Quest Diagnostics Launches the First Tests to Help Doctors Assess Status of Leukemia and Lymphoma in Patients Using Blood Plasma Instead of Bone Marrow

Nearly 1 million Americans who are battling or recovering from leukemia and lymphoma have a powerful new diagnostic tool available as Quest Diagnostics Incorporated (NYSE: DGX) today launches the first of its LEUMETA(TM) cancer testing assays, a new family of laboratory-developed tests that may, in the future, provide an alternative to painful bone marrow biopsies.

As the nation's leading provider of diagnostic testing, information and services, Quest Diagnostics developed LEUMETA to identify and analyze genetic components of leukemia and lymphoma tumors using blood plasma instead of bone marrow. The assays are designed to measure "tumor load," or the amount of cancer in a patient; detect certain blood cancer markers; and assist the physician in monitoring the impact of treatment. They are the first diagnostic assays available to doctors that directly measure tumor load and identify markers in blood plasma.

"LEUMETA assays have the potential to help doctors personalize the way they practice medicine by providing information about the status of leukemia and lymphoma in blood plasma to help the physician determine the drug and dosage that works best for each patient, based on the specifics of that patient's cancer and other clinical information available to the physician," said Surya N. Mohapatra, Ph.D., Chairman and Chief Executive Officer of Quest Diagnostics. "More prospective studies are needed, but in the meantime, sample collection for these blood plasma assays developed from this technology will be less painful than for bone marrow tests, while offering doctors a new tool to assess the status of these cancers."

While conventional tests look for cancer cells in bone marrow or, in certain cases, peripheral blood, LEUMETA cancer assays track genetic components of leukemia and lymphoma tumors, including messenger RNA, DNA and protein in blood plasma -- the liquid portion of the blood. Studies performed at Quest Diagnostics and The University of Texas M. D. Anderson Cancer Center and presented at the American Society of Hematology (ASH) meeting in December 2005 showed that information about tumor load and blood cancer markers of leukemia and lymphoma tumors is contained in blood plasma. Sample collection for these LEUMETA assays does not require the painful extraction of bone marrow cells with a large-bore needle through the hipbone.

"Using these tests, doctors can get a more frequent indication of a patient's disease status and decide whether to alter their treatment," explained Francis Giles, M.D., Professor of Medicine and Chief of Developmental Therapeutics within the Department of Leukemia at the M.D. Anderson Cancer Center, Houston. "In an era of increasing focus on targeted therapies, the ability to sequentially obtain so much data from blood plasma specimens is a major help in optimally using the available therapies, and in assessing the efficacy of novel agents. To obtain this data without the need for bone marrow tissue is a major advance."

Developed by a team of researchers at Quest Diagnostics using licensed technology discovered by one of the researchers while previously at M.D. Anderson Cancer Center, LEUMETA cancer assays are available to physicians and oncology programs nationwide through Quest Diagnostics. For more information about the full range of currently available LEUMETA cancer tests, please visit www.questdiagnostics.com.

LEUMETA cancer assays look for a variety of clinical disease markers in blood plasma to assist the physician in diagnosing and monitoring major types of leukemia and lymphoma. For example, as one study indicates, one of the tests identifies a protein tumor marker called the bcr-abl fusion protein that signals how well Chronic Myeloid Leukemia (CML) patients are responding to treatment. Another assay in the family, called ABL Kinase Domain Mutation, Plasma-based, LEUMETA, reveals genetic mutations of the ABL gene that suggest a more aggressive form of leukemia or may be indicative of resistance to therapy.

"Some of these new assays provide physicians with a direct measure of tumor load, or the amount of cancer within a patient's body. Others provide a more convenient way to detect the presence or absence of tumor markers. As a result, they provide a new tool to assess disease status," said Maher Albitar, M.D., Medical Director for Hematopathology at Quest Diagnostics, and lead developer of the LEUMETA assays. "Oncologists may now use LEUMETA cancer tests to assess patients more frequently, permitting closer monitoring of the patient's progress on therapy, allowing the oncologist to interpret the results more frequently and to tailor treatment accordingly."

Some current cancer treatment drugs work by inhibiting phosphorylation of oncoproteins. By measuring phosphorylated proteins in plasma, LEUMETA may in the future help doctors predict how well these drugs are binding and fighting cancer. As a result, doctors may one day be able to tailor therapy to the specific profiles and requirements of each patient.