnostics. The SensiTrop(TM) II test, which is no longer
commercially available, was 73 percent in agreement with Trofile(TM) . The
Quest Diagnostics investigators concluded that the concordance between the two
independently developed genotypic tropism tests was comparable to the
concordance of each assay with the Trofile, and that the proportion of X4
viruses detected did not vary significantly by assay type.
Quest Diagnostics had offered a prior version of the SensiTrop test
through a license with Pathway Diagnostics before acquiring the company during
the fourth quarter 2008. The company's new HIV-1 Coreceptor test employs a
novel molecular-based technology developed by Quest Diagnostics scientists.
The Quest Diagnostics HIV laboratory testing services menu is the most
comprehensive in the diagnostic industry. In addition to HIV tropism testing,
the company's test services range from HIV diagnostic testing to monitoring
HIV viral load, determining a viral genotype, and testing for the HLA-B*5701
genetic marker as an aid in predicting a hypersensitivity reaction to abacavir
(Ziagen(R)), an antiretroviral therapy.
About HIV and AIDS
HIV, or the human immunodeficiency virus, is a retrovirus that infects
cells of the human immune system, destroying or impairing their function. The
two major viruses that cause AIDS are HIV-1 and HIV-2. The most common, HIV-1,
is found worldwide, while HIV-2 is primarily confined to West Africa. The most
advanced stage of HIV infection is AIDS, or acquired immunodeficiency
syndrome. HIV can take up to 15 years to develop into AIDS, a process that
antiretroviral drugs can help delay. The World Health Organization estimates
that approximately 1.2 million people over the age of 15 in the U.S. were
infected with HIV in 2005, the most recent year for which data is available.
HIV antiretroviral therapy (ART) is designed to suppresses or stop HIV disease
progression.
About Quest Diagnostics
Quest Diagnostics is the world's leading provider of diagnostic testing,
information and services that patients and doctors need to make better
healthcare decisions. The company offers the broadest access to diagnostic
testing services through its network of laboratories and patient service
centers, and provides interpretive consultation through its extensive medical
and scientific staff. Quest Diagnostics is a pioneer in developing innovative
diagnostic tests and advanced healthcare information technology solutions that
help improve patient care. Additional company information is available at
www.QuestDiagnostics.com.
The statements in this press release which are not historical facts may be
forward-looking statements. Readers are cautioned not to place undue reliance
on forward-looking statements, which speak only as of the date that they are
made and which reflect management's current estimates, projections,
expectations or beliefs and which involve risks and uncertainties that could
cause actual results and outcomes to be materially different. Risks and
uncertainties that may affect the future results of the company include, but
are not limited to, adverse results from pending or future government
investigations, lawsuits or private actions, the competitive environment,
changes in government regulations, changing relationships with customers,
payers, suppliers and strategic partners and other factors discussed in
"Business" in Part I, Item 1, "Risk Factors" and "Cautionary Factors that May
Affect Future Results" in Part I, Item 1A, "Legal Proceedings" in Part I, Item
3, "Management's Discussion and Analysis of Financial Condition and Results of
Operations" in Part II, Item 7 and "Quantitative and Qualitative Disclosures
About Market Risk" in Part II, Item 7A in the company's 2008 Annual Report on
Form 10-K and "Management's Discussion and Analysis of Financial Condition and
Results of Operations" and "Quantitative and Qualitative Disclosures About
Market Risk" in the company's 2009 Quarterly Report on Form 10-Q and other
items throughout the Form 10-K and the company's 2009 Quarterly Reports on
Form 10-Q and Current Reports on Form 8-K.
Trofile is a trademark of Monogram Biosciences, Inc.
Selzentry is a trademark of Pfizer Inc.
ZIAGEN(R) is a registered trademark, used under license by GlaxoSmithKline
Inc.
Quest, Quest Diagnostics, the associated logo, Nichols Institute and all
associated Quest Diagnostics marks are the registered trademarks of Quest
Diagnostics.
All third party marks -- (R)' and (TM)' -- are the property of their
respective owners.
(C) 2000-2009 Quest Diagnostics Incorporated. All rights reserved.
Quest Diagnostics Contacts:
Laure Park (Investors): 973-520-2900
Wendy Bost (Media): 973-520-2800
SOURCE Quest Diagnostics Incorporated