Abbott Park, Illinois, March 3, 2003 — Abbott Laboratories announced today the expansion of its immunology clinical trials program to include studies evaluating the potential of HUMIRA™ (adalimumab) in psoriasis and psoriatic arthritis. Psoriasis and psoriatic arthritis are autoimmune disorders in which a human protein, tumor necrosis factor-alpha (TNF-á), has been suggested to play a role in the disease development. Data from clinical studies suggest that treatments that inhibit TNF-á may be effective in these disease states. HUMIRA, which is a human monoclonal antibody that resembles antibodies normally found in the body, works by specifically blocking TNF-á.

HUMIRA is the first human monoclonal antibody approved by the U.S. Food and Drug Administration (FDA) for reducing the signs and symptoms and inhibiting the progression of structural damage in adults with moderately to severely active rheumatoid arthritis (RA) who have had insufficient response to one or more traditional disease modifying antirheumatic drugs (DMARDs) and can be used alone or in combination with methotrexate (MTX) or other DMARDs. HUMIRA was created using phage display technology, resulting in an antibody with human-derived heavy and light chains variable regions and human IgG1:K constant regions. The European Agency for the Evaluation of Medicinal Products (EMEA) accepted Abbott's submission for HUMIRA for the treatment of RA in April 2002, and approval is anticipated in mid-2003.

"Abbott is committed to exploring the full therapeutic potential of HUMIRA," said Jim Lefkowith, M.D., divisional vice president, Immunosciences Development, Abbott Laboratories. "Based on the recent approval of HUMIRA for rheumatoid arthritis, we're excited to be initiating programs that will help us understand the effect of HUMIRA in other autoimmune diseases as well."

Psoriasis Trial
HUMIRA will be studied in a randomized, multicenter, Phase II clinical trial that will assess safety and efficacy in adult patients with moderate to severe chronic-plaque psoriasis. Patient response to treatment will be assessed by using the Psoriasis Area Severity Index score, which is a measure of a patient's disease activity.

"We’re hoping that this trial will lead to an available treatment option for the more than four million Americans living with psoriasis," said Ken Gordon, M.D., associate professor of medicine, division of dermatology, Loyola University Medical Center. "Psoriasis can have a significant emotional and psychological impact on a patient's quality of life and by investigating the use of HUMIRA in psoriasis, we’re hoping to see improvements in treating the disease."

Psoriasis is a non-contagious, chronic skin disease characterized by red plaques covered with white scales that presents in different forms and varying degrees of severity. The most common form of psoriasis is "plaque psoriasis," which accounts for approximately 80 percent of psoriasis cases. Plaque psoriasis can appear on any skin surface, although the knees, elbows, scalp, and trunk are the most common locations.

Psoriatic Arthritis Trial
A Phase III study has been initiated that will evaluate HUMIRA in improving signs and symptoms of psoriatic arthritis in adult patients with moderate to severe disease. Patients in the trial will be randomized to receive HUMIRA or placebo, and responses will be measured by improvements in signs and symptoms as measured by American College of Rheumatology response scores.

"Psoriatic arthritis patients experience the often unmanageable symptoms of arthritis combined with psoriasis," said Philip Mease, M.D., clinical professor of rheumatology at the University of Washington. "This trial is designed to assess the effect of HUMIRA in the treatment of these patients and on the progression of the disease."

Flares and remissions characterize the course of psoriatic arthritis, which is an autoimmune disease. If left untreated it can be a progressively disabling disease. The arthritic manifestations often include not only debilitating disease of the hands and feet as is seen in rheumatoid arthritis, but also arthritis of the spine and painful inflammation of tendon insertions. Epidemiological studies indicate that psoriatic arthritis affects as many as 30 percent of the people who have psoriasis. Common symptoms include varying degrees of psoriasis activity along with stiffness, pain, swelling and tenderness of the joints that can lead to a reduced range of motion and potential severe joint destruction.

More information about HUMIRA clinical trials can be obtained by calling Abbott Medical Information at 1-800-633-9110.

Important Safety Information
Cases of tuberculosis (TB), frequently disseminated or extra pulmonary at clinical presentation have been observed in patients receiving HUMIRA. Serious infections and sepsis, including fatalities, have been reported with the use of TNF-blocking agents, including HUMIRA. Many of these infections occurred in patients on concomitant immunosuppressive therapy that in addition to their underlying disease could predispose them to infections. Other invasive opportunistic fungal infections have also been observed in patients treated with TNF-blocking agents, including HUMIRA.

TNF-blocking agents, including HUMIRA, have been associated in rare cases with exacerbation of demyelinating disease. The most frequent adverse events seen in the placebo-controlled clinical trials (HUMIRA vs. placebo) were upper respiratory infection (17 percent vs. 13 percent), injection site pain (12 percent vs. 12 percent), headache (12 percent vs. 8 percent), rash (12 percent vs. 6 percent) and sinusitis (11 percent vs. 9 percent). Discontinuations due to adverse events were 7 percent for HUMIRA and 4 percent for placebo. As with any treatment program, the benefits and risks of HUMIRA should be carefully considered before initiating therapy.

About HUMIRA
HUMIRA was discovered through a broad scientific collaboration between Abbott and Cambridge Antibody Technology (CAT). As part of the collaboration, Abbott had the right to select several target antigens for which a joint Abbott/CAT research team would discover human antibody therapeutics. HUMIRA was isolated and optimized by Abbott and CAT as part of this collaboration. Abbott owns exclusive worldwide rights to HUMIRA, including responsibility for clinical development, manufacturing, sales and marketing. Abbott will book all revenues for HUMIRA, and CAT will receive a royalty fee based on HUMIRA sales.

Additionally, clinical trials are currently underway evaluating the potential of HUMIRA in juvenile rheumatoid arthritis (JRA) and Crohn's disease.

Abbott's Commitment to Immunology
Abbott Laboratories is committed to the discovery and development of innovative treatments for immunologic diseases. Founded in 1989, the Abbott Bioresearch Center in Worcester, Massachusetts, is a world-class discovery and basic research facility committed to finding new treatments for autoimmune diseases. Abbott Bioresearch Center employs leading-edge technologies, discovery and manufacturing processes, including proprietary phage antibody display technology, and mammalian cell expression systems to produce fully human monoclonal antibodies.

In January 2003, Abbott announced the initiation of the HUMIRA Medicare Assistance Program, which ensures that Medicare-eligible seniors in need of a biologic treatment for rheumatoid arthritis who do not have prescription drug coverage can receive HUMIRA at no cost until a Medicare prescription drug benefit is enacted. Eligible seniors can receive HUMIRA directly from their health care provider, and access continues as long as they continue to meet the eligibility criteria.