-- Studies of Investigational Anti-Cancer Drug Currently Ongoing --

NEW ORLEANS, June 5 /PRNewswire-FirstCall/ -- An analysis examining pooled data from two clinical studies of atrasentan shows a statistically significant (p=0.013) delay in time to disease progression in men with metastatic, hormone refractory prostate cancer who took the drug versus those who took placebo. Analyzed separately these studies trended toward atrasentan, but did not show statistical significance.

The data were presented today by Michael A. Carducci, M.D., Johns Hopkins Kimmel Cancer Center at the American Society of Clinical Oncology (ASCO) annual meeting.

Atrasentan is an oral, non-hormonal, non-chemotherapy investigational anti-cancer agent. Prostate cancer is the most common solid tumor in American men. An estimated 230,000 men will be diagnosed with prostate cancer and 29,000 will die from the disease this year in the United States.

"These meta-analysis results are encouraging and show that atrasentan holds promise for the treatment of metastatic, hormone-refractory prostate cancer," said Perry Nisen, M.D. Ph.D., divisional vice president, Global Oncology Development at Abbott Laboratories.

Meta-Analysis of M96-594 & M00-211

To examine the overall treatment effect of atrasentan in men with metastatic, hormone refractory prostate cancer, Abbott conducted a simple retrospective pooling of its two large, randomized, well-controlled clinical trials (M96-594 & M00-211) with a total patient population of 1097. Results pooled from two different atrasentan doses (2.5mg and 10mg) demonstrate a statistically significant (p=0.013) delay in time to disease progression in the intent to treat analysis for men taking atrasentan vs. placebo.

The two individual studies pooled for the meta-analysis tested the same patient population with similar baseline demographics, used the same endpoint of time to disease progression (radiographic progression was more explicitly defined in the M00-211 protocol) and were placebo-controlled and double blind. Abbott has conducted statistical tests for heterogeneity of the studies and on the overall treatment effect to support the rigor of the meta-analysis.

Atrasentan (10mg) was generally well tolerated in both studies among all patients. The most common associated adverse events for atrasentan vs. placebo were, headache (21 percent vs. 13 percent), peripheral edema (39 percent vs. 13 percent), and rhinitis (34 vs. 14 percent) respectively.

"A meta-analysis is a useful tool in assessing modest but nevertheless clinically important treatment effects. The combined results from these studies are very encouraging and suggest atrasentan may be an exciting novel treatment option which targets the endothelin axis," said Professor David Dearnaley, MD, FRCP, Institute of Cancer Research/Royal Marsden Hospital. "These are the first trials to explore the benefit of the endothelin-A receptor antagonists in hormone refractory prostate cancer and give rise to optimism than an entirely different class of agents may be valuable after failure of conventional treatments."

About Atrasentan

Atrasentan, an oral, once-daily, non-hormonal, non-chemotherapy, anti-cancer agent, belongs to a class of compounds known as selective endothelin-A receptor antagonists, or SERAs. SERAs antagonize the effect of endothelin (ET-1), one of the proteins thought to be involved in the stimulation of the spread of cancer cells. Atrasentan is the result of Abbott's discovery effort in oncology.

Atrasentan has been studied in Phase II and Phase III clinical trials in patients with metastatic, hormone refractory prostate cancer. It is currently in its second Phase III pivotal trial (M00-244) involving men with prostate cancer that has not spread (non-metastatic). It is also being evaluated in a Phase II trial (M01-366) in men with rising prostate-specific antigen (PSA) following prostate cancer surgery. Additionally, Abbott continues to support the investigation of atrasentan in other cancers including kidney, ovarian, brain, and non-small-cell lung cancers.

Atrasentan has been granted fast track review status from the U.S. Food and Drug Administration (FDA).

About Abbott Laboratories

Abbott Laboratories is committed to the discovery and development of innovative treatments to help patients in the fight against cancer. Abbott's oncology research is focused on developing targeted, less toxic therapies than are currently available. The company has several different classes of compounds in various stages of clinical development. These approaches address multiple phases of cancer progression, including angiogenesis (new blood vessel formation), signal transduction and programmed cell death (apoptosis).

Abbott's Oncology Franchise extends beyond pharmaceutical research to supportive care products and diagnostics. Abbott currently manufactures products for pain management, including patient-controlled analgesia pumps, and markets tests for detection of cancer, including a PSA test. Abbott's innovative genomic tests include Vysis(R) UroVysion, for monitoring the recurrence of bladder cancer, and PathVysion(R), for detecting the HER-2 gene, which predicts potential treatment benefit in women with breast cancer. Abbott also markets nutritional products designed to meet the unique dietary needs of cancer patients.

Abbott Laboratories is a global, broad-based health care company devoted to the discovery, development, manufacture and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs more than 55,000 people and markets its products in more than 130 countries.

SOURCE  Abbott Laboratories
    -0-                             06/05/2004
    /CONTACT:  U.S. Media, Catherine Bryan, +1-847-938-8551, or Cell,
+1-312-209-0250, Media Outside the U.S., Brian Kyhos, +1-847-936-7988, or
Financial Community, John Thomas, +1-847-938-2655, all of Abbott Laboratories/
    /Company News On-Call:  http://www.prnewswire.com/comp/110328.html /
    /Web site:  http://www.abbott.com /
    (ABT)

CO:  Abbott Laboratories; American Society of Clinical Oncology (ASCO) annual
     meeting
ST:  Louisiana, Illinois
IN:  HEA MTC
SU:  SVY TDS

JL-LC 
-- CGSA002 --
8417 06/05/2004 17:30 EDT http://www.prnewswire.com