EUROPEAN UNION'S CPMP RECOMMENDS APPROVAL OF REMICADE(TM) FOR TREATMENT OF CROHN'

EUROPEAN UNION'S CPMP RECOMMENDS APPROVAL OF REMICADE(TM) FOR TREATMENT OF CROHN'S DISEASE Malvern, Pennsylvania and Madison, New Jersey, May 24 - Centocor, Inc., (Nasdaq: CNTO) and Schering-Plough Corporation (NYSE: SGP) announced today that the European Union's (EU) Committee for Proprietary Medicinal Products (CPMP) has issued a positive opinion recommending that REMICADE(TM) (infliximab), Centocor's novel treatment for patients with Crohn's disease, be approved for marketing in Europe. The CPMP opinion serves as the basis for a European Commission (EC) approval, which is typically issued within three to four months of the CPMP's recommendation. Following approval from international regulatory agencies, Schering-Plough will market REMICADE in all countries throughout the world, except in Japan and parts of the Far East where REMICADE will be marketed by Tanabe Seiyaku, Ltd. Centocor has exclusive marketing rights to the product in the United States. Upon EC approval, REMICADE would be indicated for the treatment of severe, active Crohn's disease in patients who have not responded despite a full and adequate course of therapy with a corticosteroid and/or an immunosuppressant. The CPMP also recommended approval for REMICADE as treatment of fistulising Crohn's disease in patients who have not responded despite a full and adequate course of therapy with conventional treatment. If signs and symptoms of the disease recur, REMICADE could be readministered within 14 weeks following the initial treatment regimen. Approval by the EC of the centralised Marketing Authorization Application for REMICADE will result in one single Marketing Authorization with unified labelling that will be valid in all 15 EU-Member States. In the US, REMICADE received Food and Drug Administration (FDA) approval in August 1998 for treatment of moderately to severely active Crohn's disease for the reduction of signs and symptoms in patients who have an inadequate response to conventional therapy and for treatment of patients with fistulising Crohn's disease for the reduction in the number of draining enterocutaneous fistulas. To date, approximately 15,000 patients in the US have been treated with the product. In January 1999, Centocor submitted a supplemental Biologics License Application for REMICADE to the FDA for the treatment of rheumatoid arthritis. Other studies are evaluating REMICADE for the treatment of Crohn's disease in children and for psoriasis. Thousands of patients in Europe are affected by Crohn's disease, a chronic and debilitating disorder of the gastrointestinal tract that can greatly affect a patient's quality of life and often occurs in young adults. The chronic inflammatory nature of the disease can cause fistulas, openings that burrow through the bowel wall into nearby organs or through the surface of the skin. Approximately 20 per cent of Crohn's patients have fistulas. REMICADE is the first of a new class of agents for the treatment of Crohn's disease that block activity of a key biologic response mediator called tumor necrosis factor alpha (TNF-alpha). Overproduction of TNF-alpha leads to inflammation in autoimmune conditions such as Crohn's disease. It is believed that REMICADE reduces intestinal inflammation in patients with Crohn's disease by binding to and neutralising TNF-alpha on the cell membrane and in the blood. This action may explain why REMICADE is a particularly effective inhibitor of TNF-alpha and why REMICADE has a rapid and substantial clinical benefit. In a randomised, placebo-controlled clinical study of 108 patients with moderate-to-severe Crohn's disease who did not respond to conventional therapy, 82 percent of patients treated with REMICADE at the recommended dose (5mg/kg) achieved a clinical response after four weeks compared to 16 per cent of patients who received placebo. In addition, 48 per cent of patients achieved clinical remission against four per cent of patients who received placebo. REMICADE is the first product documented to reduce the number of open fistulas in a controlled clinical trial. In one Phase III clinical study of 94 patients with fistulising Crohn's disease, 68 per cent of patients treated with REMICADE (5 mg/kg) experienced closure of at least 50 per cent of fistulas for four weeks or more compared with 26 per cent of placebo-treated patients. Over half (55 per cent) experienced closure of all their fistulas. These results were reported in a study published in The New England Journal of Medicine (May 5 1999). Approximately five per cent of Crohn's disease patients studied in clinical trials discontinued REMICADE treatment. The most common reasons for discontinuation were infusion reactions and infections. On rare occasions, these reactions were serious but resolved with standard treatment for hypersensitivity reactions or discontinuation of REMICADE therapy. The most common adverse reactions occurring more frequently with REMICADE than with placebo include nausea, upper respiratory tract infections and abdominal pain. REMICADE therapy may result in the development of autoantibodies. However, development of such autoantibodies rarely leads to clinical symptoms or discontinuation of therapy. Centocor is a leading biopharmaceutical company that creates, acquires and markets cost-effective therapies that yield long-term benefits for patients and the healthcare community. Its products, developed primarily through monoclonal antibody technology, help physicians deliver innovative treatments to improve human health and restore patients' quality of life. For more information about REMICADE, visit Centocor's website at http://www.centocor.com. Schering-Plough Corporation is a research-based company engaged in the discovery, development, manufacturing and marketing of pharmaceutical products worldwide. Certain of the matters discussed herein with respect to future earnings, clinical studies and the company's products may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are based on current expectations, estimates and projections about the company's industry, management's beliefs and certain assumptions made by the company's management. Investors are cautioned that matters subject to forward-looking statements involve risks and uncertainties, including economic, competitive, governmental, technological and other factors discussed in the company's filings with the Securities and Exchange Commission, which may affect the company's business and prospects. More specifically, there can be no assurance that this product will achieve commercial success or that competing products will not preempt any market opportunity that might exist for the product. UNS Contact: (media) Christopher Allman, tel Pennsylvania +1 610 651 6546 or (investors) Jason Rubin, tel +1 610 651 6042, both of Centocor or (media) Denise Foy, tel USA +1 973 822 7464 or (investors) Geraldine Foster, tel +1 973 822 7410 or Lisa DeBerardine, tel +1 973 822 7437 or Janet Barth, tel +1 973 822 7417, all of Schering-Plough. Web site: http://www.centocor.com ends lah